Fix unmatched_returns warnings in STDLIB and Kernel

63 files changed, 465 insertions, 361 deletions

diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index 61d8df2428..87003d096b 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -1045,7 +1045,7 @@ start_it({eval,Bin}) ->
 	      TsR -> reverse([{dot,1} | TsR])
 	  end,
     {ok,Expr} = erl_parse:parse_exprs(Ts1),
-    erl_eval:exprs(Expr, erl_eval:new_bindings()),
+    {value, _Value, _Bs} = erl_eval:exprs(Expr, erl_eval:new_bindings()),
     ok;
 start_it([_|_]=MFA) ->
     Ref = make_ref(),
diff --git a/erts/preloaded/src/prim_zip.erl b/erts/preloaded/src/prim_zip.erl
index d29f17ae56..1d5ab52a24 100644
--- a/erts/preloaded/src/prim_zip.erl
+++ b/erts/preloaded/src/prim_zip.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2008-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2008-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -89,7 +89,7 @@ do_open(FilterFun, FilterAcc, F) ->
 	{ok, PrimZip2, FilterAcc2}
     catch
 	Class:Reason ->
-	    close(PrimZip),
+	    _ = close(PrimZip),
 	    erlang:error(erlang:raise(Class, Reason, erlang:get_stacktrace()))
     end.
 
diff --git a/erts/preloaded/src/zlib.erl b/erts/preloaded/src/zlib.erl
index 1faae1c1f4..2c9d55f50c 100644
--- a/erts/preloaded/src/zlib.erl
+++ b/erts/preloaded/src/zlib.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2003-2012. All Rights Reserved.
+%% Copyright Ericsson AB 2003-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -206,7 +206,7 @@ deflate(Z, Data) ->
 deflate(Z, Data, Flush) ->
     try port_command(Z, Data) of
 	true ->
-	    call(Z, ?DEFLATE, <<(arg_flush(Flush)):32>>),
+	    _ = call(Z, ?DEFLATE, <<(arg_flush(Flush)):32>>),
 	    collect(Z)
     catch 
 	error:_Err ->
@@ -252,7 +252,7 @@ inflateReset(Z) ->
 inflate(Z, Data) ->
     try port_command(Z, Data) of
 	true -> 
-	    call(Z, ?INFLATE, <<?Z_NO_FLUSH:32>>),
+	    _ = call(Z, ?INFLATE, <<?Z_NO_FLUSH:32>>),
 	    collect(Z)
     catch 
 	error:_Err ->
diff --git a/lib/debugger/src/dbg_icmd.erl b/lib/debugger/src/dbg_icmd.erl
index b230efaa7a..b1bf4ebecc 100644
--- a/lib/debugger/src/dbg_icmd.erl
+++ b/lib/debugger/src/dbg_icmd.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -399,7 +399,7 @@ eval_restricted({From,_Mod,Cmd,SP}, Bs) ->
 
 eval_nonrestricted({From,Mod,Cmd,SP}, Bs, #ieval{level=Le}) when SP < Le->
     %% Evaluate in stack
-    eval_restricted({From, Mod, Cmd, SP}, Bs),
+    _ = eval_restricted({From, Mod, Cmd, SP}, Bs),
     Bs;
 eval_nonrestricted({From, _Mod, Cmd, _SP}, Bs, 
 		   #ieval{level=Le,module=M,line=Line}=Ieval) ->
@@ -465,7 +465,8 @@ tell_attached(Msg) ->
     case get(attached) of
 	undefined -> ignore;
 	AttPid ->
-	    AttPid ! {self(), Msg}
+	    AttPid ! {self(), Msg},
+            ignore
     end.
 
 %%====================================================================
diff --git a/lib/kernel/src/application_controller.erl b/lib/kernel/src/application_controller.erl
index 9ed2c7a7d9..1a4473593a 100644
--- a/lib/kernel/src/application_controller.erl
+++ b/lib/kernel/src/application_controller.erl
@@ -488,7 +488,7 @@ init(Init, Kernel) ->
 	    %% called during start-up of any app.
 	    case check_conf_data(ConfData) of
 		ok ->
-		    ets:new(ac_tab, [set, public, named_table]),
+		    _ = ets:new(ac_tab, [set, public, named_table]),
 		    S = #state{conf_data = ConfData},
 		    {ok, KAppl} = make_appl(Kernel),
 		    case catch load(S, KAppl) of
@@ -1949,10 +1949,10 @@ test_change_apps(Apps, Conf) ->
 test_do_change_appl([], _, _) ->
     ok;
 test_do_change_appl([A|Apps], [], [R|Res]) ->
-    do_change_appl(R, #appl{name = A}, []),
+    _ = do_change_appl(R, #appl{name = A}, []),
     test_do_change_appl(Apps, [], Res);
 test_do_change_appl([A|Apps], [C|Conf], [R|Res]) ->
-    do_change_appl(R, #appl{name = A}, C),
+    _ = do_change_appl(R, #appl{name = A}, C),
     test_do_change_appl(Apps, Conf, Res).
 
 test_make_apps([], Res) ->
diff --git a/lib/kernel/src/application_master.erl b/lib/kernel/src/application_master.erl
index 34a3efcaf2..68f78c6eb8 100644
--- a/lib/kernel/src/application_master.erl
+++ b/lib/kernel/src/application_master.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -125,7 +125,7 @@ init(Parent, Starter, ApplData, Type) ->
     State = #state{appl_data = ApplData, gleader = OldGleader},
     case start_it(State, Type) of
 	{ok, Pid} ->          % apply(M,F,A) returned ok
-	    set_timer(ApplData#appl_data.maxT),
+	    ok = set_timer(ApplData#appl_data.maxT),
 	    unlink(Starter),
 	    proc_lib:init_ack(Starter, {ok,self()}),
 	    main_loop(Parent, State#state{child = Pid});
@@ -418,4 +418,6 @@ kill_all_procs_1([], _, 0) -> ok;
 kill_all_procs_1([], _, _) -> kill_all_procs().
 
 set_timer(infinity) -> ok;
-set_timer(Time) -> timer:exit_after(Time, timeout).
+set_timer(Time) ->
+    {ok, _} = timer:exit_after(Time, timeout),
+    ok.
diff --git a/lib/kernel/src/auth.erl b/lib/kernel/src/auth.erl
index 7d463103e3..eda35147d3 100644
--- a/lib/kernel/src/auth.erl
+++ b/lib/kernel/src/auth.erl
@@ -324,7 +324,7 @@ read_cookie(Name, Size) ->
 	{ok, File} ->
 	    case file:read(File, Size) of
 		{ok, List} ->
-		    file:close(File),
+		    ok = file:close(File),
 		    check_cookie(List, []);
 		{error, Reason} ->
 		    make_error(Name, Reason)
@@ -376,7 +376,7 @@ create_cookie(Name) ->
     case file:open(Name, [write, raw]) of
 	{ok, File} ->
 	    R1 = file:write(File, Cookie),
-	    file:close(File),
+	    ok = file:close(File),
 	    R2 = file:raw_write_file_info(Name, make_info(Name)),
 	    case {R1, R2} of
 		{ok, ok} ->
diff --git a/lib/kernel/src/code.erl b/lib/kernel/src/code.erl
index 03fba96d4b..0eda558ed5 100644
--- a/lib/kernel/src/code.erl
+++ b/lib/kernel/src/code.erl
@@ -364,7 +364,7 @@ load_code_server_prerequisites() ->
 	      lists,
 	      os,
 	      unicode],
-    [M = M:module_info(module) || M <- Needed],
+    _ = [M = M:module_info(module) || M <- Needed],
     ok.
 
 do_stick_dirs() ->
diff --git a/lib/kernel/src/code_server.erl b/lib/kernel/src/code_server.erl
index 5d74e8620b..9358e2201e 100644
--- a/lib/kernel/src/code_server.erl
+++ b/lib/kernel/src/code_server.erl
@@ -153,7 +153,7 @@ loop(#state{supervisor=Supervisor}=State0) ->
 	{code_call, Pid, Req} ->
 	    case handle_call(Req, {Pid, call}, State0) of
 		{reply, Res, State} ->
-		    reply(Pid, Res),
+		    _ = reply(Pid, Res),
 		    loop(State);
 		{noreply, State} ->
 		    loop(State);
@@ -1505,13 +1505,13 @@ finish_on_load_1(Mod, File, OnLoadRes, WaitingPids, Db) ->
     erlang:finish_after_on_load(Mod, Keep),
     Res = case Keep of
 	      false ->
-		  finish_on_load_report(Mod, OnLoadRes),
+		  _ = finish_on_load_report(Mod, OnLoadRes),
 		  {error,on_load_failure};
 	      true ->
 		  ets:insert(Db, {Mod,File}),
 		  {module,Mod}
 	  end,
-    [reply(Pid, Res) || Pid <- WaitingPids],
+    _ = [reply(Pid, Res) || Pid <- WaitingPids],
     ok.
 
 finish_on_load_report(_Mod, Atom) when is_atom(Atom) ->
diff --git a/lib/kernel/src/disk_log.erl b/lib/kernel/src/disk_log.erl
index c238eff12f..9a7726cfa0 100644
--- a/lib/kernel/src/disk_log.erl
+++ b/lib/kernel/src/disk_log.erl
@@ -1076,13 +1076,13 @@ log_end(S, [], [], Sync) ->
 log_end(S, Pids, Bins, Sync) ->
     case do_log(get(log), rflat(Bins)) of
 	N when is_integer(N) ->
-	    replies(Pids, ok),
+	    ok = replies(Pids, ok),
 	    S1 = (state_ok(S))#state{cnt = S#state.cnt+N},
 	    log_end_sync(S1, Sync);
         {error, {error, {full, _Name}}, N} when Pids =:= [] ->
             log_end_sync(state_ok(S#state{cnt = S#state.cnt + N}), Sync);
 	{error, Error, N} ->
-	    replies(Pids, Error),
+	    ok = replies(Pids, Error),
 	    state_err(S#state{cnt = S#state.cnt + N}, Error)
     end.
 
@@ -1091,7 +1091,7 @@ log_end_sync(S, []) ->
     S;
 log_end_sync(S, Sync) ->
     Res = do_sync(get(log)),
-    replies(Sync, Res),
+    ok = replies(Sync, Res),
     state_err(S, Res).
 
 %% Inlined.
@@ -1183,7 +1183,7 @@ do_exit(S, From, Message0, Reason) ->
 		  _ -> Message0
 	      end,
     _ = disk_log_server:close(self()),
-    replies(From, Message),
+    ok = replies(From, Message),
     ?PROFILE(ep:done()),
     exit(Reason).
 
@@ -1881,7 +1881,8 @@ replies(Pids, Reply) ->
     send_reply(Pids, M).
 
 send_reply(Pid, M) when is_pid(Pid) ->
-    Pid ! M;
+    Pid ! M,
+    ok;
 send_reply([Pid | Pids], M) ->
     Pid ! M,
     send_reply(Pids, M);
@@ -2022,7 +2023,7 @@ notify_owners(Note) ->
 
 cache_error(S, Pids) ->
     Error = S#state.cache_error,
-    replies(Pids, Error),
+    ok = replies(Pids, Error),
     state_err(S#state{cache_error = ok}, Error).
 
 state_ok(S) ->
diff --git a/lib/kernel/src/disk_log_1.erl b/lib/kernel/src/disk_log_1.erl
index 9d431bdd30..59f5cad001 100644
--- a/lib/kernel/src/disk_log_1.erl
+++ b/lib/kernel/src/disk_log_1.erl
@@ -295,12 +295,18 @@ read_chunk_ro(FdC, FileName, Pos, MaxBytes) ->
     pread(FdC, FileName, Pos + ?HEADSZ, MaxBytes).
 
 %% -> ok | throw(Error)
-close(#cache{fd = Fd, c = []}, _FileName, read_only) ->
-    file:close(Fd);
+close(#cache{fd = Fd, c = []}, FileName, read_only) ->
+    case file:close(Fd) of
+        ok -> ok;
+        Error -> file_error(FileName, Error)
+    end;
 close(#cache{fd = Fd, c = C}, FileName, read_write) ->
     {Reply, _NewFdC} = write_cache(Fd, FileName, C),
     mark(Fd, FileName, ?CLOSED),
-    file:close(Fd),
+    case file:close(Fd) of
+        ok -> ok;
+        Error -> file_error(FileName, Error)
+    end,
     if Reply =:= ok -> ok; true -> throw(Reply) end.
 
 %% Open an internal file. Head is ignored if Mode is read_only.
@@ -320,7 +326,10 @@ int_open(FName, Repair, read_write, Head) ->
 		{ok, FileHead} ->
 		    case is_head(FileHead) of
 			yes ->
-			    file:close(Fd),
+                            case file:close(Fd) of
+                                ok -> ok;
+                                Error2 -> file_error(FName, Error2)
+                            end,
 			    case open_update(FName) of
 				{ok, Fd2} ->
 				    mark(Fd2, FName, ?OPENED),
@@ -333,14 +342,14 @@ int_open(FName, Repair, read_write, Head) ->
 			yes_not_closed when Repair ->
 			    repair(Fd, FName);
 			yes_not_closed when not Repair ->
-			    file:close(Fd),
+			    _ = file:close(Fd),
 			    throw({error, {need_repair, FName}});
 			no ->
-			    file:close(Fd),
+			    _ = file:close(Fd),
 			    throw({error, {not_a_log_file, FName}})
 		    end;
 		eof ->
-		    file:close(Fd),
+		    _= file:close(Fd),
 		    throw({error, {not_a_log_file, FName}});
 		Error ->
 		    file_error_close(Fd, FName, Error)
@@ -363,11 +372,11 @@ int_open(FName, _Repair, read_only, _Head) ->
                             FdC = #cache{fd = Fd},
 			    {ok, {existed, FdC, {0, 0}, P}};
 			no ->
-			    file:close(Fd),
+			    _= file:close(Fd),
 			    throw({error, {not_a_log_file, FName}})
 		    end;
 		eof ->
-		    file:close(Fd),
+		    _ = file:close(Fd),
 		    throw({error, {not_a_log_file, FName}});
 		Error ->
 		    file_error_close(Fd, FName, Error)
@@ -398,7 +407,7 @@ int_log_head(Fd, Head) ->
 	none ->
 	    {#cache{fd = Fd}, 0, 0};
 	Error -> 
-	    file:close(Fd),
+	    _= file:close(Fd),
 	    throw(Error)
     end.
     
@@ -450,13 +459,13 @@ ext_log_head(Fd, Head) ->
 	none ->
 	    {#cache{fd = Fd}, {0, 0}};
 	Error -> 
-            file:close(Fd),
+            _= file:close(Fd),
 	    throw(Error)
     end.
     
 %% -> _Any | throw()
 mark(Fd, FileName, What) ->
-    position_close2(Fd, FileName, 4),
+    {ok, _} = position_close2(Fd, FileName, 4),
     fwrite_close2(Fd, FileName, What).
 
 %% -> {ok, Bin} | Error
@@ -560,7 +569,7 @@ scan_f2(B, FSz, Ack, No, Bad, Size, Tail) ->
     end.
 
 done_scan(In, Out, OutName, FName, RecoveredTerms, BadChars) ->
-    file:close(In),
+    _ = file:close(In),
     case catch fclose(Out, OutName) of
         ok ->
             case file:rename(OutName, FName) of
@@ -574,21 +583,21 @@ done_scan(In, Out, OutName, FName, RecoveredTerms, BadChars) ->
                             file_error(FName, Error)
                     end;
                 Error ->
-                    file:delete(OutName),
+                    _ = file:delete(OutName),
                     file_error(FName, Error)
             end;
         Error ->
-            file:delete(OutName),
+            _ = file:delete(OutName),
             throw(Error)
     end.
 
 -spec repair_err(file:io_device(), #cache{}, file:filename(),
 		 file:filename(), {'error', file:posix()}) -> no_return().
 repair_err(In, Out, OutName, ErrFileName, Error) ->
-    file:close(In),
+    _= file:close(In),
     catch fclose(Out, OutName),
     %% OutName is often the culprit, try to remove it anyway...
-    file:delete(OutName), 
+    _ = file:delete(OutName),
     file_error(ErrFileName, Error).
 
 %% Used by wrap_log_reader.
@@ -764,10 +773,10 @@ mf_int_chunk(Handle, {FileNo, Pos}, Bin, N) ->
 	{ok, {_Alloc, FdC, _HeadSize, _FileSize}} ->
 	    case chunk(FdC, FName, Pos, Bin, N) of
 		{NewFdC, eof} ->
-		    file:close(NewFdC#cache.fd),
+		    _ = file:close(NewFdC#cache.fd),
 		    mf_int_chunk(Handle, {NFileNo, 0}, [], N);
 		{NewFdC, Other} ->
-		    file:close(NewFdC#cache.fd),
+		    _ = file:close(NewFdC#cache.fd),
 		    {Handle, conv(Other, FileNo)}
 	    end
     end.
@@ -792,10 +801,10 @@ mf_int_chunk_read_only(Handle, {FileNo, Pos}, Bin, N) ->
 	{ok, {_Alloc, FdC, _HeadSize, _FileSize}} ->
 	    case do_chunk_read_only(FdC, FName, Pos, Bin, N) of
 		{NewFdC, eof} ->
-		    file:close(NewFdC#cache.fd),
+		    _ = file:close(NewFdC#cache.fd),
 		    mf_int_chunk_read_only(Handle, {NFileNo,0}, [], N);
 		{NewFdC, Other} ->
-		    file:close(NewFdC#cache.fd),
+		    _ = file:close(NewFdC#cache.fd),
 		    {Handle, conv(Other, FileNo)}
 	    end
     end.
@@ -1017,7 +1026,7 @@ ext_file_open(FName, NewFile, OldFile, OldCnt, Head, Repair, Mode) ->
 
 read_index_file(truncate, FName, MaxF) ->
     remove_files(FName, 2, MaxF),
-    file:delete(?index_file_name(FName)),
+    _ = file:delete(?index_file_name(FName)),
     {1, 0, 0, 0};
 read_index_file(_, FName, _MaxF) ->
     read_index_file(FName).
@@ -1043,7 +1052,7 @@ read_index_file(FName) ->
 		    _ErrorOrEof ->
 			{1, 0, 0, 0}
 		end,
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    R;
 	_Error ->
 	    {1, 0, 0, 0}
@@ -1096,7 +1105,7 @@ write_index_file(read_write, FName, NewFile, OldFile, OldCnt) ->
                         %% Very old format, convert to the latest format!
 			case file:read_file(FileName) of
 			    {ok, <<_CurF, Tail/binary>>} ->
-				position_close2(Fd, FileName, bof),
+				{ok, _} = position_close2(Fd, FileName, bof),
 				Bin = <<0, 0:32, ?VERSION, NewFile:32>>,
 				NewTail = to_8_bytes(Tail, [], FileName, Fd),
 				fwrite_close2(Fd, FileName, [Bin | NewTail]),
@@ -1115,7 +1124,7 @@ write_index_file(read_write, FName, NewFile, OldFile, OldCnt) ->
 		    R = file:pread(Fd, NewPos, SzSz),
 		    OldPos = Offset + (OldFile - 1)*SzSz,
 		    pwrite_close2(Fd, FileName, OldPos, OldCntBin),
-		    file:close(Fd),
+		    _ = file:close(Fd),
 		    case R of
 			{ok, <<Lost:SzSz/unit:8>>} -> Lost;
 			{ok, _} -> 
@@ -1125,7 +1134,7 @@ write_index_file(read_write, FName, NewFile, OldFile, OldCnt) ->
 		    end;
 		true -> 	
 		    pwrite_close2(Fd, FileName, NewPos, OldCntBin),
-		    file:close(Fd),
+		    _ = file:close(Fd),
 		    0
 	    end;
 	E -> 
@@ -1137,7 +1146,7 @@ to_8_bytes(<<N:32,T/binary>>, NT, FileName, Fd) ->
 to_8_bytes(B, NT, _FileName, _Fd) when byte_size(B) =:= 0 ->
     NT;
 to_8_bytes(_B, _NT, FileName, Fd) ->
-    file:close(Fd),
+    _ = file:close(Fd),
     throw({error, {invalid_index_file, FileName}}).
 
 %% -> ok | throw(FileError)
@@ -1147,7 +1156,7 @@ index_file_trunc(FName, N) ->
 	{ok, Fd} ->
 	    case file:read(Fd, 6) of
 		eof ->
-		    file:close(Fd),
+		    _ = file:close(Fd),
 		    ok;
 		{ok, <<0, 0:32, Version>>} when Version =:= ?VERSION ->
 		    truncate_index_file(Fd, FileName, 10, 8, N);
@@ -1166,10 +1175,10 @@ truncate_index_file(Fd, FileName, Offset, N, SzSz) ->
     Pos = Offset + N*SzSz,
     case Pos > file_size(FileName) of
 	true ->
-	    file:close(Fd);
+	    ok = file:close(Fd);
 	false ->
 	    truncate_at_close2(Fd, FileName, {bof, Pos}),
-	    file:close(Fd)
+	    ok = file:close(Fd)
     end,
     ok.
 	    
@@ -1412,7 +1421,8 @@ fwrite(#cache{c = []} = FdC, _FN, B, Size) ->
             ok;
         _ -> 
             put(write_cache_timer_is_running, true),
-            erlang:send_after(?TIMEOUT, self(), {self(), write_cache})
+            erlang:send_after(?TIMEOUT, self(), {self(), write_cache}),
+            ok
     end,
     {ok, FdC#cache{sz = Size, c = B}};
 fwrite(#cache{sz = Sz, c = C} = FdC, _FN, B, Size) when Sz < ?MAX ->
@@ -1511,7 +1521,7 @@ position_close2(Fd, FileName, Pos) ->
     end.
 	    
 truncate_at_close2(Fd, FileName, Pos) ->
-    position_close2(Fd, FileName, Pos),
+    {ok, _} = position_close2(Fd, FileName, Pos),
     case file:truncate(Fd) of
 	ok    -> ok;
 	Error -> file_error_close(Fd, FileName, Error)
@@ -1519,7 +1529,7 @@ truncate_at_close2(Fd, FileName, Pos) ->
 
 fclose(#cache{fd = Fd, c = C}, FileName) ->
     %% The cache is empty if the file was opened in read_only mode.
-    write_cache_close(Fd, FileName, C),
+    _ = write_cache_close(Fd, FileName, C),
     file:close(Fd).
 
 %% -> {Reply, #cache{}}; Reply = ok | Error
@@ -1549,5 +1559,5 @@ file_error(FileName, {error, Error}) ->
 -spec file_error_close(file:fd(), file:filename(), {'error', file:posix()}) -> no_return().
 
 file_error_close(Fd, FileName, {error, Error}) ->
-    file:close(Fd),
+    _ = file:close(Fd),
     throw({error, {file_error, FileName, Error}}).
diff --git a/lib/kernel/src/disk_log_server.erl b/lib/kernel/src/disk_log_server.erl
index 8894ed87e8..684ea5b5db 100644
--- a/lib/kernel/src/disk_log_server.erl
+++ b/lib/kernel/src/disk_log_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -83,8 +83,8 @@ accessible_logs() ->
 
 init([]) ->
     process_flag(trap_exit, true),
-    ets:new(?DISK_LOG_NAME_TABLE, [named_table, set]),
-    ets:new(?DISK_LOG_PID_TABLE, [named_table, set]),
+    _ = ets:new(?DISK_LOG_NAME_TABLE, [named_table, set]),
+    _= ets:new(?DISK_LOG_PID_TABLE, [named_table, set]),
     {ok, #state{}}.
 
 handle_call({open, W, A}, From, State) ->
@@ -159,15 +159,25 @@ ensure_started() ->
 	undefined ->
 	    LogSup = {disk_log_sup, {disk_log_sup, start_link, []}, permanent,
 		      1000, supervisor, [disk_log_sup]},
-	    supervisor:start_child(kernel_safe_sup, LogSup),
+	    {ok, _} = ensure_child_started(kernel_safe_sup, LogSup),
 	    LogServer = {disk_log_server,
 			 {disk_log_server, start_link, []},
 			 permanent, 2000, worker, [disk_log_server]},
-	    supervisor:start_child(kernel_safe_sup, LogServer),
+	    {ok, _} = ensure_child_started(kernel_safe_sup, LogServer),
 	    ok;
 	_ -> ok
     end.
 
+ensure_child_started(Sup,Child) ->
+    case supervisor:start_child(Sup, Child) of
+	{ok,Pid} ->
+	    {ok,Pid};
+	{error,{already_started,Pid}} ->
+	    {ok,Pid};
+	Error ->
+	    Error
+    end.
+
 open([{Req, From} | L], State) ->
     State2 = case do_open(Req, From, State) of
                  {pending, State1} -> 
diff --git a/lib/kernel/src/dist_ac.erl b/lib/kernel/src/dist_ac.erl
index 5c62aa31e9..98b9e20007 100644
--- a/lib/kernel/src/dist_ac.erl
+++ b/lib/kernel/src/dist_ac.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -321,7 +321,7 @@ handle_call({takeover_application, AppName, RestartType}, From, S) ->
     case keysearch(AppName, #appl.name, Appls) of
 	{value, Appl} when element(1, Appl#appl.id) =:= distributed ->
 	    {distributed, Node} = Appl#appl.id,
-	    ac_takeover(req, AppName, Node, RestartType),
+	    _ = ac_takeover(req, AppName, Node, RestartType),
 	    NAppl = Appl#appl{id = takeover},
 	    NAppls = keyreplace(AppName, #appl.name, Appls, NAppl),
 	    TR = S#state.t_reqs,
@@ -341,10 +341,10 @@ handle_call({permit_application, AppName, Bool, LockId, StartInfo}, From, S) ->
 	    %% here, but we have to be backwards-compatible.
 	    case application_controller:get_loaded(AppName) of
 		{true, _} when not Bool ->
-		    ac_stop_it(AppName),
+		    _ = ac_stop_it(AppName),
 		    {reply, ok, S};
 		{true, _} when Bool ->
-		    ac_start_it(req, AppName),
+		    _ = ac_start_it(req, AppName),
 		    {reply, ok, S};
 		false ->
 		    {reply, {error, {not_loaded, AppName}}, S}
@@ -533,7 +533,7 @@ handle_info({dist_ac_app_started, Node, Name, Res}, S) ->
 			  %% Another node started appl. Update appl list.
 			  {distributed, Node}
 		  end,
-	    ac_started(req, Name, Node),
+	    _ = ac_started(req, Name, Node),
 	    NAppl = Appl#appl{id = NId},
 	    NAppls = keyreplace(Name, #appl.name, Appls, NAppl),
 	    TmpWeights = keydelete_all(Name, 1, S#state.tmp_weights),
@@ -622,7 +622,7 @@ handle_info({nodedown, Node}, S) ->
 			    true ->
 				{true, Appl#appl{id = {failover, Node}}};
 			    false -> 
-				ac_not_running(Appl#appl.name),
+				_ = ac_not_running(Appl#appl.name),
 				{true, Appl#appl{id = undefined}}
 			end;
 		   (_) ->
@@ -656,7 +656,8 @@ handle_info({dist_ac_app_loaded, Node, Name, HisNodes, Permission, HeKnowsMe},
 			    %% he's a new node connecting to us.
 			    Msg = {dist_ac_app_loaded, node(), Name,
 				   Nodes, dist_is_runnable(Appls, Name), true},
-			    {?DIST_AC, Node} ! Msg;
+			    {?DIST_AC, Node} ! Msg,
+                            ok;
 			true ->
 			    ok
 		    end,
@@ -813,27 +814,27 @@ start_distributed(Appl, Name, Nodes, PermittedNodes, S, Type) ->
 	{ok, Node} when Node =:= node() ->
 	    case Appl#appl.id of
 		{failover, FoNode} when Type =:= req ->
-		    ac_failover(Name, FoNode, undefined);
+		    _ = ac_failover(Name, FoNode, undefined);
 		{distributed, Node2} when Type =:= req ->
-		    ac_takeover(req, Name, Node2, undefined);
+		    _ = ac_takeover(req, Name, Node2, undefined);
 		_ when Type =:= reply ->
 		    case lists:keysearch(Name, 2, S#state.remote_started) of
 			{value, {Node3, _}} ->
-			    ac_takeover(reply, Name, Node3, undefined);
+			    _ = ac_takeover(reply, Name, Node3, undefined);
 			_ ->
-			    ac_start_it(Type, Name)
+			    _ = ac_start_it(Type, Name)
 		    end;
 		_ ->
-		    ac_start_it(Type, Name)
+		    _ = ac_start_it(Type, Name)
 	    end,
 	    {run_waiting, true};
 	{already_started, Node} ->
-	    ac_started(Type, Name, Node),
+	    _ = ac_started(Type, Name, Node),
 	    {{distributed, Node}, false};
 	{ok, Node} ->
 	    case keysearch(Name, #appl.name, S#state.appls) of
 		{value, #appl{id = {distributed, Node}}} ->
-		    ac_started(Type, Name, Node),
+		    _ = ac_started(Type, Name, Node),
 		    {{distributed, Node}, false};
 		_ ->
 		    wait_dist_start(Node, Appl, Name, Nodes,
@@ -842,7 +843,7 @@ start_distributed(Appl, Name, Nodes, PermittedNodes, S, Type) ->
 	not_started ->
 	    wait_dist_start2(Appl, Name, Nodes, PermittedNodes, S, Type);
 	no_permission ->
-	    ac_not_started(Type, Name),
+	    _ = ac_not_started(Type, Name),
 	    {undefined, false}
     end.
 
@@ -850,11 +851,11 @@ wait_dist_start(Node, Appl, Name, Nodes, PermittedNodes, S, Type) ->
     monitor_node(Node, true),
     receive
 	{dist_ac_app_started, Node, Name, ok} ->
-	    ac_started(Type, Name, Node),
+	    _ = ac_started(Type, Name, Node),
 	    monitor_node(Node, false),
 	    {{distributed, Node}, false};
 	{dist_ac_app_started, Node, Name, {error, R}} ->
-	    ac_error(Type, Name, {Node, R}),
+	    _ = ac_error(Type, Name, {Node, R}),
 	    monitor_node(Node, false),
 	    {Appl#appl.id, false};
 	{dist_ac_weight, Name, _Weigth, Node} ->
@@ -883,10 +884,10 @@ wait_dist_start(Node, Appl, Name, Nodes, PermittedNodes, S, Type) ->
 wait_dist_start2(Appl, Name, Nodes, PermittedNodes, S, Type) ->
     receive
 	{dist_ac_app_started, Node, Name, ok} ->
-	    ac_started(Type, Name, Node),
+	    _ = ac_started(Type, Name, Node),
 	    {{distributed, Node}, false};
 	{dist_ac_app_started, Node, Name, {error, R}} ->
-	    ac_error(Type, Name, {Node, R}),
+	    _ = ac_error(Type, Name, {Node, R}),
 	    {Appl#appl.id, false};
 	{nodedown, Node} ->
 	    %% A node went down, try to start the app again - there may not
@@ -974,7 +975,7 @@ permit(false, {value, _}, AppName, From, S, _LockId) ->
     case dist_get_runnable_nodes(S#state.appls, AppName) of
 	[] ->
 	    %% There is no runnable node; stop application
-	    ac_stop_it(AppName),
+	    _ = ac_stop_it(AppName),
 	    SReqs = [{AppName, From} | S#state.s_reqs],
 	    {noreply, S#state{s_reqs = SReqs}};
 	Nodes ->
@@ -1155,7 +1156,8 @@ send_nodes(Nodes, Msg) ->
 	    end, FlatNodes).
 
 send_after(Time, Msg) when is_integer(Time), Time >= 0 ->
-    spawn_link(?MODULE, send_timeout, [self(), Time, Msg]);
+    _Pid = spawn_link(?MODULE, send_timeout, [self(), Time, Msg]),
+    ok;
 send_after(_,_) -> % infinity
     ok.
 
@@ -1305,7 +1307,7 @@ check_waiting([{From, AppName, false, Nodes} | Reqs],
 	      S, Node, Appls, Res, SReqs) ->
     case lists:delete(Node, Nodes) of
 	[] ->
-	    ac_stop_it(AppName),
+	    _ = ac_stop_it(AppName),
 	    NSReqs = [{AppName, From} | SReqs],
 	    check_waiting(Reqs, Node, S, Appls, Res, NSReqs);
 	NNodes ->
diff --git a/lib/kernel/src/erl_boot_server.erl b/lib/kernel/src/erl_boot_server.erl
index 0d68d3e198..33f1b96f8d 100644
--- a/lib/kernel/src/erl_boot_server.erl
+++ b/lib/kernel/src/erl_boot_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -191,7 +191,7 @@ init(Slaves) ->
     {ok, UPort} = inet:port(U),
     Ref = make_ref(),
     Pid = proc_lib:spawn_link(?MODULE, boot_init, [Ref]),
-    gen_tcp:controlling_process(L, Pid),
+    ok = gen_tcp:controlling_process(L, Pid),
     Pid ! {Ref, L},
     %% We trap exit inorder to restart boot_init and udp_port 
     process_flag(trap_exit, true),
@@ -233,9 +233,19 @@ handle_info({udp, U, IP, Port, Data}, S0) ->
     %% erlang version as the boot server node
     case {Valid,Data,Token} of
 	{true,Token,Token} ->
-	    gen_udp:send(U,IP,Port,[?EBOOT_REPLY,S0#state.priority,
-				    int16(S0#state.listen_port),
-				    S0#state.version]),
+	    case gen_udp:send(U,IP,Port,[?EBOOT_REPLY,S0#state.priority,
+                                         int16(S0#state.listen_port),
+                                         S0#state.version])
+            of
+                ok -> ok;
+                {error, not_owner} ->
+                    error_logger:error_msg("** Illegal boot server connection attempt: "
+				   "not owner of ~w ** ~n", [U]);
+                {error, Reason} ->
+                    Err = file:format_error(Reason),
+                    error_logger:error_msg("** Illegal boot server connection attempt: "
+				   "~w POSIX error ** ~n", [U, Err])
+            end,
 	    {noreply,S0};
 	{false,_,_} ->
 	    error_logger:error_msg("** Illegal boot server connection attempt: "
diff --git a/lib/kernel/src/erl_epmd.erl b/lib/kernel/src/erl_epmd.erl
index 91af49f303..0b97559ec2 100644
--- a/lib/kernel/src/erl_epmd.erl
+++ b/lib/kernel/src/erl_epmd.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1998-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -217,17 +217,23 @@ do_register_node(NodeName, TcpPort) ->
 	    Extra = "",
 	    Elen = length(Extra),
 	    Len = 1+2+1+1+2+2+2+length(Name)+2+Elen,
-	    gen_tcp:send(Socket, [?int16(Len), ?EPMD_ALIVE2_REQ,
-				   ?int16(TcpPort),
-				   $M,
-				   0,
-				   ?int16(epmd_dist_high()),
-				   ?int16(epmd_dist_low()),
-				   ?int16(length(Name)),
-				   Name,
-				   ?int16(Elen),
-				   Extra]),
-	    wait_for_reg_reply(Socket, []);
+            Packet = [?int16(Len), ?EPMD_ALIVE2_REQ,
+                      ?int16(TcpPort),
+                      $M,
+                      0,
+                      ?int16(epmd_dist_high()),
+                      ?int16(epmd_dist_low()),
+                      ?int16(length(Name)),
+                      Name,
+                      ?int16(Elen),
+                      Extra],
+	    case gen_tcp:send(Socket, Packet) of
+                ok ->
+                    wait_for_reg_reply(Socket, []);
+                Error ->
+                    close(Socket),
+                    Error
+            end;
 	Error ->
 	    Error
     end.
@@ -374,7 +380,7 @@ wait_for_port_reply_name(Socket, Len, Sofar) ->
 %	    io:format("data = ~p~n", _Data),
 	    wait_for_port_reply_name(Socket, Len, Sofar);
 	{tcp_closed, Socket} ->
-	    "foobar"
+	    ok
     end.
 		    
 
diff --git a/lib/kernel/src/erts_debug.erl b/lib/kernel/src/erts_debug.erl
index 6654cd9ee7..f7a815882b 100644
--- a/lib/kernel/src/erts_debug.erl
+++ b/lib/kernel/src/erts_debug.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -288,7 +288,7 @@ dff(Name, Fs) when is_list(Name) ->
 	    try
 		dff(F, Fs)
 	    after
-		file:close(F)
+		_ = file:close(F)
 	    end;
 	{error,Reason} ->
 	    {error,{badopen,Reason}}
diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
index 36289053eb..5c0f3b7ceb 100644
--- a/lib/kernel/src/file.erl
+++ b/lib/kernel/src/file.erl
@@ -376,7 +376,7 @@ write_file(Name, Bin, ModeList) when is_list(ModeList) ->
 			ok ->
 			    close(Handle);
 			E1 ->
-			    close(Handle),
+			    _ = close(Handle),
 			    E1
 		    end;
 		E2 ->
@@ -770,7 +770,7 @@ copy_int({SourceName, SourceOpts}, Dest, Length)
 	    case open(Source, [read | SourceOpts]) of
 		{ok, Handle} ->
 		    Result = copy_opened_int(Handle, Dest, Length, 0),
-		    close(Handle),
+		    _ = close(Handle),
 		    Result;
 		{error, _} = Error ->
 		    Error
@@ -786,9 +786,16 @@ copy_int(Source, {DestName, DestOpts}, Length)
 	Dest ->
 	    case open(Dest, [write | DestOpts]) of
 		{ok, Handle} ->
-		    Result = copy_opened_int(Source, Handle, Length, 0),
-		    close(Handle),
-		    Result;
+                    case copy_opened_int(Source, Handle, Length, 0) of
+                        {ok, _} = OK ->
+                            case close(Handle) of
+                                ok -> OK;
+                                Error -> Error
+                            end;
+                        Error ->
+                            _ = close(Handle),
+                            Error
+                    end;
 		{error, _} = Error ->
 		    Error
 	    end
@@ -957,7 +964,7 @@ consult(File) ->
     case open(File, [read]) of
 	{ok, Fd} ->
 	    R = consult_stream(Fd),
-	    close(Fd),
+	    _ = close(Fd),
 	    R;
 	Error ->
 	    Error
@@ -977,10 +984,10 @@ path_consult(Path, File) ->
 	{ok, Fd, Full} ->
 	    case consult_stream(Fd) of
 		{ok, List} ->
-		    close(Fd),
+		    _ = close(Fd),
 		    {ok, List, Full};
 		E1 ->
-		    close(Fd),
+		    _ = close(Fd),
 		    E1
 	    end;
 	E2 ->
@@ -1005,7 +1012,7 @@ eval(File, Bs) ->
     case open(File, [read]) of
 	{ok, Fd} ->
 	    R = eval_stream(Fd, ignore, Bs),
-	    close(Fd),
+	    _ = close(Fd),
 	    R;
 	Error ->
 	    Error
@@ -1035,10 +1042,10 @@ path_eval(Path, File, Bs) ->
 	{ok, Fd, Full} ->
 	    case eval_stream(Fd, ignore, Bs) of
 		ok ->
-		    close(Fd),
+		    _ = close(Fd),
 		    {ok, Full};
 		E1 ->
-		    close(Fd),
+		    _ = close(Fd),
 		    E1
 	    end;
 	E2 ->
@@ -1065,7 +1072,7 @@ script(File, Bs) ->
     case open(File, [read]) of
 	{ok, Fd} ->
 	    R = eval_stream(Fd, return, Bs),
-	    close(Fd),
+	    _ = close(Fd),
 	    R;
 	Error ->
 	    Error
@@ -1098,10 +1105,10 @@ path_script(Path, File, Bs) ->
 	{ok,Fd,Full} ->
 	    case eval_stream(Fd, return, Bs) of
 		{ok,R} ->
-		    close(Fd),
+		    _ = close(Fd),
 		    {ok, R, Full};
 		E1 ->
-		    close(Fd),
+		    _ = close(Fd),
 		    E1
 	    end;
 	E2 ->
@@ -1247,7 +1254,7 @@ sendfile(Filename, Sock)  ->
 	    {error, Reason};
 	{ok, Fd} ->
 	    Res = sendfile(Fd, Sock, 0, 0, []),
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    Res
     end.
 
@@ -1298,7 +1305,7 @@ sendfile_fallback(File, Sock, Offset, Bytes, ChunkSize) ->
     {ok, CurrPos} = file:position(File, {cur, 0}),
     {ok, _NewPos} = file:position(File, {bof, Offset}),
     Res = sendfile_fallback_int(File, Sock, Bytes, ChunkSize, 0),
-    file:position(File, {bof, CurrPos}),
+    _ = file:position(File, {bof, CurrPos}),
     Res.
 
 
diff --git a/lib/kernel/src/file_io_server.erl b/lib/kernel/src/file_io_server.erl
index 07fb55f390..0e9ff5bc0f 100644
--- a/lib/kernel/src/file_io_server.erl
+++ b/lib/kernel/src/file_io_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2000-2012. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -162,29 +162,29 @@ server_loop(#state{mref = Mref} = State) ->
 	{file_request, From, ReplyAs, Request} when is_pid(From) ->
 	    case file_request(Request, State) of
 		{reply, Reply, NewState} ->
-		    file_reply(From, ReplyAs, Reply),
+		    _ = file_reply(From, ReplyAs, Reply),
 		    server_loop(NewState);
 		{error, Reply, NewState} ->
 		    %% error is the same as reply, except that
 		    %% it breaks the io_request_loop further down
-		    file_reply(From, ReplyAs, Reply),
+		    _ = file_reply(From, ReplyAs, Reply),
 		    server_loop(NewState);
 		{stop, Reason, Reply, _NewState} ->
-		    file_reply(From, ReplyAs, Reply),
+		    _ = file_reply(From, ReplyAs, Reply),
 		    exit(Reason)
 	    end;
 	{io_request, From, ReplyAs, Request} when is_pid(From) ->
 	    case io_request(Request, State) of
 		{reply, Reply, NewState} ->
-		    io_reply(From, ReplyAs, Reply),
+		    _ = io_reply(From, ReplyAs, Reply),
 		    server_loop(NewState);
 		{error, Reply, NewState} ->
 		    %% error is the same as reply, except that
 		    %% it breaks the io_request_loop further down
-		    io_reply(From, ReplyAs, Reply),
+		    _ = io_reply(From, ReplyAs, Reply),
 		    server_loop(NewState);
 		{stop, Reason, Reply, _NewState} ->
-		    io_reply(From, ReplyAs, Reply),
+		    _ = io_reply(From, ReplyAs, Reply),
 		    exit(Reason)
 	    end;
 	{'DOWN', Mref, _, _, Reason} ->
diff --git a/lib/kernel/src/file_server.erl b/lib/kernel/src/file_server.erl
index d036dbb516..eabf0401a3 100644
--- a/lib/kernel/src/file_server.erl
+++ b/lib/kernel/src/file_server.erl
@@ -78,7 +78,8 @@ init([]) ->
     process_flag(trap_exit, true),
     case ?PRIM_FILE:start() of
 	{ok, Handle} ->
-	    ets:new(?FILE_IO_SERVER_TABLE, [named_table]),
+	    ?FILE_IO_SERVER_TABLE =
+                ets:new(?FILE_IO_SERVER_TABLE, [named_table]),
 	    {ok, Handle};
 	{error, Reason} ->
 	    {stop, Reason}
diff --git a/lib/kernel/src/gen_sctp.erl b/lib/kernel/src/gen_sctp.erl
index 74ad192802..81c9fbe55f 100644
--- a/lib/kernel/src/gen_sctp.erl
+++ b/lib/kernel/src/gen_sctp.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2007-2012. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -270,7 +270,7 @@ do_connect(S, Addr, Port, Opts, Timeout, ConnWait) when is_port(S), is_list(Opts
 				    Mod:connect(S, IP, Port, Opts, ConnectTimer);
 				Error -> Error
 			    after
-				inet:stop_timer(Timer)
+				_ = inet:stop_timer(Timer)
 			    end
 		    catch
 			error:badarg ->
diff --git a/lib/kernel/src/gen_tcp.erl b/lib/kernel/src/gen_tcp.erl
index a98ed4c238..96026aa428 100644
--- a/lib/kernel/src/gen_tcp.erl
+++ b/lib/kernel/src/gen_tcp.erl
@@ -139,7 +139,7 @@ connect(Address, Port, Opts) ->
 connect(Address, Port, Opts, Time) ->
     Timer = inet:start_timer(Time),
     Res = (catch connect1(Address,Port,Opts,Timer)),
-    inet:stop_timer(Timer),
+    _ = inet:stop_timer(Timer),
     case Res of
 	{ok,S} -> {ok,S};
 	{error, einval} -> exit(badarg);
diff --git a/lib/kernel/src/global.erl b/lib/kernel/src/global.erl
index b24a9d5eac..3f672c099b 100644
--- a/lib/kernel/src/global.erl
+++ b/lib/kernel/src/global.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -2069,7 +2069,8 @@ random_sleep(Times) ->
     case get(random_seed) of
 	undefined ->
 	    {A1, A2, A3} = now(),
-	    random:seed(A1, A2, A3 + erlang:phash(node(), 100000));
+	    random:seed(A1, A2, A3 + erlang:phash(node(), 100000)),
+            ok;
 	_ -> ok
     end,
     %% First time 1/4 seconds, then doubling each time up to 8 seconds max.
diff --git a/lib/kernel/src/global_group.erl b/lib/kernel/src/global_group.erl
index 025a9b8a5b..da8b573749 100644
--- a/lib/kernel/src/global_group.erl
+++ b/lib/kernel/src/global_group.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1998-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -1149,9 +1149,14 @@ do_unlink(Pid, State) ->
 %%%====================================================================================
 %%% Send a nodeup/down messages to monitoring Pids in the own global group.
 %%%====================================================================================
-send_monitor([P|T], M, no_conf) -> safesend_nc(P, M), send_monitor(T, M, no_conf);
-send_monitor([P|T], M, SyncState) -> safesend(P, M), send_monitor(T, M, SyncState);
-send_monitor([], _, _) -> ok.
+send_monitor([P|T], M, no_conf) ->
+    _ = safesend_nc(P, M),
+    send_monitor(T, M, no_conf);
+send_monitor([P|T], M, SyncState) ->
+    _ = safesend(P, M),
+    send_monitor(T, M, SyncState);
+send_monitor([], _, _) ->
+    ok.
 
 safesend(Name, {Msg, Node}) when is_atom(Name) ->
     case lists:member(Node, get_own_nodes()) of
diff --git a/lib/kernel/src/group.erl b/lib/kernel/src/group.erl
index ff835e1047..b36dbf33dd 100644
--- a/lib/kernel/src/group.erl
+++ b/lib/kernel/src/group.erl
@@ -309,15 +309,17 @@ io_requests([], Stat, _) ->
 %%  The ACK contains the return value.
 
 io_reply(From, ReplyAs, Reply) ->
-    From ! {io_reply,ReplyAs,Reply}.
+    From ! {io_reply,ReplyAs,Reply},
+    ok.
 
 %% send_drv(Drv, Message)
 %% send_drv_reqs(Drv, Requests)
 
 send_drv(Drv, Msg) ->
-    Drv ! {self(),Msg}.
+    Drv ! {self(),Msg},
+    ok.
 
-send_drv_reqs(_Drv, []) -> [];
+send_drv_reqs(_Drv, []) -> ok;
 send_drv_reqs(Drv, Rs) ->
     send_drv(Drv, {requests,Rs}).
 
diff --git a/lib/kernel/src/heart.erl b/lib/kernel/src/heart.erl
index 87cb9d7f51..aa65c3a474 100644
--- a/lib/kernel/src/heart.erl
+++ b/lib/kernel/src/heart.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -182,11 +182,11 @@ wait_ack(Port) ->
     end.
 
 loop(Parent, Port, Cmd) ->
-    send_heart_beat(Port),
+    _ = send_heart_beat(Port),
     receive
 	{From, set_cmd, NewCmd} when length(NewCmd) < 2047 ->
-	    send_heart_cmd(Port, NewCmd),
-	    wait_ack(Port),
+	    _ = send_heart_cmd(Port, NewCmd),
+	    _ = wait_ack(Port),
 	    From ! {heart, ok},
 	    loop(Parent, Port, NewCmd);
 	{From, set_cmd, NewCmd} ->
@@ -194,8 +194,8 @@ loop(Parent, Port, Cmd) ->
 	    loop(Parent, Port, Cmd);
 	{From, clear_cmd} ->
 	    From ! {heart, ok},
-	    send_heart_cmd(Port, ""),
-	    wait_ack(Port),
+	    _ = send_heart_cmd(Port, ""),
+	    _ = wait_ack(Port),
 	    loop(Parent, Port, "");
 	{From, get_cmd} ->
 	    From ! {heart, get_heart_cmd(Port)},
@@ -222,7 +222,7 @@ loop(Parent, Port, Cmd) ->
 -spec no_reboot_shutdown(port()) -> no_return().
 
 no_reboot_shutdown(Port) ->
-    send_shutdown(Port),
+    _ = send_shutdown(Port),
     receive
 	{'EXIT', Port, Reason} when Reason =/= badsig ->
 	    exit(normal)
@@ -232,10 +232,10 @@ do_cycle_port_program(Caller, Parent, Port, Cmd) ->
     unregister(?HEART_PORT_NAME),
     case catch start_portprogram() of
 	{ok, NewPort} ->
-	    send_shutdown(Port),
+	    _ = send_shutdown(Port),
 	    receive
 		{'EXIT', Port, _Reason} ->
-		    send_heart_cmd(NewPort, Cmd),
+		    _ = send_heart_cmd(NewPort, Cmd),
 		    Caller ! {heart, ok},
 		    loop(Parent, NewPort, Cmd)
 	    after
@@ -243,7 +243,7 @@ do_cycle_port_program(Caller, Parent, Port, Cmd) ->
 		    %% Huh! Two heart port programs running...
 		    %% well, the old one has to be sick not to respond
 		    %% so we'll settle for the new one...
-		    send_heart_cmd(NewPort, Cmd),
+		    _ = send_heart_cmd(NewPort, Cmd),
 		    Caller ! {heart, {error, stop_error}},
 		    loop(Parent, NewPort, Cmd)
 	    end;
diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl
index 9670271b2e..b0f4adce2c 100644
--- a/lib/kernel/src/inet.erl
+++ b/lib/kernel/src/inet.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -389,7 +389,7 @@ gethostbyname(Name,Family) ->
 gethostbyname(Name,Family,Timeout) ->
     Timer = start_timer(Timeout),
     Res = gethostbyname_tm(Name,Family,Timer),
-    stop_timer(Timer),
+    _ = stop_timer(Timer),
     Res.
 
 gethostbyname_tm(Name,Family,Timer) ->
@@ -420,7 +420,7 @@ gethostbyaddr(Address) ->
 gethostbyaddr(Address,Timeout) ->
     Timer = start_timer(Timeout),    
     Res = gethostbyaddr_tm(Address, Timer),
-    stop_timer(Timer),
+    _ = stop_timer(Timer),
     Res.
 
 gethostbyaddr_tm(Address,Timer) ->
@@ -475,7 +475,7 @@ getaddr(Address, Family) ->
 getaddr(Address, Family, Timeout) ->
     Timer = start_timer(Timeout),
     Res = getaddr_tm(Address, Family, Timer),
-    stop_timer(Timer),
+    _ = stop_timer(Timer),
     Res.
 
 getaddr_tm(Address, Family, Timer) ->
@@ -501,7 +501,7 @@ getaddrs(Address, Family) ->
 getaddrs(Address, Family, Timeout) ->
     Timer = start_timer(Timeout),
     Res = getaddrs_tm(Address, Family, Timer),
-    stop_timer(Timer),
+    _ = stop_timer(Timer),
     Res.
 
 -spec getservbyport(Port :: port_number(), Protocol :: atom() | string()) ->
diff --git a/lib/kernel/src/inet6_tcp_dist.erl b/lib/kernel/src/inet6_tcp_dist.erl
index 2cb0e10c87..459fdc2ad5 100644
--- a/lib/kernel/src/inet6_tcp_dist.erl
+++ b/lib/kernel/src/inet6_tcp_dist.erl
@@ -92,7 +92,7 @@ accept_loop(Kernel, Listen) ->
     case inet6_tcp:accept(Listen) of
         {ok, Socket} ->
             Kernel ! {accept,self(),Socket,inet6,tcp},
-            controller(Kernel, Socket),
+            _ = controller(Kernel, Socket),
             accept_loop(Kernel, Listen);
         Error ->
             exit(Error)
diff --git a/lib/kernel/src/inet_db.erl b/lib/kernel/src/inet_db.erl
index d4749b9756..8a2994579b 100644
--- a/lib/kernel/src/inet_db.erl
+++ b/lib/kernel/src/inet_db.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -1112,7 +1112,7 @@ handle_call(Request, From, #state{db=Db}=State) ->
 	{set_cache_refresh, Time} when is_integer(Time), Time > 0 ->
 	    Time1 = ((Time+999) div 1000)*1000, %% round up
 	    ets:insert(Db, {cache_refresh_interval, Time1}),
-	    stop_timer(State#state.cache_timer),
+	    _ = stop_timer(State#state.cache_timer),
 	    {reply, ok, State#state{cache_timer = init_timer()}};
 
 	clear_hosts ->
@@ -1126,7 +1126,7 @@ handle_call(Request, From, #state{db=Db}=State) ->
 
 	reset ->
 	    reset_db(Db),
-	    stop_timer(State#state.cache_timer),
+	    _ = stop_timer(State#state.cache_timer),
 	    {reply, ok, State#state{cache_timer = init_timer()}};
 
 	{add_rc_list, List} ->
@@ -1176,7 +1176,7 @@ handle_info(_Info, State) ->
 -spec terminate(term(), state()) -> 'ok'.
 
 terminate(_Reason, State) ->
-    stop_timer(State#state.cache_timer),
+    _ = stop_timer(State#state.cache_timer),
     ok.
 
 %%%----------------------------------------------------------------------
@@ -1233,7 +1233,7 @@ do_add_host(Byname, Byaddr, Names, Type, IP) ->
     ok.
 
 do_del_host(Byname, Byaddr, IP) ->
-    [ets:delete_object(Byname, NIP) || NIP <- ets:lookup(Byaddr, IP)],
+    _ = [ets:delete_object(Byname, NIP) || NIP <- ets:lookup(Byaddr, IP)],
     ets:delete(Byaddr, IP),
     ok.
 
diff --git a/lib/kernel/src/inet_gethost_native.erl b/lib/kernel/src/inet_gethost_native.erl
index df866660b4..4320987078 100644
--- a/lib/kernel/src/inet_gethost_native.erl
+++ b/lib/kernel/src/inet_gethost_native.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1998-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -237,7 +237,7 @@ handle_message({Port, {data, Data}}, State = #state{port = Port}) ->
 				       State;
 				   Req ->
 				       lists:foreach(fun({P,R,TR}) ->
-							     ?CANCEL_TIMER(TR),
+							     _= ?CANCEL_TIMER(TR),
 							     P ! {R,
 								  {ok,
 								   BinReply}}
@@ -276,7 +276,7 @@ handle_message({timeout, Pid, RID}, State) ->
 	{last, {LP,LR,_}} ->
 	    LP ! {LR, {error,timeout}},
 	    %% Remove the whole request structure...
-	    pick_request(State, RID),
+	    _ = pick_request(State, RID),
 	    %% Also cancel the request to the port program...
 	    (catch port_command(State#state.port, 
 				<<RID:32,?OP_CANCEL_REQUEST>>))
@@ -517,7 +517,7 @@ do_start(Sup, C) ->
 	{error, {{already_started, Pid}, _Child}} when is_pid(Pid) ->
 	    ok;
 	{error, already_present} ->
-	    supervisor:delete_child(Sup, Child),
+	    _ = supervisor:delete_child(Sup, Child),
 	    do_start(Sup, C)
     end.
 
diff --git a/lib/kernel/src/inet_parse.erl b/lib/kernel/src/inet_parse.erl
index 619c78a6ca..d24bda0c3d 100644
--- a/lib/kernel/src/inet_parse.erl
+++ b/lib/kernel/src/inet_parse.erl
@@ -288,7 +288,7 @@ parse_file(_, File, Fn) ->
     case file:open(File, [read]) of
 	{ok, Fd} ->
 	    Result = parse_fd(File,Fd, 1, Fn, []),
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    Result;
 	Error -> Error
     end.
diff --git a/lib/kernel/src/inet_res.erl b/lib/kernel/src/inet_res.erl
index 59ba408d7a..1a30979126 100644
--- a/lib/kernel/src/inet_res.erl
+++ b/lib/kernel/src/inet_res.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -139,7 +139,7 @@ resolve(Name, Class, Type, Opts, Timeout) ->
 	{ok, Nm} ->
 	    Timer = inet:start_timer(Timeout),
 	    Res = res_query(Nm, Class, Type, Opts, Timer),
-	    inet:stop_timer(Timer),
+	    _ = inet:stop_timer(Timer),
 	    Res;
 	Error ->
 	    Error
@@ -339,7 +339,7 @@ gethostbyaddr(IP) -> gethostbyaddr_tm(IP,false).
 gethostbyaddr(IP,Timeout) ->
     Timer = inet:start_timer(Timeout),
     Res = gethostbyaddr_tm(IP,Timer),
-    inet:stop_timer(Timer),
+    _ = inet:stop_timer(Timer),
     Res.    
 
 gethostbyaddr_tm({A,B,C,D} = IP, Timer) when ?ip(A,B,C,D) ->
@@ -424,7 +424,7 @@ gethostbyname(Name,Family) ->
 gethostbyname(Name,Family,Timeout) ->
     Timer = inet:start_timer(Timeout),    
     Res = gethostbyname_tm(Name,Family,Timer),
-    inet:stop_timer(Timer),
+    _ = inet:stop_timer(Timer),
     Res.
     
 gethostbyname_tm(Name,inet,Timer) ->
@@ -483,7 +483,7 @@ getbyname(Name, Type) ->
 getbyname(Name, Type, Timeout) ->
     Timer = inet:start_timer(Timeout),
     Res = getbyname_tm(Name, Type, Timer),
-    inet:stop_timer(Timer),
+    _ = inet:stop_timer(Timer),
     Res.
 
 getbyname_tm(Name, Type, Timer) when is_list(Name) ->
diff --git a/lib/kernel/src/inet_tcp_dist.erl b/lib/kernel/src/inet_tcp_dist.erl
index 8005eff58c..63f236b069 100644
--- a/lib/kernel/src/inet_tcp_dist.erl
+++ b/lib/kernel/src/inet_tcp_dist.erl
@@ -119,7 +119,7 @@ accept_loop(Kernel, Listen) ->
     case inet_tcp:accept(Listen) of
 	{ok, Socket} ->
 	    Kernel ! {accept,self(),Socket,inet,tcp},
-	    controller(Kernel, Socket),
+	    _ = controller(Kernel, Socket),
 	    accept_loop(Kernel, Listen);
 	Error ->
 	    exit(Error)
diff --git a/lib/kernel/src/net_kernel.erl b/lib/kernel/src/net_kernel.erl
index dd0071b914..0c70e5f125 100644
--- a/lib/kernel/src/net_kernel.erl
+++ b/lib/kernel/src/net_kernel.erl
@@ -320,7 +320,7 @@ passive_connect_monitor(Parent, Node) ->
 		    Parent ! {self(), false};
 		{nodeup,Node,_} ->
 		    monitor_nodes(false,[{node_type,all}]),
-		    erlang:cancel_timer(Tref),
+		    _ = erlang:cancel_timer(Tref),
 		    Parent ! {self(),true}
 	    end
     end.
diff --git a/lib/kernel/src/os.erl b/lib/kernel/src/os.erl
index 742c000cc1..1f96e5c3c0 100644
--- a/lib/kernel/src/os.erl
+++ b/lib/kernel/src/os.erl
@@ -275,8 +275,8 @@ start_port_srv_handle({Ref,Client}) ->
 		error:Reason ->
 		    {Reason,erlang:get_stacktrace()}	    
 	    end,
-    Client ! {Ref,Reply}.
-
+    Client ! {Ref,Reply},
+    ok.
 
 start_port_srv_loop() ->
     receive
@@ -284,7 +284,7 @@ start_port_srv_loop() ->
 				     is_pid(Client) ->
 	    start_port_srv_handle(Request);
 	_Junk ->
-	    ignore
+	    ok
     end,
     start_port_srv_loop().
 
diff --git a/lib/kernel/src/pg2.erl b/lib/kernel/src/pg2.erl
index 1ff10eb303..2cfbcc9189 100644
--- a/lib/kernel/src/pg2.erl
+++ b/lib/kernel/src/pg2.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1997-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -45,7 +45,7 @@ start() ->
 -spec create(Name :: name()) -> 'ok'.
 
 create(Name) ->
-    ensure_started(),
+    _ = ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
         false ->
             global:trans({{?MODULE, Name}, self()},
@@ -60,7 +60,7 @@ create(Name) ->
 -spec delete(Name :: name()) -> 'ok'.
 
 delete(Name) ->
-    ensure_started(),
+    _ = ensure_started(),
     global:trans({{?MODULE, Name}, self()},
                  fun() ->
                          gen_server:multi_call(?MODULE, {delete, Name})
@@ -71,7 +71,7 @@ delete(Name) ->
       when Name :: name().
 
 join(Name, Pid) when is_pid(Pid) ->
-    ensure_started(),
+    _ = ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
         false ->
             {error, {no_such_group, Name}};
@@ -88,7 +88,7 @@ join(Name, Pid) when is_pid(Pid) ->
       when Name :: name().
 
 leave(Name, Pid) when is_pid(Pid) ->
-    ensure_started(),
+    _ = ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
         false ->
             {error, {no_such_group, Name}};
@@ -105,7 +105,7 @@ leave(Name, Pid) when is_pid(Pid) ->
       when Name :: name().
 
 get_members(Name) ->
-    ensure_started(),
+    _ = ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
         true ->
             group_members(Name);
@@ -117,7 +117,7 @@ get_members(Name) ->
       when Name :: name().
 
 get_local_members(Name) ->
-    ensure_started(),
+    _ = ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
         true ->
             local_group_members(Name);
@@ -128,7 +128,7 @@ get_local_members(Name) ->
 -spec which_groups() -> [Name :: name()].
 
 which_groups() ->
-    ensure_started(),
+    _ = ensure_started(),
     all_groups().
 
 -spec get_closest_pid(Name) ->  pid() | {'error', Reason} when
@@ -283,7 +283,7 @@ member_died(Ref) ->
 
 join_group(Name, Pid) ->
     Ref_Pid = {ref, Pid}, 
-    try _ = ets:update_counter(pg2_table, Ref_Pid, {4, +1})
+    try _ = ets:update_counter(pg2_table, Ref_Pid, {4, +1}), true
     catch _:_ ->
             {RPid, Ref} = do_monitor(Pid),
             true = ets:insert(pg2_table, {Ref_Pid, RPid, Ref, 1}),
diff --git a/lib/kernel/src/rpc.erl b/lib/kernel/src/rpc.erl
index 83e0b59cc2..78fec2aa2b 100644
--- a/lib/kernel/src/rpc.erl
+++ b/lib/kernel/src/rpc.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -158,20 +158,20 @@ handle_info({Caller, {reply, Reply}}, S) ->
 	    {noreply, S}
     end;
 handle_info({From, {sbcast, Name, Msg}}, S) ->
-    case catch Name ! Msg of  %% use catch to get the printout
-	{'EXIT', _} ->
-	    From ! {?NAME, node(), {nonexisting_name, Name}};
-	_ -> 
-	    From ! {?NAME, node(), node()}
-    end,
+    _ = case catch Name ! Msg of  %% use catch to get the printout
+            {'EXIT', _} ->
+                From ! {?NAME, node(), {nonexisting_name, Name}};
+            _ ->
+                From ! {?NAME, node(), node()}
+        end,
     {noreply, S};
 handle_info({From, {send, Name, Msg}}, S) ->
-    case catch Name ! {From, Msg} of %% use catch to get the printout
-	{'EXIT', _} ->
-	    From ! {?NAME, node(), {nonexisting_name, Name}};
-	_ ->
-	    ok    %% It's up to Name to respond !!!!!
-    end,
+    _ = case catch Name ! {From, Msg} of %% use catch to get the printout
+            {'EXIT', _} ->
+                From ! {?NAME, node(), {nonexisting_name, Name}};
+            _ ->
+                ok    %% It's up to Name to respond !!!!!
+        end,
     {noreply, S};
 handle_info({From, {call,Mod,Fun,Args,Gleader}}, S) ->
     %% Special for hidden C node's, uugh ...
@@ -423,7 +423,7 @@ abcast(Name, Mess) ->
 abcast([Node|Tail], Name, Mess) ->
     Dest = {Name,Node},
     case catch erlang:send(Dest, Mess, [noconnect]) of
-	noconnect -> spawn(erlang, send, [Dest,Mess]);
+	noconnect -> spawn(erlang, send, [Dest,Mess]), ok;
 	_ -> ok
     end,
     abcast(Tail, Name, Mess);
diff --git a/lib/kernel/src/standard_error.erl b/lib/kernel/src/standard_error.erl
index e41dcd01fc..10cf77e0d4 100644
--- a/lib/kernel/src/standard_error.erl
+++ b/lib/kernel/src/standard_error.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2009-2010. All Rights Reserved.
+%% Copyright Ericsson AB 2009-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -69,7 +69,7 @@ run(P) ->
 server_loop(Port) ->
     receive
 	{io_request,From,ReplyAs,Request} when is_pid(From) ->
-	    do_io_request(Request, From, ReplyAs, Port),
+	    _ = do_io_request(Request, From, ReplyAs, Port),
 	    server_loop(Port);
 	{'EXIT',Port,badsig} ->			% Ignore badsig errors
 	    server_loop(Port);
@@ -175,7 +175,7 @@ io_reply(From, ReplyAs, Reply) ->
 
 %% put_chars
 put_chars(Chars, Port) when is_binary(Chars) ->
-    put_port(Chars, Port),
+    _ = put_port(Chars, Port),
     {ok,ok};
 put_chars(Chars, Port) ->
     case catch list_to_binary(Chars) of
diff --git a/lib/kernel/src/user.erl b/lib/kernel/src/user.erl
index c897d46bc2..40376ef752 100644
--- a/lib/kernel/src/user.erl
+++ b/lib/kernel/src/user.erl
@@ -103,11 +103,11 @@ catch_loop(Port, Shell, Q) ->
 	{unknown_exit,{Shell,Reason},_} ->		 % shell has exited
 	    case Reason of
 		normal ->
-		    put_chars("*** ", Port, []);
+                    put_port(<<"*** ">>, Port);
 		_ ->
-		    put_chars("*** ERROR: ", Port, [])
+                    put_port(<<"*** ERROR: ">>, Port)
 	    end,
-	    put_chars("Shell process terminated! ***\n", Port, []),
+	    put_port(<<"Shell process terminated! ***\n">>, Port),
 	    catch_loop(Port, start_new_shell());
 	{unknown_exit,_,Q1} ->
 	    catch_loop(Port, Shell, Q1);	     
@@ -181,7 +181,7 @@ get_fd_geometry(Port) ->
 do_io_request(Req, From, ReplyAs, Port, Q0) ->
     case io_request(Req, Port, Q0) of
 	{_Status,Reply,Q1} ->
-	    io_reply(From, ReplyAs, Reply),
+	    _ = io_reply(From, ReplyAs, Reply),
 	    Q1;
 	{exit,What} ->
 	    ok = send_port(Port, close),
diff --git a/lib/kernel/src/user_drv.erl b/lib/kernel/src/user_drv.erl
index bb654495d3..6544426a54 100644
--- a/lib/kernel/src/user_drv.erl
+++ b/lib/kernel/src/user_drv.erl
@@ -488,21 +488,19 @@ set_unicode_state(Iport, Bool) ->
 
 %% io_request(Request, InPort, OutPort)
 %% io_requests(Requests, InPort, OutPort)
-
-io_request({put_chars, unicode,Cs}, _Iport, Oport) ->
-    Oport ! {self(),{command,[?OP_PUTC|unicode:characters_to_binary(Cs,utf8)]}};
-io_request({move_rel,N}, _Iport, Oport) ->
-    Oport ! {self(),{command,[?OP_MOVE|put_int16(N, [])]}};
-io_request({insert_chars,unicode,Cs}, _Iport, Oport) ->
-    Oport ! {self(),{command,[?OP_INSC|unicode:characters_to_binary(Cs,utf8)]}};
-io_request({delete_chars,N}, _Iport, Oport) ->
-    Oport ! {self(),{command,[?OP_DELC|put_int16(N, [])]}};
-io_request(beep, _Iport, Oport) ->
-    Oport ! {self(),{command,[?OP_BEEP]}};
-io_request({requests,Rs}, Iport, Oport) ->
-    io_requests(Rs, Iport, Oport);
-io_request(_R, _Iport, _Oport) ->
-    ok.
+%% Note: InPort is unused.
+
+io_request(Request, Iport, Oport) ->
+    try io_command(Request) of
+        Command ->
+            Oport ! {self(),Command},
+            ok
+    catch
+        {requests,Rs} ->
+            io_requests(Rs, Iport, Oport);
+        _ ->
+            ok
+    end.
 
 io_requests([R|Rs], Iport, Oport) ->
     io_request(R, Iport, Oport),
@@ -513,6 +511,19 @@ io_requests([], _Iport, _Oport) ->
 put_int16(N, Tail) ->
     [(N bsr 8)band 255,N band 255|Tail].
 
+io_command({put_chars, unicode,Cs}) ->
+    {command,[?OP_PUTC|unicode:characters_to_binary(Cs,utf8)]};
+io_command({move_rel,N}) ->
+    {command,[?OP_MOVE|put_int16(N, [])]};
+io_command({insert_chars,unicode,Cs}) ->
+    {command,[?OP_INSC|unicode:characters_to_binary(Cs,utf8)]};
+io_command({delete_chars,N}) ->
+    {command,[?OP_DELC|put_int16(N, [])]};
+io_command(beep) ->
+    {command,[?OP_BEEP]};
+io_command(Else) ->
+    throw(Else).
+
 %% gr_new()
 %% gr_get_num(Group, Index)
 %% gr_get_info(Group, Pid)
diff --git a/lib/kernel/src/wrap_log_reader.erl b/lib/kernel/src/wrap_log_reader.erl
index 689269fc28..7e1f4aa07f 100644
--- a/lib/kernel/src/wrap_log_reader.erl
+++ b/lib/kernel/src/wrap_log_reader.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1998-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1998-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -149,7 +149,7 @@ open_int(File, FileNo, FirstFileNo) ->
 		{ok, Head} ->
 		    case disk_log_1:is_head(Head) of
 			no ->
-			    file:close(Fd),
+			    _ = file:close(Fd),
 			    {error, {not_a_log_file, FName}};
 			_ -> % yes or yes_not_closed
 			    case last_mod_time(FName) of
@@ -161,12 +161,12 @@ open_int(File, FileNo, FirstFileNo) ->
 						      first_no = FirstFileNo},
 				    {ok, WR};
 				{error, E} ->
-				    file:close(Fd),
+				    _ = file:close(Fd),
 				    {error, {file_error, FName, E}}
 			    end
 		    end;
 		_Other ->
-		    file:close(Fd),
+		    _ = file:close(Fd),
 		    {error, {not_a_log_file, FName}}
 	    end;
 	_Other ->
@@ -280,7 +280,7 @@ read_next_file(WR, N, NewFileNo, Bad) ->
 		true -> 
 		    case open_int(File, NewFileNo, FirstFileNo) of
 			{ok, NWR} ->
-			    close(WR), %% Now we can safely close the old file.
+			    _ = close(WR), %% Now we can safely close the old file.
 			    chunk(NWR, N, Bad);
 			Error ->
 			    Error
diff --git a/lib/stdlib/src/beam_lib.erl b/lib/stdlib/src/beam_lib.erl
index fe7e0f8e60..7a93fa0f45 100644
--- a/lib/stdlib/src/beam_lib.erl
+++ b/lib/stdlib/src/beam_lib.erl
@@ -904,7 +904,7 @@ call_crypto_server(Req) ->
     end.
 
 call_crypto_server_1(Req) ->
-    gen_server:start({local,?CRYPTO_KEY_SERVER}, ?MODULE, [], []),
+    {ok, _} = gen_server:start({local,?CRYPTO_KEY_SERVER}, ?MODULE, [], []),
     erlang:yield(),
     call_crypto_server(Req).
 
diff --git a/lib/stdlib/src/c.erl b/lib/stdlib/src/c.erl
index 91d317489c..56d435d5d7 100644
--- a/lib/stdlib/src/c.erl
+++ b/lib/stdlib/src/c.erl
@@ -694,7 +694,7 @@ pwd() ->
       Dir :: file:name().
 
 cd(Dir) ->
-    file:set_cwd(Dir),
+    _ = file:set_cwd(Dir),
     pwd().
 
 %% ls()
diff --git a/lib/stdlib/src/dets.erl b/lib/stdlib/src/dets.erl
index 50812cc532..d743467e97 100644
--- a/lib/stdlib/src/dets.erl
+++ b/lib/stdlib/src/dets.erl
@@ -469,7 +469,7 @@ is_compatible_bchunk_format(Tab, Term) ->
 is_dets_file(FileName) ->
     case catch read_file_header(FileName, read, false) of
 	{ok, Fd, FH} ->
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    FH#fileheader.cookie =:= ?MAGIC;
 	{error, {tooshort, _}} ->
 	    false;
@@ -1384,7 +1384,8 @@ do_apply_op(Op, From, Head, N) ->
             end,
             if
                 From =/= self() ->
-                    From ! {self(), {error, {dets_bug, Name, Op, Bad}}};
+                    From ! {self(), {error, {dets_bug, Name, Op, Bad}}},
+                    ok;
                 true -> % auto_save | may_grow | {delayed_write, _}
                     ok
             end,
@@ -1634,7 +1635,8 @@ start_auto_save_timer(Head) when Head#head.auto_save =:= infinity ->
     ok;
 start_auto_save_timer(Head) ->
     Millis = Head#head.auto_save,
-    erlang:send_after(Millis, self(), ?DETS_CALL(self(), auto_save)).
+    _Ref = erlang:send_after(Millis, self(), ?DETS_CALL(self(), auto_save)),
+    ok.
 
 %% Version 9: Peek the message queue and try to evaluate several
 %% lookup requests in parallel. Evalute delete_object, delete and
@@ -1683,7 +1685,7 @@ stream_end(Head, Pids0, C, N, Next) ->
 	    %%  replies to delete and insert requests even if the
 	    %%  latter requests were made before the lookup requests,
 	    %%  which can be confusing.)
-	    lookup_replies(Found),
+	    _ = lookup_replies(Found),
 	    stream_end1(Pids0, Next, N, C, Head1, PwriteList);
 	Head1 when is_record(Head1, head) ->
 	    stream_end2(Pids0, Pids0, Next, N, C, Head1, ok);	    
@@ -1733,7 +1735,7 @@ lookup_replies(Q) ->
 lookup_replies(P, O, []) ->
     lookup_reply(P, O);
 lookup_replies(P, O, [{P2,O2} | L]) ->
-    lookup_reply(P, O),
+    _ = lookup_reply(P, O),
     lookup_replies(P2, lists:append(O2), L).
 
 %% If a list of Pid then op was {member, Key}. Inlined.
@@ -1790,12 +1792,15 @@ fclose(Head) ->
     {Head1, Res} = perform_save(Head, false),
     case Head1#head.ram_file of
 	true -> 
-	    ignore;
+            Res;
 	false -> 
             dets_utils:stop_disk_map(),
-	    file:close(Head1#head.fptr)
-    end,
-    Res.
+	    Res2 = file:close(Head1#head.fptr),
+            if
+                Res2 =:= ok -> Res;
+                true -> Res2
+            end
+    end.
 
 %% -> {NewHead, Res}
 perform_save(Head, DoSync) when Head#head.update_mode =:= dirty;
@@ -2002,7 +2007,7 @@ remove_fix(Head, Pid, How) ->
     end.
 
 do_stop(Head) ->
-    unlink_fixing_procs(Head),
+    _NewHead = unlink_fixing_procs(Head),
     fclose(Head).
 
 unlink_fixing_procs(Head) ->
@@ -2010,7 +2015,7 @@ unlink_fixing_procs(Head) ->
 	false ->
 	    Head;
 	{_, Counters} ->
-	    lists:map(fun({Pid, _Counter}) -> unlink(Pid) end, Counters),
+	    lists:foreach(fun({Pid, _Counter}) -> unlink(Pid) end, Counters),
 	    Head#head{fixed = false, 
 		      freelists = dets_utils:get_freelists(Head)}
     end.
@@ -2021,8 +2026,9 @@ check_growth(Head) ->
     NoThings = no_things(Head),
     if
 	NoThings > Head#head.next ->
-	    erlang:send_after(200, self(), 
-			      ?DETS_CALL(self(), may_grow)); % Catch up.
+	    _Ref = erlang:send_after
+                     (200, self(), ?DETS_CALL(self(), may_grow)), % Catch up.
+            ok;
 	true ->
 	    ok
     end.
@@ -2123,7 +2129,7 @@ do_open_file([Fname, Verbose], Parent, Server, Ref) ->
 do_open_file([Tab, OpenArgs, Verb], Parent, Server, Ref) ->
     case catch fopen3(Tab, OpenArgs) of
 	{error, {tooshort, _}} ->
-	    file:delete(OpenArgs#open_args.file),
+	    _ = file:delete(OpenArgs#open_args.file),
 	    do_open_file([Tab, OpenArgs, Verb], Parent, Server, Ref);
 	{error, _Reason} = Error ->
 	    err(Error);
@@ -2671,11 +2677,11 @@ fopen_init_file(Tab, OpenArgs) ->
     case catch Mod:initiate_file(Fd, Tab, Fname, Type, Kp, MinSlots, MaxSlots,
 				 Ram, CacheSz, Auto, true) of
 	{error, Reason} when Ram ->
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    throw({error, Reason});
 	{error, Reason} ->
-	    file:close(Fd),
-	    file:delete(Fname),
+	    _ = file:close(Fd),
+	    _ = file:delete(Fname),
 	    throw({error, Reason});
 	{ok, Head} ->
 	    start_auto_save_timer(Head),
@@ -2730,8 +2736,8 @@ compact(SourceHead) ->
 	       {ok, H} ->
 		   H;
 	       Error ->
-		   file:close(Fd),
-                   file:delete(Tmp),
+		   _ = file:close(Fd),
+                   _ = file:delete(Tmp),
 		   throw(Error)
 	   end,
 
@@ -2748,12 +2754,12 @@ compact(SourceHead) ->
 	    if 
 		R =:= ok -> ok;
 		true ->
-		    file:delete(Tmp),
+		    _ = file:delete(Tmp),
 		    throw(R)
 	    end;
 	Err ->
-	    file:close(Fd),
-            file:delete(Tmp),
+	    _ = file:close(Fd),
+            _ = file:delete(Tmp),
 	    throw(Err)
     end.
 	    
@@ -2777,7 +2783,7 @@ fsck(Fd, Tab, Fname, FH, MinSlotsArg, MaxSlotsArg, Version) ->
 	    BetterSlotNumbers = {MinSlots, BetterNoSlots, MaxSlots},
             case fsck_try(Fd, Tab, FH, Fname, BetterSlotNumbers, Version) of
                 {try_again, _} ->
-                    file:close(Fd),
+                    _ = file:close(Fd),
                     {error, {cannot_repair, Fname}};
                 Else ->
                     Else
@@ -2818,15 +2824,15 @@ fsck_try(Fd, Tab, FH, Fname, SlotNumbers, Version) ->
                     if 
 			R =:= ok -> ok;
 			true ->
-			    file:delete(Tmp),
+			    _ = file:delete(Tmp),
 			    R
 		    end;
 		TryAgainOrError ->
-                    file:delete(Tmp),
+                    _ = file:delete(Tmp),
                     TryAgainOrError
             end;
 	Error -> 
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    Error
     end.
 
@@ -2855,13 +2861,13 @@ fsck_try_est(Head, Fd, Fname, SlotNumbers, FH) ->
     Bulk = false,
     case Reply of 
         {ok, NoDups, H1} ->
-            file:close(Fd),
+            _ = file:close(Fd),
             fsck_copy(SizeData, H1, Bulk, NoDups);
         {try_again, _} = Return ->
             close_files(Bulk, SizeData, Head),
             Return;
         Else ->
-            file:close(Fd),
+            _ = file:close(Fd),
             close_files(Bulk, SizeData, Head),
 	    Else
     end.
@@ -2896,14 +2902,20 @@ fsck_copy1([SzData | L], Head, Bulk, NoDups) ->
     {LogSz, Pos, {FileName, Fd}, NoObjects} = SzData,
     Size = if NoObjects =:= 0 -> 0; true -> ?POW(LogSz-1) end,
     ExpectedSize = Size * NoObjects,
-    close_tmp(Fd),
-    case file:position(Out, Pos) of
-	{ok, Pos} -> ok;
-	PError -> dets_utils:file_error(FileName, PError)
+    case close_tmp(Fd) of
+        ok -> ok;
+        Err ->
+	    close_files(Bulk, L, Head),
+	    dets_utils:file_error(FileName, Err)
     end,
-    {ok, Pos} = file:position(Out, Pos),
+    case file:position(Out, Pos) of
+        {ok, Pos} -> ok;
+        Err2 ->
+	    close_files(Bulk, L, Head),
+	    dets_utils:file_error(Head#head.filename, Err2)
+        end,
     CR = file:copy({FileName, [raw,binary]}, Out),
-    file:delete(FileName),
+    _ = file:delete(FileName),
     case CR of 
 	{ok, Copied} when Copied =:= ExpectedSize;
 			  NoObjects =:= 0 -> % the segments
@@ -2937,11 +2949,11 @@ free_n_objects(Head, Addr, Size, N) ->
     free_n_objects(NewHead, NewAddr, Size, N-1).
 
 close_files(false, SizeData, Head) ->
-    file:close(Head#head.fptr),
+    _ = file:close(Head#head.fptr),
     close_files(true, SizeData, Head);
 close_files(true, SizeData, _Head) ->
     Fun = fun({_Size, _Pos, {FileName, Fd}, _No}) ->
-		  close_tmp(Fd),
+		  _ = close_tmp(Fd),
 		  file:delete(FileName);
 	     (_) ->
 		  ok
@@ -3261,7 +3273,7 @@ err(Error) ->
 file_info(FileName) ->
     case catch read_file_header(FileName, read, false) of
 	{ok, Fd, FH} ->
-	    file:close(Fd),
+	    _ = file:close(Fd),
             (FH#fileheader.mod):file_info(FH);
 	Other ->
 	    Other
@@ -3290,7 +3302,7 @@ view(FileName) ->
                         X ->
                             X
                     end
-            after file:close(Fd)
+            after _ = file:close(Fd)
             end;
 	X -> 
 	    X
diff --git a/lib/stdlib/src/dets_server.erl b/lib/stdlib/src/dets_server.erl
index 931112088e..268c201047 100644
--- a/lib/stdlib/src/dets_server.erl
+++ b/lib/stdlib/src/dets_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 2001-2009. All Rights Reserved.
+%% Copyright Ericsson AB 2001-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -241,8 +241,8 @@ ensure_started() ->
 init() ->
     set_verbose(verbose_flag()),
     process_flag(trap_exit, true),
-    ets:new(?REGISTRY, [set, named_table]),
-    ets:new(?OWNERS, [set, named_table]),
+    ?REGISTRY = ets:new(?REGISTRY, [set, named_table]),
+    ?OWNERS = ets:new(?OWNERS, [set, named_table]),
     ets:new(?STORE, [duplicate_bag]).
 
 verbose_flag() ->
@@ -338,7 +338,7 @@ handle_close(State, Req, {FromPid,_Tag}=From, Tab) ->
                         [{Tab, _Counter, Pid}] ->
 			    do_unlink(Store, FromPid),
 			    true = ets:match_delete(Store, {FromPid, Tab}),
-			    [true = ets:insert(Store, K) || K <- Keep],
+                            true = ets:insert(Store, Keep),
 			    ets:update_counter(?REGISTRY, Tab, -1),
                             pending_call(Tab, Pid, make_ref(), From, [],
                                          remove_user, State)
diff --git a/lib/stdlib/src/dets_utils.erl b/lib/stdlib/src/dets_utils.erl
index 7bbb34dd15..6c176ad513 100644
--- a/lib/stdlib/src/dets_utils.erl
+++ b/lib/stdlib/src/dets_utils.erl
@@ -230,8 +230,12 @@ write_file(Head, Bin) ->
 	    {ok, Fd} ->
 		R1 = file:write(Fd, Bin),
 		R2 = file:sync(Fd),
-		file:close(Fd),
-		if R1 =:= ok -> R2; true -> R1 end;
+		R3 = file:close(Fd),
+                case {R1, R2, R3} of
+                    {ok, ok, R3} -> R3;
+                    {ok, R2, _} -> R2;
+                    {R1, _, _} -> R1
+                end;
 	    Else ->
 		Else
 	end,
@@ -277,12 +281,7 @@ open(FileSpec, Args) ->
     end.
 
 truncate(Fd, FileName, Pos) ->
-    if
-	Pos =:= cur ->
-	    ok;
-	true ->
-	    position(Fd, FileName, Pos)
-    end,
+    _ = [position(Fd, FileName, Pos) || Pos =/= cur],
     case file:truncate(Fd) of
 	ok    -> 
 	    ok;
@@ -327,10 +326,10 @@ pread_close(Fd, FileName, Pos, Size) ->
 	{error, Error} ->
 	    file_error_close(Fd, FileName, {error, Error});
 	{ok, Bin} when byte_size(Bin) < Size ->
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    throw({error, {tooshort, FileName}});
 	eof ->
-	    file:close(Fd),
+	    _ = file:close(Fd),
 	    throw({error, {tooshort, FileName}});
 	OK -> OK
     end.
@@ -339,7 +338,7 @@ file_error(FileName, {error, Reason}) ->
     throw({error, {file_error, FileName, Reason}}).
 
 file_error_close(Fd, FileName, {error, Reason}) ->
-    file:close(Fd),
+    _ = file:close(Fd),
     throw({error, {file_error, FileName, Reason}}).
 	    
 debug_mode() ->
@@ -977,7 +976,8 @@ dm([{P,<<Sz:32,X:32>>} | Bs], T) ->
     true = ets:insert(T, {P,{pointer,X,Sz}}),
     if 
         Sz =:= 0 -> 
-            X = 0; 
+            X = 0,
+            true;
         true -> 
             true = ets:insert(T, {{pointer,X}, P})
     end,
diff --git a/lib/stdlib/src/dets_v8.erl b/lib/stdlib/src/dets_v8.erl
index 24d6e06ec8..f188502017 100644
--- a/lib/stdlib/src/dets_v8.erl
+++ b/lib/stdlib/src/dets_v8.erl
@@ -199,10 +199,10 @@
 %% -> ok | throw({NewHead,Error})
 mark_dirty(Head) ->
     Dirty = [{?CLOSED_PROPERLY_POS, <<?NOT_PROPERLY_CLOSED:32>>}],
-    dets_utils:pwrite(Head, Dirty),
-    dets_utils:sync(Head),
-    dets_utils:position(Head, Head#head.freelists_p),
-    dets_utils:truncate(Head, cur).
+    {_NewHead, ok} = dets_utils:pwrite(Head, Dirty),
+    ok = dets_utils:sync(Head),
+    {ok, _Pos} = dets_utils:position(Head, Head#head.freelists_p),
+    ok = dets_utils:truncate(Head, cur).
 
 %% -> {ok, head()} | throw(Error)
 initiate_file(Fd, Tab, Fname, Type, Kp, MinSlots, MaxSlots, 
diff --git a/lib/stdlib/src/dets_v9.erl b/lib/stdlib/src/dets_v9.erl
index 308f81c23b..2af93ec800 100644
--- a/lib/stdlib/src/dets_v9.erl
+++ b/lib/stdlib/src/dets_v9.erl
@@ -284,9 +284,9 @@
 %% -> ok | throw({NewHead,Error})
 mark_dirty(Head) ->
     Dirty = [{?CLOSED_PROPERLY_POS, <<?NOT_PROPERLY_CLOSED:32>>}],
-    dets_utils:pwrite(Head, Dirty),
-    dets_utils:sync(Head),
-    dets_utils:position(Head, Head#head.freelists_p),
+    {_H, ok} = dets_utils:pwrite(Head, Dirty),
+    ok = dets_utils:sync(Head),
+    {ok, _Pos} = dets_utils:position(Head, Head#head.freelists_p),
     dets_utils:truncate(Head, cur).
 
 %% -> {ok, head()} | throw(Error) | throw(badarg)
@@ -1385,13 +1385,13 @@ segment_file(SizeT, Head, FileData, SegEnd) ->
 	case Data of
 	    {InFile,In0} ->
 		{OutFile, Out} = temp_file(Head, SizeT, I),
-		file:close(In0),
+		_ = file:close(In0),
 		{ok, In} = dets_utils:open(InFile, [raw,binary,read]),
 		{ok, 0} = dets_utils:position(In, InFile, bof),
 		seg_file(SegAddr, SegAddr, In, InFile, Out, OutFile, SizeT, 
 			 SegEnd),
-		file:close(In),
-		file:delete(InFile),
+		_ = file:close(In),
+		_ = file:delete(InFile),
 		{OutFile,Out};
 	    Objects ->
 		{LastAddr, B} = seg_file(Objects, SegAddr, SegAddr, SizeT, []),
@@ -1702,7 +1702,7 @@ free_list_to_file(Ftab, H, Pos, Sz, Ws, WsSz) ->
     free_list_to_file(Ftab, H, Pos+1, Sz, NWs, NWsSz).
 
 free_lists_from_file(H, Pos) ->
-    dets_utils:position(H#head.fptr, H#head.filename, Pos),
+    {ok, Pos} = dets_utils:position(H#head.fptr, H#head.filename, Pos),
     FL = dets_utils:empty_free_lists(),
     case catch bin_to_tree([], H, start, FL, -1, []) of
 	{'EXIT', _} ->
diff --git a/lib/stdlib/src/digraph_utils.erl b/lib/stdlib/src/digraph_utils.erl
index 807b5c12a1..0e248df453 100644
--- a/lib/stdlib/src/digraph_utils.erl
+++ b/lib/stdlib/src/digraph_utils.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1999-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1999-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -370,5 +370,5 @@ condense('$end_of_table', _T, _SC, _G, _SCG, _I2C) ->
 condense(I, T, SC, G, SCG, I2C) ->
     [{_,C}] = ets:lookup(I2C, I),
     digraph:add_vertex(SCG, C),
-    [digraph:add_edge(SCG, SC, C) || C =/= SC],
+    _ = [digraph:add_edge(SCG, SC, C) || C =/= SC],
     condense(ets:next(T, I), T, SC, G, SCG, I2C).
diff --git a/lib/stdlib/src/epp.erl b/lib/stdlib/src/epp.erl
index 5bd6a224a2..dd0512be4d 100644
--- a/lib/stdlib/src/epp.erl
+++ b/lib/stdlib/src/epp.erl
@@ -644,7 +644,7 @@ leave_file(From, St) ->
 		    enter_file_reply(From, OldName, CurrLoc, CurrLoc),
                     case OldName2 =:= OldName of
                         true ->
-                            From;
+                            ok;
                         false ->
                             NFrom = wait_request(NextSt),
                             enter_file_reply(NFrom, OldName2, OldLoc,
diff --git a/lib/stdlib/src/erl_tar.erl b/lib/stdlib/src/erl_tar.erl
index 4b654833ed..f49c2a64f4 100644
--- a/lib/stdlib/src/erl_tar.erl
+++ b/lib/stdlib/src/erl_tar.erl
@@ -45,10 +45,7 @@ open(Name, Mode) ->
 open1({binary,Bin}, read, _Raw, Opts) ->
     case file:open(Bin, [ram,binary,read]) of
 	{ok,File} ->
-	    case Opts of
-		[compressed] -> ram_file:uncompress(File);
-		[] -> ok
-	    end,
+            _ = [ram_file:uncompress(File) || Opts =:= [compressed]],
 	    {ok,{read,File}};
 	Error ->
 	    Error
diff --git a/lib/stdlib/src/error_logger_tty_h.erl b/lib/stdlib/src/error_logger_tty_h.erl
index ad5891f191..e92142d154 100644
--- a/lib/stdlib/src/error_logger_tty_h.erl
+++ b/lib/stdlib/src/error_logger_tty_h.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -54,7 +54,7 @@ init([]) ->
 handle_event({_Type, GL, _Msg}, State) when node(GL) =/= node() ->
     {ok, State};
 handle_event(Event, State) ->
-    write_event(tag_event(Event),io),
+    ok = write_event(tag_event(Event),io),
     {ok, State}.
 
 handle_info({'EXIT', User, _Reason}, {User, PrevHandler}) ->
@@ -66,10 +66,10 @@ handle_info({'EXIT', User, _Reason}, {User, PrevHandler}) ->
 	     PrevHandler, go_back}
     end;
 handle_info({emulator, GL, Chars}, State) when node(GL) == node() ->
-    write_event(tag_event({emulator, GL, Chars}),io),
+    ok = write_event(tag_event({emulator, GL, Chars}),io),
     {ok, State};
 handle_info({emulator, noproc, Chars}, State) ->
-    write_event(tag_event({emulator, noproc, Chars}),io),
+    ok = write_event(tag_event({emulator, noproc, Chars}),io),
     {ok, State};
 handle_info(_, State) ->
     {ok, State}.
@@ -99,10 +99,11 @@ set_group_leader() ->
 tag_event(Event) ->    
     {erlang:universaltime(), Event}.
 
+%% IOMOd is always 'io'
 write_events(Events,IOMod) -> write_events1(lists:reverse(Events),IOMod).
 
 write_events1([Event|Es],IOMod) ->
-    write_event(Event,IOMod),
+    ok = write_event(Event,IOMod),
     write_events1(Es,IOMod);
 write_events1([],_IOMod) ->
     ok.
diff --git a/lib/stdlib/src/escript.erl b/lib/stdlib/src/escript.erl
index fea718541d..35f6dff57e 100644
--- a/lib/stdlib/src/escript.erl
+++ b/lib/stdlib/src/escript.erl
@@ -771,9 +771,11 @@ interpret(Forms, HasRecs,  File, Args) ->
     ArgsA = erl_parse:abstract(Args, 0),
     Call = {call,0,{atom,0,main},[ArgsA]},
     try
-        erl_eval:expr(Call,
-                      erl_eval:new_bindings(),
-                      {value,fun(I, J) -> code_handler(I, J, Dict, File) end}),
+        _ = erl_eval:expr(Call,
+                          erl_eval:new_bindings(),
+                          {value,fun(I, J) ->
+                                         code_handler(I, J, Dict, File)
+                                 end}),
         my_halt(0)
     catch
         Class:Reason ->
diff --git a/lib/stdlib/src/ets.erl b/lib/stdlib/src/ets.erl
index 77c8029f59..87e6502668 100644
--- a/lib/stdlib/src/ets.erl
+++ b/lib/stdlib/src/ets.erl
@@ -719,7 +719,7 @@ tab2file(Tab, File) ->
 tab2file(Tab, File, Options) ->
     try
 	{ok, FtOptions} = parse_ft_options(Options),
-	file:delete(File),
+	_ = file:delete(File),
 	case file:read_file_info(File) of
 	    {error, enoent} -> ok;
 	    _ -> throw(eaccess)
@@ -750,14 +750,18 @@ tab2file(Tab, File, Options) ->
 		    {fun(Oldstate,Termlist) ->
 			     {NewState,BinList} = 
 				 md5terms(Oldstate,Termlist),
-			     disk_log:blog_terms(Name,BinList),
-			     NewState
+                             case disk_log:blog_terms(Name,BinList) of
+                                 ok -> NewState;
+                                 {error, Reason2} -> throw(Reason2)
+                             end
 		     end,
 		     erlang:md5_init()};
 		false ->
 		    {fun(_,Termlist) ->
-			     disk_log:log_terms(Name,Termlist),
-			     true
+                             case disk_log:log_terms(Name,Termlist) of
+                                 ok -> true;
+                                 {error, Reason2} -> throw(Reason2)
+                             end
 		     end, 
 		     true}
 	    end,
@@ -792,16 +796,16 @@ tab2file(Tab, File, Options) ->
 	    disk_log:close(Name)
 	catch
 	    throw:TReason ->
-		disk_log:close(Name),
-		file:delete(File),
+		_ = disk_log:close(Name),
+		_ = file:delete(File),
 		throw(TReason);
 	    exit:ExReason ->
-		disk_log:close(Name),
-		file:delete(File),
+		_ = disk_log:close(Name),
+		_ = file:delete(File),
 		exit(ExReason);
 	    error:ErReason ->
-		disk_log:close(Name),
-		file:delete(File),
+		_ = disk_log:close(Name),
+		_ = file:delete(File),
 	        erlang:raise(error,ErReason,erlang:get_stacktrace())
 	end
     catch
@@ -901,7 +905,7 @@ file2tab(File, Opts) ->
 		{repaired, Name, _,_} -> %Uh? cannot happen?
 		    case Verify of
 			true ->
-			    disk_log:close(Name),
+			    _ = disk_log:close(Name),
 			    throw(badfile);
 			false ->
 			    get_header_data(Name,Verify)
@@ -1306,7 +1310,10 @@ tabfile_info(File) when is_list(File) ; is_atom(File) ->
 		Other2 ->
 		    throw(Other2)
 	    end,
-	disk_log:close(Name),
+        case disk_log:close(Name) of
+            ok -> ok;
+            {error, Reason} -> throw(Reason)
+        end,
 	{value, N} = lists:keysearch(name, 1, FullHeader),
 	{value, Type} = lists:keysearch(type, 1, FullHeader),
 	{value, P} = lists:keysearch(protection, 1, FullHeader),
diff --git a/lib/stdlib/src/file_sorter.erl b/lib/stdlib/src/file_sorter.erl
index 2bf88959b7..687d72b4bd 100644
--- a/lib/stdlib/src/file_sorter.erl
+++ b/lib/stdlib/src/file_sorter.erl
@@ -547,7 +547,7 @@ files(_I, L, _LSz, #w{seq = 1, out = Out}=W, []) ->
             NW = close_input(W1),
             outfun(close, NW);
         Out ->
-            write_run(L, W, Out),
+            _ = write_run(L, W, Out),
             ok
     end;
 files(_I, L, _LSz, W, []) ->
@@ -638,7 +638,7 @@ last_merge(R, W) when length(R) =< W#w.no_files ->
             NW = close_input(W2),
             outfun(close, NW);
         Out ->
-            merge_files(R, W, Out),
+            _ = merge_files(R, W, Out),
             ok
     end;
 last_merge(R, W) ->
@@ -1110,10 +1110,12 @@ read_fun2(Fd, Bin, Size, FileName, Owner) ->
     end.
        
 close_read_fun(Fd, _FileName, user) ->
-    file:close(Fd);
+    _ = file:close(Fd),
+    ok;
 close_read_fun(Fd, FileName, fsort) ->
-    file:close(Fd),
-    file:delete(FileName).
+    _ = file:close(Fd),
+    _ = file:delete(FileName),
+    ok.
 
 read_objs(Fd, FileName, I, L, Bin0, Size0, LSz, W) ->
     Max = erlang:max(Size0, ?CHUNKSIZE),
@@ -1481,10 +1483,10 @@ cleanup(W) ->
     F = fun(IFun) when is_function(IFun) -> 
                 IFun(close);
            ({Fd,FileName}) ->
-                file:close(Fd),
-                file:delete(FileName);
+                _ = file:close(Fd),
+                _= file:delete(FileName);
            (FileName) -> 
-                file:delete(FileName)
+                _= file:delete(FileName)
         end,
     lists:foreach(F, W1#w.temp).
 
@@ -1502,8 +1504,12 @@ close_out(_) ->
 close_file(Fd, W) ->
     {Fd, FileName} = lists:keyfind(Fd, 1, W#w.temp),
     ?DEBUG("closing ~tp~n", [FileName]),
-    file:close(Fd),
-    W#w{temp = [FileName | lists:keydelete(Fd, 1, W#w.temp)]}.
+    case file:close(Fd) of
+        ok ->
+            W#w{temp = [FileName | lists:keydelete(Fd, 1, W#w.temp)]};
+        Error ->
+            file_error(FileName, Error, W)
+    end.
 
 %%%
 %%% Format 'term'.
@@ -1536,10 +1542,10 @@ file_rterms2(Fd, L, LSz, FileName, Files) when LSz < ?CHUNKSIZE ->
             B = term_to_binary(Term),
             file_rterms2(Fd, [B | L], LSz + byte_size(B), FileName, Files);
         eof ->
-            file:close(Fd),
+            _ = file:close(Fd),
             {lists:reverse(L), file_rterms(no_file, Files)};
         _Error ->
-            file:close(Fd),
+            _ = file:close(Fd),
             {error, {bad_term, FileName}}
     end;
 file_rterms2(Fd, L, _LSz, FileName, Files) ->
@@ -1568,7 +1574,7 @@ write_terms(Fd, F, [B | Bs], Args) ->
         ok -> 
             write_terms(Fd, F, Bs, Args);
         {error, Reason} ->
-            file:close(Fd),
+            _ = file:close(Fd),
             {error, {file_error, F, Reason}}
     end;
 write_terms(Fd, F, [], Args) ->
diff --git a/lib/stdlib/src/filelib.erl b/lib/stdlib/src/filelib.erl
index 42ef3679a2..42885bcdcf 100644
--- a/lib/stdlib/src/filelib.erl
+++ b/lib/stdlib/src/filelib.erl
@@ -231,7 +231,7 @@ ensure_dir(F) ->
 	    %% Protect against infinite loop
 	    {error,einval};
 	false ->
-	    ensure_dir(Dir),
+	    _ = ensure_dir(Dir),
 	    case file:make_dir(Dir) of
 		{error,eexist}=EExist ->
 		    case do_is_dir(Dir, file) of
diff --git a/lib/stdlib/src/gen_fsm.erl b/lib/stdlib/src/gen_fsm.erl
index d9411e58cf..e9654322f1 100644
--- a/lib/stdlib/src/gen_fsm.erl
+++ b/lib/stdlib/src/gen_fsm.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -549,7 +549,7 @@ handle_msg(Msg, Parent, Name, StateName, StateData, Mod, _Time, Debug) ->
 	{stop, Reason, Reply, NStateData} when From =/= undefined ->
 	    {'EXIT', R} = (catch terminate(Reason, Name, Msg, Mod,
 					   StateName, NStateData, Debug)),
-	    reply(Name, From, Reply, Debug, StateName),
+	    _ = reply(Name, From, Reply, Debug, StateName),
 	    exit(R);
 	{'EXIT', What} ->
 	    terminate(What, Name, Msg, Mod, StateName, StateData, Debug);
diff --git a/lib/stdlib/src/gen_server.erl b/lib/stdlib/src/gen_server.erl
index 30a81ade49..4a16ed120f 100644
--- a/lib/stdlib/src/gen_server.erl
+++ b/lib/stdlib/src/gen_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -623,7 +623,7 @@ handle_msg({'$gen_call', From, Msg}, Parent, Name, State, Mod, Debug) ->
 	{stop, Reason, Reply, NState} ->
 	    {'EXIT', R} = 
 		(catch terminate(Reason, Name, Msg, Mod, NState, Debug)),
-	    reply(Name, From, Reply, NState, Debug),
+	    _ = reply(Name, From, Reply, NState, Debug),
 	    exit(R);
 	Other ->
 	    handle_common_reply(Other, Parent, Name, Msg, Mod, State, Debug)
diff --git a/lib/stdlib/src/log_mf_h.erl b/lib/stdlib/src/log_mf_h.erl
index 19b555a48c..6b42363979 100644
--- a/lib/stdlib/src/log_mf_h.erl
+++ b/lib/stdlib/src/log_mf_h.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -135,7 +135,12 @@ handle_event(Event, State) ->
 			State#state{cur_fd = NewFd, curF = NewF, curB = 0}
 		end,
 	    [Hi,Lo] = put_int16(Size),
-	    file:write(NewState#state.cur_fd, [Hi, Lo, Bin]),
+            case file:write(NewState#state.cur_fd, [Hi, Lo, Bin]) of
+                ok ->
+                    ok;
+                {error, Reason} ->
+                    exit({file_exit, Reason})
+            end,
 	    {ok, NewState#state{curB = NewState#state.curB + Size + 2}};
 	_ ->
 	    {ok, State}
@@ -174,7 +179,7 @@ file_open(Dir, FileNo) ->
 	    write_index_file(Dir, FileNo),
 	    {ok, Fd};
 	_ -> 
-	    exit({file, open})
+	    exit(file_open)
     end.
 
 put_int16(I) ->
@@ -211,7 +216,7 @@ write_index_file(Dir, Index) ->
 	    ok = file:close(Fd),
 	    ok = file:rename(TmpFile,File),
 	    ok;
-	_ -> exit(open_index_file)
+	_ -> exit(write_index_file)
     end.
 
 inc(N, Max) ->
diff --git a/lib/stdlib/src/pool.erl b/lib/stdlib/src/pool.erl
index a5eb191ab2..dfe6318dea 100644
--- a/lib/stdlib/src/pool.erl
+++ b/lib/stdlib/src/pool.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -63,7 +63,7 @@ start(Name) ->
       Args :: string(),
       Nodes :: [node()].
 start(Name, Args) when is_atom(Name) ->
-    gen_server:start({global, pool_master}, pool, [], []),
+    _ = gen_server:start({global, pool_master}, pool, [], []),
     Hosts = net_adm:host_file(),
     Nodes = start_nodes(Hosts, Name, Args),
     lists:foreach(fun attach/1, Nodes),
diff --git a/lib/stdlib/src/shell.erl b/lib/stdlib/src/shell.erl
index c6c706c3a7..0d2fc47d13 100644
--- a/lib/stdlib/src/shell.erl
+++ b/lib/stdlib/src/shell.erl
@@ -58,7 +58,7 @@ start(NoCtrlG) ->
     start(NoCtrlG, false).
 
 start(NoCtrlG, StartSync) ->
-    code:ensure_loaded(user_default),
+    _ = code:ensure_loaded(user_default),
     spawn(fun() -> server(NoCtrlG, StartSync) end).
 
 %% Find the pid of the current evaluator process.
@@ -677,8 +677,10 @@ exprs([E0|Es], Bs1, RT, Lf, Ef, Bs0, W) ->
             if
                 Es =:= [] ->
                     VS = pp(V0, 1, RT),
-                    [io:requests([{put_chars, unicode, VS}, nl]) ||
-                        W =:= cmd],
+                    case W of
+                        cmd -> io:requests([{put_chars, unicode, VS}, nl]);
+                        pmt -> ok
+                    end,
                     %% Don't send the result back if it will be
                     %% discarded anyway.
                     V = if
diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl
index 54328cd9ff..26821e0e09 100644
--- a/lib/stdlib/src/supervisor.erl
+++ b/lib/stdlib/src/supervisor.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -260,7 +260,7 @@ init_children(State, StartSpec) ->
                 {ok, NChildren} ->
                     {ok, State#state{children = NChildren}};
                 {error, NChildren, Reason} ->
-                    terminate_children(NChildren, SupName),
+                    _ = terminate_children(NChildren, SupName),
                     {stop, {shutdown, Reason}}
             end;
         Error ->
@@ -752,7 +752,10 @@ restart(Child, State) ->
 		    Id = if ?is_simple(State) -> Child#child.pid;
 			    true -> Child#child.name
 			 end,
-		    timer:apply_after(0,?MODULE,try_again_restart,[self(),Id]),
+		    {ok, _TRef} = timer:apply_after(0,
+                                                    ?MODULE,
+                                                    try_again_restart,
+                                                    [self(),Id]),
 		    {ok,NState2};
 		{try_again, NState2, #child{name=ChName}} ->
 		    timer:apply_after(0,?MODULE,try_again_restart,[self(),ChName]),
@@ -850,7 +853,7 @@ terminate_children(Children, SupName) ->
 %% we do want them to be shut down as many functions from this module
 %% use this function to just clear everything.
 terminate_children([Child = #child{restart_type=temporary} | Children], SupName, Res) ->
-    do_terminate(Child, SupName),
+    _ = do_terminate(Child, SupName),
     terminate_children(Children, SupName, Res);
 terminate_children([Child | Children], SupName, Res) ->
     NChild = do_terminate(Child, SupName),
@@ -1008,7 +1011,7 @@ wait_dynamic_children(_Child, _Pids, 0, undefined, EStack) ->
 wait_dynamic_children(_Child, _Pids, 0, TRef, EStack) ->
 	%% If the timer has expired before its cancellation, we must empty the
 	%% mail-box of the 'timeout'-message.
-    erlang:cancel_timer(TRef),
+    _ = erlang:cancel_timer(TRef),
     receive
         {timeout, TRef, kill} ->
             EStack
diff --git a/lib/stdlib/src/sys.erl b/lib/stdlib/src/sys.erl
index bffeb44179..5359a6d5bc 100644
--- a/lib/stdlib/src/sys.erl
+++ b/lib/stdlib/src/sys.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %% 
-%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %% 
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -320,7 +320,7 @@ handle_system_msg(SysState, Msg, From, Parent, Mod, Debug, Misc, Hib) ->
 	    gen:reply(From, Reply),
 	    suspend_loop(suspended, Parent, Mod, NDebug, NMisc, Hib);
 	{running, Reply, NDebug, NMisc} ->
-	    gen:reply(From, Reply),
+	    _ = gen:reply(From, Reply),
             Mod:system_continue(Parent, NDebug, NMisc)
     end.
 
diff --git a/lib/stdlib/src/timer.erl b/lib/stdlib/src/timer.erl
index e11fb046e9..72a2dd9616 100644
--- a/lib/stdlib/src/timer.erl
+++ b/lib/stdlib/src/timer.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 1996-2011. All Rights Reserved.
+%% Copyright Ericsson AB 1996-2013. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -258,7 +258,7 @@ ensure_started() ->
 	undefined -> 
 	    C = {timer_server, {?MODULE, start_link, []}, permanent, 1000, 
 		 worker, [?MODULE]},
-	    supervisor:start_child(kernel_safe_sup, C),  % kernel_safe_sup
+	    _ = supervisor:start_child(kernel_safe_sup, C),
 	    ok;
 	_ -> ok
     end.