Merge branch 'ta/ensure_dir_eexist' into ccase/r13b04_dev

* ta/ensure_dir_eexist:
  filelib_SUITE: strenghten tests of filelib:ensure_dir/1
  Don't return a false {error,eexist} in filelib:ensure_dir/1

OTP-8389  Because of a race condition, using filelib:ensure_dir/1 from
          multiple processes to create the same path or parts of the same
          directory structure, filelib:ensure_dir/1 could return a
          meaningless {error,eexist}. That race condition has been
          eliminated, and {error,eexist} will now be returned only if there
          exists a regular file, device file, or some other non-directory
          file with the same name. (Thanks to Tuncer Ayaz.)

1 files changed, 16 insertions, 6 deletions

diff --git a/lib/stdlib/src/filelib.erl b/lib/stdlib/src/filelib.erl
index d65588f0d1..74c5172137 100644
--- a/lib/stdlib/src/filelib.erl
+++ b/lib/stdlib/src/filelib.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1997-2010. 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
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 
 -module(filelib).
@@ -228,7 +228,17 @@ ensure_dir(F) ->
 	    ok;
 	false ->
 	    ensure_dir(Dir),
-	    file:make_dir(Dir)
+	    case file:make_dir(Dir) of
+		{error,eexist}=EExist ->
+		    case do_is_dir(Dir, file) of
+			true ->
+			    ok;
+			false ->
+			    EExist
+		    end;
+		Err ->
+		    Err
+	    end
     end.