[Bug c++/51459] [4.7 Regression] 'double free or corruption' involving std::function and lambdas

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51459

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-08 11:55:48 UTC ---
Indeed, with 4.6.x preprocessed source for the reduced testcase this started
failing with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175158 aka
PR43912.

The only important difference at *.gimple level (except for renaming arguments
and similar debug info only related changes) seems to be:

-animate(F) [with F = std::function<void()>]::<lambda()> (const struct
__lambda0 * this)
+animate(F) [with F = std::function<void()>]::<lambda()> (const struct
__lambda0 * __closure)
 {
-  const struct function * D.9363;
+  const struct function * D.9367;
+  const struct function * D.9368;
+  const struct function f [value-expr: __closure->__f];

-  D.9363 = &this->__f;
-  std::function<void()>::operator() (D.9363);
+  try
+    {
+      D.9367 = &__closure->__f;
+      std::function<void()>::operator() (D.9367);
+    }
+  finally
+    {
+      D.9368 = &__closure->__f;
+      std::function<void()>::~function (D.9368);
+    }
 }

so before this change __closure->__f wouldn't be destructed, now it is, and
supposedly it is destructed in the caller too.