[linux] Ensure wxWidgets would use system libpng and not builtin

wxWidgets and webkit must use same libpng version, and webkit is
compiled against system headers so wxWidgets has to use system libpng
too.

external/build_externals_linux.sh

@@ -90,7 +90,7 @@ popd
 # wxwidgets
 pushd wxwidgets
 ./configure --prefix=$output --enable-monolithic=yes --enable-shared=no --enable-unicode --enable-ffile \
-                     --without-libtiff --enable-graphics_ctx $cfg_switches \
+                     --without-libtiff --with-libpng=sys --enable-graphics_ctx $cfg_switches \
                      --disable-largefile CPPFLAGS="$CPPCFLAGS $WXWIDGETS_EXTRA_CFLAGS" &&
     make clean &&
     make &&

external/get_externals_linux.sh

@@ -81,6 +81,7 @@ _extract_and_patch()
   patch tinyxml/tinyxml.h < patches/tinyxml/tinyxml.h.patch
 	echo "---- Applying wxwidget patches ----"
   patch -Np1 -d wxwidgets < patches/wxWidgets-gsock.patch
+  patch -Np1 -d wxwidgets < patches/wxWidgets-r63137.patch
 	echo "---- Applying webkit patches ----"
   patch -Np1 -d webkit < patches/webkit/webkit_688833_to_git_trunk.diff
   patch -Np1 -d webkit < patches/webkit/fully-static.patch

external/patches/wxWidgets-r63137.patch

@@ -0,0 +1,66 @@
+--- wxWidgets/configure.in	2009/12/27 19:40:15	62997
++++ wxWidgets/configure.in	2010/01/12 15:47:16	63137
+@@ -2519,7 +2519,7 @@
+             AC_CHECK_HEADER(png.h,,, [ ])
+
+             if test "$ac_cv_header_png_h" = "yes"; then
+-                AC_CHECK_LIB(png, png_check_sig, PNG_LINK=" -lpng -lz", , [-lz -lm])
++                AC_CHECK_LIB(png, png_sig_cmp, PNG_LINK=" -lpng -lz", , [-lz -lm])
+             fi
+
+             if test "x$PNG_LINK" = "x" ; then
+--- wxwidgets.orig/configure	2010-10-29 23:29:29.812000315 +0400
++++ wxwidgets/configure	2010-10-29 23:30:08.681000043 +0400
+@@ -26379,9 +26379,9 @@
+
+
+             if test "$ac_cv_header_png_h" = "yes"; then
+-                echo "$as_me:$LINENO: checking for png_check_sig in -lpng" >&5
+-echo $ECHO_N "checking for png_check_sig in -lpng... $ECHO_C" >&6
+-if test "${ac_cv_lib_png_png_check_sig+set}" = set; then
++                echo "$as_me:$LINENO: checking for png_sig_cmp in -lpng" >&5
++echo $ECHO_N "checking for png_sig_cmp in -lpng... $ECHO_C" >&6
++if test "${ac_cv_lib_png_png_sig_cmp+set}" = set; then
+   echo $ECHO_N "(cached) $ECHO_C" >&6
+ else
+   ac_check_lib_save_LIBS=$LIBS
+@@ -26399,11 +26399,11 @@
+ #endif
+ /* We use char because int might match the return type of a gcc2
+    builtin and then its argument prototype would still apply.  */
+-char png_check_sig ();
++char png_sig_cmp ();
+ int
+ main ()
+ {
+-png_check_sig ();
++png_sig_cmp ();
+   ;
+   return 0;
+ }
+@@ -26429,20 +26429,20 @@
+   ac_status=$?
+   echo "$as_me:$LINENO: \$? = $ac_status" >&5
+   (exit $ac_status); }; }; then
+-  ac_cv_lib_png_png_check_sig=yes
++  ac_cv_lib_png_png_sig_cmp=yes
+ else
+   echo "$as_me: failed program was:" >&5
+ sed 's/^/| /' conftest.$ac_ext >&5
+
+-ac_cv_lib_png_png_check_sig=no
++ac_cv_lib_png_png_sig_cmp=no
+ fi
+ rm -f conftest.err conftest.$ac_objext \
+       conftest$ac_exeext conftest.$ac_ext
+ LIBS=$ac_check_lib_save_LIBS
+ fi
+-echo "$as_me:$LINENO: result: $ac_cv_lib_png_png_check_sig" >&5
+-echo "${ECHO_T}$ac_cv_lib_png_png_check_sig" >&6
+-if test $ac_cv_lib_png_png_check_sig = yes; then
++echo "$as_me:$LINENO: result: $ac_cv_lib_png_png_sig_cmp" >&5
++echo "${ECHO_T}$ac_cv_lib_png_png_sig_cmp" >&6
++if test $ac_cv_lib_png_png_sig_cmp = yes; then
+   PNG_LINK=" -lpng -lz"
+ fi
+