[network-manager-applet/nma-1-0: 2/6] build: fix detecting support for -Wno-* compiler flags

[Thomas Haller <thaller src gnome org>]

commit 82eb252bab08ca785c2238a380a1b40a1e45cb50
Author: Thomas Haller <thaller redhat com>
Date:   Tue Feb 24 18:11:21 2015 +0100

    build: fix detecting support for -Wno-* compiler flags
    
    Since GCC 4.4, gcc does not warn about unknown -Wno-* flags. At
    least, it does not warning unless another warning is raised as well
    (https://gcc.gnu.org/wiki/FAQ#wnowarning).
    
    We didn't notice up to now, because we only tested flags that GCC
    actually supports.
    
    Hack around this, by checking for the -W* counterpart instead.
    
    Taken from NetworkManager, commit 0462104317bfc097a90707a13590248707324846.
    
    (cherry picked from commit c090c3a3319b657b323dd2a3e681961e94ce1346)

 m4/compiler_warnings.m4 |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/m4/compiler_warnings.m4 b/m4/compiler_warnings.m4
index 3fe8293..97897e4 100644
--- a/m4/compiler_warnings.m4
+++ b/m4/compiler_warnings.m4
@@ -30,7 +30,8 @@ if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
                      -Wundef -Wimplicit-function-declaration \
                      -Wpointer-arith -Winit-self \
                      -Wmissing-include-dirs -Waggregate-return; do
-               CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS_EXTRA $option $CFLAGS_SAVED"
+               dnl GCC 4.4 does not warn when checking for -Wno-* flags 
(https://gcc.gnu.org/wiki/FAQ#wnowarning)
+               CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS_EXTRA $(printf '%s' "$option" | sed 's/^-Wno-/-W/')  
$CFLAGS_SAVED"
                AC_MSG_CHECKING([whether gcc understands $option])
                AC_TRY_COMPILE([], [],
                        has_option=yes,