No subject

detects GTK+ when it is either not installed, or not functional due to
a missing pixman. Most recently,

  https://bugs.freedesktop.org/show_bug.cgi?id=29736

This patch makes the configure script more paranoid by

- always using PKG_CHECK_MODULES and not PKG_CHECK_EXISTS, since it
seems PKG_CHECK_EXISTS will sometimes return true even if a dependency
of GTK+, such as pixman-1, is missing.

- explicitly checking that pixman-1 is installed before enabling GTK+.

Cc: my.somewhat.lengthy.loginname at gmail.com
---
 configure.ac |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index d8a8999..dbff2a6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -178,7 +178,6 @@ AC_SUBST(PIXMAN_VERSION_MICRO)
 AC_SUBST(LT_VERSION_INFO)
 
 # Check for dependencies
-#PKG_CHECK_MODULES(DEP, x11)
 
 PIXMAN_CHECK_CFLAG([-Wall])
 PIXMAN_CHECK_CFLAG([-fno-strict-aliasing])
@@ -585,11 +584,18 @@ AC_ARG_ENABLE(gtk,
    [enable_gtk=$enableval], [enable_gtk=auto])
 
 PKG_PROG_PKG_CONFIG
+
+if test $enable_gtk = yes ; then
+   AC_CHECK_LIB([pixman-1], [pixman_version_string])
+   PKG_CHECK_MODULES(GTK, [gtk+-2.0 pixman-1])
+fi
+
 if test $enable_gtk = auto ; then
-   PKG_CHECK_EXISTS([gtk+-2.0], [enable_gtk=yes], [enable_gtk=no])
+   AC_CHECK_LIB([pixman-1], [pixman_version_string], [enable_gtk=auto], [enable_gtk=no])
 fi
-if test $enable_gtk = yes ; then
-   PKG_CHECK_MODULES(GTK, [gtk+-2.0])
+
+if test $enable_gtk = auto ; then
+   PKG_CHECK_MODULES(GTK, [gtk+-2.0 pixman-1], [enable_gtk=yes], [enable_gtk=no])
 fi
 
 AM_CONDITIONAL(HAVE_GTK, [test "x$enable_gtk" = xyes])
-- 
1.7.1.1