Merge commit '056fd4fe65e70b4dbca97bcf7faf8b7ce3df993f'

* commit '056fd4fe65e70b4dbca97bcf7faf8b7ce3df993f':
  configure: Properly check for availability of -Wno-foo warning flags

Conflicts:
	configure

Merged-by: Michael Niedermayer <michaelni@gmx.at>

diff --cc configure
index e29cd12,88e7058..e868535
--- 1/configure
--- 2/configure
+++ b/configure
@@@ -4428,10 -3906,7 +4428,6 @@@ check_cflags -Wal
  check_cflags -Wdisabled-optimization
  check_cflags -Wpointer-arith
  check_cflags -Wredundant-decls
- check_cflags -Wno-pointer-sign
 -check_cflags -Wcast-qual
  check_cflags -Wwrite-strings
  check_cflags -Wtype-limits
  check_cflags -Wundef
@@@ -4440,9 -3914,20 +4436,20 @@@ check_cflags -Wno-pointer-to-int-cas
  check_cflags -Wstrict-prototypes
  enabled extra_warnings && check_cflags -Winline
  
+ check_disable_warning(){
+     warning_flag=-W${1#-Wno-}
+     test_cflags $warning_flag && add_cflags $1
+ }
+ 
+ check_disable_warning -Wno-parentheses
+ check_disable_warning -Wno-switch
+ check_disable_warning -Wno-format-zero-length
+ check_disable_warning -Wno-pointer-sign
+ enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
+ 
  # add some linker flags
  check_ldflags -Wl,--warn-common
 -check_ldflags -Wl,-rpath-link=libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
 +check_ldflags -Wl,-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
  test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic
  
  enabled xmm_clobber_test &&
@@@ -4537,8 -4013,8 +4544,7 @@@ elif enabled gcc; the
      check_cflags -Werror=implicit-function-declaration
      check_cflags -Werror=missing-prototypes
      check_cflags -Werror=return-type
 -    check_cflags -Werror=declaration-after-statement
      check_cflags -Werror=vla
-     enabled extra_warnings || check_cflags -Wno-maybe-uninitialized
  elif enabled llvm_gcc; then
      check_cflags -mllvm -stack-alignment=16
  elif enabled clang; then