Merge branch 'bjorn/fun-improvements/OTP-9667'

* bjorn/fun-improvements/OTP-9667:
  sys_pre_expand: Remove incorrect comment
  compiler: Eliminate use of deprecated erlang:hash/2
  beam_asm: Fix broken NewIndex in fun entries
  beam_asm: Strenghten the calculation of Uniq for funs

3 files changed, 64 insertions, 4 deletions

diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 45b66a4909..5d7ff7613b 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -1196,11 +1196,16 @@ true
           </item>
           <tag><c>{new_uniq, Uniq}</c></tag>
           <item>
-            <p><c>Uniq</c> (a binary) is a unique value for this fun.</p>
+            <p><c>Uniq</c> (a binary) is a unique value for this fun.
+	    It is calculated from the compiled code for the entire module.</p>
           </item>
           <tag><c>{uniq, Uniq}</c></tag>
           <item>
-            <p><c>Uniq</c> (an integer) is a unique value for this fun.</p>
+            <p><c>Uniq</c> (an integer) is a unique value for this fun.
+	    Starting in the R15 release, this integer is calculated from
+	    the compiled code for the entire module. Before R15, this
+	    integer was based on only the body of the fun.
+	    </p>
           </item>
         </taglist>
       </desc>
diff --git a/erts/emulator/test/code_SUITE.erl b/erts/emulator/test/code_SUITE.erl
index db26655c15..61eeec5ffd 100644
--- a/erts/emulator/test/code_SUITE.erl
+++ b/erts/emulator/test/code_SUITE.erl
@@ -25,7 +25,7 @@
 	 t_check_process_code_ets/1,
 	 external_fun/1,get_chunk/1,module_md5/1,make_stub/1,
 	 make_stub_many_funs/1,constant_pools/1,
-	 false_dependency/1,coverage/1]).
+	 false_dependency/1,coverage/1,fun_confusion/1]).
 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -35,7 +35,7 @@ all() ->
     [new_binary_types, t_check_process_code,
      t_check_process_code_ets, t_check_old_code, external_fun, get_chunk,
      module_md5, make_stub, make_stub_many_funs,
-     constant_pools, false_dependency, coverage].
+     constant_pools, false_dependency, coverage, fun_confusion].
 
 groups() -> 
     [].
@@ -556,6 +556,30 @@ coverage(Config) when is_list(Config) ->
     ?line {'EXIT',{badarg,_}} = (catch erlang:module_loaded(42)),
     ok.
 
+fun_confusion(Config) when is_list(Config) ->
+    Data = ?config(data_dir, Config),
+    Src = filename:join(Data, "fun_confusion"),
+    Mod = fun_confusion,
+
+    %% Load first version of module.
+    compile_load(Mod, Src, 1),
+    F1 = Mod:f(),
+    1 = F1(),
+
+    %% Load second version of module.
+    compile_load(Mod, Src, 2),
+    F2 = Mod:f(),
+
+    %% F1 should refer to the old code, not the newly loaded code.
+    1 = F1(),
+    2 = F2(),
+    ok.
+
+compile_load(Mod, Src, Ver) ->
+    {ok,Mod,Code1} = compile:file(Src, [binary,{d,version,Ver}]),
+    {module,Mod} = code:load_binary(Mod, "fun_confusion.beam", Code1),
+    ok.
+
 %% Utilities.
 
 make_sub_binary(Bin) when is_binary(Bin) ->
diff --git a/erts/emulator/test/code_SUITE_data/fun_confusion.erl b/erts/emulator/test/code_SUITE_data/fun_confusion.erl
new file mode 100644
index 0000000000..16000861df
--- /dev/null
+++ b/erts/emulator/test/code_SUITE_data/fun_confusion.erl
@@ -0,0 +1,31 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2011. 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(fun_confusion).
+
+-export([f/0]).
+
+f() ->
+    fun() -> version() end.
+
+version() ->
+    %% Changing the value returned here should change
+    %% the identity of the fun in f/0.
+    ?version.
+