Fix file:pread and :pwrite to use character encoding

2 files changed, 75 insertions, 8 deletions

diff --git a/lib/kernel/src/file_io_server.erl b/lib/kernel/src/file_io_server.erl
index 5b2cae6b02..9c425d2175 100644
--- a/lib/kernel/src/file_io_server.erl
+++ b/lib/kernel/src/file_io_server.erl
@@ -214,26 +214,58 @@ file_request({allocate, Offset, Length},
          #state{handle = Handle} = State) ->
     Reply = ?PRIM_FILE:allocate(Handle, Offset, Length),
     {reply, Reply, State};
+file_request({pread,At,Sz}, State)
+  when At =:= cur;
+       At =:= {cur,0} ->
+    case get_chars(Sz, latin1, State) of
+	{reply,Reply,NewState}
+	  when is_list(Reply);
+	       is_binary(Reply) ->
+	    {reply,{ok,Reply},NewState};
+	{stop,_,Reply,NewState} ->
+	    {error,Reply,NewState};
+	Other ->
+	    Other
+    end;
 file_request({pread,At,Sz}, 
-	     #state{handle=Handle,buf=Buf,read_mode=ReadMode}=State) ->
+	     #state{handle=Handle,buf=Buf}=State) ->
     case position(Handle, At, Buf) of
 	{error,_} = Reply ->
 	    {error,Reply,State};
 	_ ->
-	    case ?PRIM_FILE:read(Handle, Sz) of
-		{ok,Bin} when ReadMode =:= list ->
-		    std_reply({ok,binary_to_list(Bin)}, State);
-		Reply ->
-		    std_reply(Reply, State)
+	    case get_chars(Sz, latin1, State#state{buf= <<>>}) of
+		{reply,Reply,NewState}
+		  when is_list(Reply);
+		       is_binary(Reply) ->
+		    {reply,{ok,Reply},NewState};
+		{stop,_,Reply,NewState} ->
+		    {error,Reply,NewState};
+		Other ->
+		    Other
 	    end
     end;
+file_request({pwrite,At,Data},
+	     #state{buf= <<>>}=State)
+  when At =:= cur;
+       At =:= {cur,0} ->
+    case put_chars(Data, latin1, State) of
+	{stop,_,Reply,NewState} ->
+	    {error,Reply,NewState};
+	Other ->
+	    Other
+    end;
 file_request({pwrite,At,Data}, 
 	     #state{handle=Handle,buf=Buf}=State) ->
     case position(Handle, At, Buf) of
 	{error,_} = Reply ->
 	    {error,Reply,State};
 	_ ->
-	    std_reply(?PRIM_FILE:write(Handle, Data), State)
+	    case put_chars(Data, latin1, State) of
+		{stop,_,Reply,NewState} ->
+		    {error,Reply,NewState};
+		Other ->
+		    Other
+	    end
     end;
 file_request(datasync,
 	     #state{handle=Handle}=State) ->
diff --git a/lib/kernel/test/file_SUITE.erl b/lib/kernel/test/file_SUITE.erl
index e9300bf019..87d2de4cae 100644
--- a/lib/kernel/test/file_SUITE.erl
+++ b/lib/kernel/test/file_SUITE.erl
@@ -79,6 +79,7 @@
 
 -export([interleaved_read_write/1]).
 
+-export([unicode/1]).
 -export([altname/1]).
 
 -export([large_file/1, large_write/1]).
@@ -110,7 +111,7 @@
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
-    [altname, read_write_file, {group, dirs},
+    [unicode, altname, read_write_file, {group, dirs},
      {group, files}, delete, rename, names, {group, errors},
      {group, compression}, {group, links}, copy,
      delayed_write, read_ahead, segment_read, segment_write,
@@ -2631,6 +2632,40 @@ compress_async_crash_loop(N, Path, ExpectedData) ->
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+unicode(Config) when is_list(Config) ->
+    Dir = ?config(priv_dir, Config),
+    Name = filename:join(Dir, "data-utf8.txt"),
+    Txt = lists:seq(128, 255),
+    D = unicode:characters_to_binary(Txt, latin1, latin1),
+    {ok,Fd1} =
+	?FILE_MODULE:open(Name, [write,read,binary,{encoding,unicode}]),
+    ok = ?FILE_MODULE:truncate(Fd1),
+    ok = ?FILE_MODULE:write(Fd1, Txt),
+    {ok,0} = ?FILE_MODULE:position(Fd1, bof),
+    {ok,D} = ?FILE_MODULE:read(Fd1, 129),
+    {ok,0} = ?FILE_MODULE:position(Fd1, bof),
+    {ok,D1} = ?FILE_MODULE:read(Fd1, 64),
+    {ok,Pos} = ?FILE_MODULE:position(Fd1, cur),
+    {ok,D2} = ?FILE_MODULE:pread(Fd1, {cur,0}, 65),
+    D = <<D1/binary, D2/binary>>,
+    {ok,D1} = ?FILE_MODULE:pread(Fd1, bof, 64),
+    {ok,Pos} = ?FILE_MODULE:position(Fd1, Pos),
+    {ok,D2} = ?FILE_MODULE:read(Fd1, 64),
+    ok = ?FILE_MODULE:close(Fd1),
+    %%
+    RawD = unicode:characters_to_binary(Txt, latin1, unicode),
+    {ok,RawD} = ?FILE_MODULE:read_file(Name),
+    %%
+    {ok,Fd2} = ?FILE_MODULE:open(Name, [read,{encoding,unicode}]),
+    {ok,Txt} = ?FILE_MODULE:read(Fd2, 129),
+    {Txt1,Txt2} = lists:split(64, Txt),
+    {ok,Txt2} = ?FILE_MODULE:pread(Fd2, Pos, 65),
+    {ok,0} = ?FILE_MODULE:position(Fd2, bof),
+    {ok,Txt1} = ?FILE_MODULE:read(Fd2, 64),
+    ok = ?FILE_MODULE:close(Fd2).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
 altname(doc) ->
     "Test the file:altname/1 function";
 altname(suite) ->