From 6703828ea9085a4125812cfa47631d061032c514 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 25 Apr 2018 07:41:49 +0200
Subject: sys_core_fold: Eliminate crash for map update in guard

sys_core_fold would crash when attempting to optimize this code:

    t() when (#{})#{}->
        c.
---
 lib/compiler/test/core_fold_SUITE.erl | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

(limited to 'lib/compiler/test')

diff --git a/lib/compiler/test/core_fold_SUITE.erl b/lib/compiler/test/core_fold_SUITE.erl
index 4fd1f84569..ab7f36abf7 100644
--- a/lib/compiler/test/core_fold_SUITE.erl
+++ b/lib/compiler/test/core_fold_SUITE.erl
@@ -27,7 +27,8 @@
 	 multiple_aliases/1,redundant_boolean_clauses/1,
 	 mixed_matching_clauses/1,unnecessary_building/1,
 	 no_no_file/1,configuration/1,supplies/1,
-         redundant_stack_frame/1,export_from_case/1]).
+         redundant_stack_frame/1,export_from_case/1,
+         empty_values/1]).
 
 -export([foo/0,foo/1,foo/2,foo/3]).
 
@@ -47,7 +48,8 @@ groups() ->
        multiple_aliases,redundant_boolean_clauses,
        mixed_matching_clauses,unnecessary_building,
        no_no_file,configuration,supplies,
-       redundant_stack_frame,export_from_case]}].
+       redundant_stack_frame,export_from_case,
+       empty_values]}].
 
 
 init_per_suite(Config) ->
@@ -584,5 +586,17 @@ export_from_case_2(Bool, Rec) ->
     end,
     {ok,Result}.
 
+empty_values(_Config) ->
+    case ?MODULE of
+        core_fold_inline_SUITE ->
+            {'EXIT',_} = (catch do_empty_values());
+        _ ->
+            {'EXIT',{function_clause,_}} = (catch do_empty_values())
+    end,
+    ok.
+
+do_empty_values() when (#{})#{} ->
+    c.
+
 
 id(I) -> I.
-- 
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