Ensure cover keeps the proper file source

Whenever a module is compiled via compile:forms/2,
the source is set to current directory unless a source
option is passed to compile. This commit ensures that
cover passes the source information to compile:forms/2
to ensure the source won't be modified after the module
is cover compiled.

1 files changed, 17 insertions, 1 deletions

diff --git a/lib/tools/src/cover.erl b/lib/tools/src/cover.erl
index d7c736b710..3cf42662f8 100644
--- a/lib/tools/src/cover.erl
+++ b/lib/tools/src/cover.erl
@@ -1372,10 +1372,15 @@ do_compile_beam(Module,Beam,UserOptions) ->
             Forms0 = epp:interpret_file_attribute(Code),
 	    {Forms,Vars} = transform(Vsn, Forms0, Module, Beam),
 
+	    %% We need to recover the source from the compilation
+	    %% info otherwise the newly compiled module will have
+	    %% source pointing to the current directory
+	    SourceInfo = get_source_info(Module, Beam),
+
 	    %% Compile and load the result
 	    %% It's necessary to check the result of loading since it may
 	    %% fail, for example if Module resides in a sticky directory
-	    {ok, Module, Binary} = compile:forms(Forms, UserOptions),
+	    {ok, Module, Binary} = compile:forms(Forms, SourceInfo ++ UserOptions),
 	    case code:load_binary(Module, ?TAG, Binary) of
 		{module, Module} ->
 		    
@@ -1403,6 +1408,17 @@ get_abstract_code(Module, Beam) ->
 	Error -> Error
     end.
 
+get_source_info(Module, Beam) ->
+    case beam_lib:chunks(Beam, [compile_info]) of
+	{ok, {Module, [{compile_info, Compile}]}} ->
+		case lists:keyfind(source, 1, Compile) of
+			{ source, _ } = Tuple -> [Tuple];
+			false -> []
+		end;
+	_ ->
+		[]
+    end.
+
 transform(Vsn, Code, Module, Beam) when Vsn=:=abstract_v1; Vsn=:=abstract_v2 ->
     Vars0 = #vars{module=Module, vsn=Vsn},
     MainFile=find_main_filename(Code),