Fix segfault in module_info for deleted modules

Add a check to protect from segfault when erlang:get_module_info/1/2 is
called on a deleted module (i.e. with no current code). Also refactor
erts_module_info_0/1 to avoid repeated calls to erts_active_code_ix() and
remove some obsolete comments. Add test for module_info on deleted modules.

1 files changed, 24 insertions, 0 deletions

diff --git a/erts/emulator/test/module_info_SUITE_data/module_info_test.erl b/erts/emulator/test/module_info_SUITE_data/module_info_test.erl
new file mode 100644
index 0000000000..f045f38464
--- /dev/null
+++ b/erts/emulator/test/module_info_SUITE_data/module_info_test.erl
@@ -0,0 +1,24 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2015. 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(module_info_test).
+-export([f/0]).
+
+f() ->
+    17.