build: Pass ZLIB_CFLAGS for gio build

Otherwise we will fail if zlib is in an alternative prefix.

Commit message written by Colin Walters <walters@verbum.org>

https://bugzilla.gnome.org/show_bug.cgi?id=655769

diff --git a/gio/Makefile.am b/gio/Makefile.am
index 148f4c5..295c60d 100644 (file)
--- a/gio/Makefile.am
+++ b/gio/Makefile.am
@@ -415,6 +415,8 @@ libgio_2_0_la_LIBADD = \
        $(XATTR_LIBS)                                   \
        $(NULL)
 
+libgio_2_0_la_CPPFLAGS = $(ZLIB_CFLAGS) $(AM_CPPFLAGS)
+
 if PLATFORM_WIN32
 no_undefined = -no-undefined
 endif