[FFmpeg-cvslog] configure: make the check for stdatomic.h stricter

[James Almer]

ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Tue Dec 27 21:54:55 2016 -0300| [6993bb4eb6c358c390f674a10f8a8ca69d9ee0fe] | committer: James Almer

configure: make the check for stdatomic.h stricter

Old ICC verions don't advertise having a full C11 implementation but
may nonetheless include a feature-incomplete stdatomic.h header.

Fixes ticket #6049

Signed-off-by: James Almer <jamrial at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6993bb4eb6c358c390f674a10f8a8ca69d9ee0fe
---

 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index d723b8e..56a0b65 100755
--- a/configure
+++ b/configure
@@ -5623,7 +5623,7 @@ check_header asm/types.h
 # it seems there are versions of clang in some distros that try to use the
 # gcc headers, which explodes for stdatomic
 # so we also check that atomics actually work here
-check_builtin stdatomic_h stdatomic.h "atomic_int foo; atomic_store(&foo, 0)"
+check_builtin stdatomic_h stdatomic.h "atomic_int foo, bar = ATOMIC_VAR_INIT(-1); atomic_store(&foo, 0)"
 
 check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
 check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32