Merge pull request #1838 from crownedgrouse/master

 Included config files relative to sys.config directory

OTP-15137

3 files changed, 67 insertions, 13 deletions

diff --git a/lib/kernel/doc/src/config.xml b/lib/kernel/doc/src/config.xml
index 8850c1736b..3f01170508 100644
--- a/lib/kernel/doc/src/config.xml
+++ b/lib/kernel/doc/src/config.xml
@@ -86,8 +86,13 @@
       <tag><c>File = string()</c></tag>
       <item>Name of another <c>.config</c> file.
         Extension <c>.config</c> can be omitted. It is
-        recommended to use absolute paths. A relative path is
-        relative the current working directory of the emulator.</item>
+        recommended to use absolute paths. If a relative path is used,
+        <c>File</c> is searched, first, relative from <c>sys.config</c> directory, then relative
+        to the current working directory of the emulator, for backward compatibility.
+        This allow to use a <c>sys.config</c> pointing out other <c>.config</c> files in a release
+        or in a node started manually using <c>-config ...</c> with same result whatever
+        the current working directory.
+        </item>
     </taglist>
     <p>When traversing the contents of <c>sys.config</c> and a filename
       is encountered, its contents are read and merged with the result
diff --git a/lib/kernel/src/application_controller.erl b/lib/kernel/src/application_controller.erl
index 0dad6ae935..a074d2e74b 100644
--- a/lib/kernel/src/application_controller.erl
+++ b/lib/kernel/src/application_controller.erl
@@ -1814,8 +1814,9 @@ check_conf() ->
 				   %% Therefore read and merge contents.
 				   if
 				       BFName =:= "sys" ->
+					   DName = filename:dirname(FName),
 					   {ok, SysEnv, Errors} =
-					       check_conf_sys(NewEnv),
+					       check_conf_sys(NewEnv, [], [], DName),
 
 					   %% Report first error, if any, and
 					   %% terminate
@@ -1837,20 +1838,31 @@ check_conf() ->
     end.
 
 check_conf_sys(Env) ->
-    check_conf_sys(Env, [], []).
+    check_conf_sys(Env, [], [], []).
 
-check_conf_sys([File|T], SysEnv, Errors) when is_list(File) ->
+check_conf_sys([File|T], SysEnv, Errors, DName) when is_list(File),is_list(DName) ->
     BFName = filename:basename(File, ".config"),
     FName = filename:join(filename:dirname(File), BFName ++ ".config"),
-    case load_file(FName) of
+    LName = case filename:pathtype(FName) of
+               relative when (DName =/= []) ->
+                  % Check if relative to sys.config dir otherwise use legacy mode,
+                  % i.e relative to cwd.
+                  RName = filename:join(DName, FName),
+                  case erl_prim_loader:read_file_info(RName) of
+                     {ok, _} -> RName ;
+                     error   -> FName
+                  end;
+		_          -> FName
+	    end,
+    case load_file(LName) of
 	{ok, NewEnv} ->
-	    check_conf_sys(T, merge_env(SysEnv, NewEnv), Errors);
+	    check_conf_sys(T, merge_env(SysEnv, NewEnv), Errors, DName);
 	{error, {Line, _Mod, Str}} ->
-	    check_conf_sys(T, SysEnv, [{error, {FName, Line, Str}}|Errors])
+	    check_conf_sys(T, SysEnv, [{error, {LName, Line, Str}}|Errors], DName)
     end;
-check_conf_sys([Tuple|T], SysEnv, Errors) ->
-    check_conf_sys(T, merge_env(SysEnv, [Tuple]), Errors);
-check_conf_sys([], SysEnv, Errors) ->
+check_conf_sys([Tuple|T], SysEnv, Errors, DName) ->
+    check_conf_sys(T, merge_env(SysEnv, [Tuple]), Errors, DName);
+check_conf_sys([], SysEnv, Errors, _) ->
     {ok, SysEnv, lists:reverse(Errors)}.
 
 load_file(File) ->
diff --git a/lib/kernel/test/application_SUITE.erl b/lib/kernel/test/application_SUITE.erl
index 988f26280f..3d07d6d70d 100644
--- a/lib/kernel/test/application_SUITE.erl
+++ b/lib/kernel/test/application_SUITE.erl
@@ -37,7 +37,8 @@
 -export([config_change/1, persistent_env/1,
 	 distr_changed_tc1/1, distr_changed_tc2/1,
 	 ensure_started/1, ensure_all_started/1,
-	 shutdown_func/1, do_shutdown/1, shutdown_timeout/1, shutdown_deadlock/1]).
+	 shutdown_func/1, do_shutdown/1, shutdown_timeout/1, shutdown_deadlock/1,
+         config_relative_paths/1]).
 
 -define(TESTCASE, testcase_name).
 -define(testcase, proplists:get_value(?TESTCASE, Config)).
@@ -55,7 +56,7 @@ all() ->
      script_start, nodedown_start, permit_false_start_local,
      permit_false_start_dist, get_key, get_env, ensure_all_started,
      {group, distr_changed}, config_change, shutdown_func, shutdown_timeout,
-     shutdown_deadlock,
+     shutdown_deadlock, config_relative_paths,
      persistent_env].
 
 groups() -> 
@@ -2075,6 +2076,42 @@ shutdown_deadlock(Config) when is_list(Config) ->
 
 
 %%-----------------------------------------------------------------
+%% Relative paths in sys.config
+%%-----------------------------------------------------------------
+config_relative_paths(Config) ->
+    Dir = ?config(priv_dir,Config),
+    SubDir = filename:join(Dir,"subdir"),
+    Sys = filename:join(SubDir,"sys.config"),
+    ok = filelib:ensure_dir(Sys),
+    ok = file:write_file(Sys,"[\"../up.config\",\"current\"].\n"),
+
+    Up = filename:join(Dir,"up.config"),
+    ok = file:write_file(Up,"[{app1,[{key1,value}]}].\n"),
+
+    {ok,Cwd} = file:get_cwd(),
+    Current1 = filename:join(Cwd,"current.config"),
+    ok = file:write_file(Current1,"[{app1,[{key2,value1}]}].\n"),
+
+    N1 = list_to_atom(lists:concat([?FUNCTION_NAME,"_1"])),
+    {ok,Node1} = start_node(N1,filename:rootname(Sys)),
+    ok = rpc:call(Node1, application, load, [app1()]),
+    {ok, value} = rpc:call(Node1, application, get_env,[app1,key1]),
+    {ok, value1} = rpc:call(Node1, application, get_env,[app1,key2]),
+
+    Current2 = filename:join(SubDir,"current.config"),
+    ok = file:write_file(Current2,"[{app1,[{key2,value2}]}].\n"),
+
+    N2 = list_to_atom(lists:concat([?FUNCTION_NAME,"_2"])),
+    {ok, Node2} = start_node(N2,filename:rootname(Sys)),
+    ok = rpc:call(Node2, application, load, [app1()]),
+    {ok, value} = rpc:call(Node2, application, get_env,[app1,key1]),
+    {ok, value2} = rpc:call(Node2, application, get_env,[app1,key2]),
+
+    stop_node_nice([Node1,Node2]),
+
+    ok.
+
+%%-----------------------------------------------------------------
 %% Utility functions
 %%-----------------------------------------------------------------
 app0() ->