[gnome-subtitles] Fallback to gtk3 when gtk2 not found

[Pedro Daniel da Rocha Melo e Castro <pcastro src gnome org>]

commit 0b2442102413aa446ce1b53d3f1c57c6fafee339
Author: Pedro Castro <pedro gnomesubtitles org>
Date:   Sat Mar 10 10:56:21 2012 +0000

    Fallback to gtk3 when gtk2 not found

 configure.ac  |    4 +++-
 m4/gtk-doc.m4 |    6 ++++++
 2 files changed, 9 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index cc68439..d9c40a2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -70,7 +70,9 @@ AC_SUBST(gstreamer_LIBS)
 
 PKG_CHECK_MODULES(MONO, mono >= $MONO_REQUIRED_VERSION)
 PKG_CHECK_MODULES(GTKSHARP, gtk-sharp-2.0 glade-sharp-2.0 gconf-sharp-2.0 >= $GTKSHARP_REQUIRED_VERSION)
-PKG_CHECK_MODULES(GTK, gtk+-2.0 >= $GTK_REQUIRED_VERSION)
+PKG_CHECK_MODULES(GTK, gtk+-2.0 >= $GTK_REQUIRED_VERSION,, [
+	PKG_CHECK_MODULES(GTK, gtk+-3.0 >= $GTK_REQUIRED_VERSION)
+])
 
 dnl Check gtk-sharp version
 PKG_CHECK_MODULES(GTKSHARP_INVALID, gtk-sharp-2.0 >= 2.12.2 gtk-sharp-2.0 <= 2.12.6, gtksharp_invalid=true, gtksharp_invalid=false)
diff --git a/m4/gtk-doc.m4 b/m4/gtk-doc.m4
index 2cfa1e7..0ada151 100644
--- a/m4/gtk-doc.m4
+++ b/m4/gtk-doc.m4
@@ -6,6 +6,7 @@ dnl Usage:
 dnl   GTK_DOC_CHECK([minimum-gtk-doc-version])
 AC_DEFUN([GTK_DOC_CHECK],
 [
+  AC_REQUIRE([PKG_PROG_PKG_CONFIG])
   AC_BEFORE([AC_PROG_LIBTOOL],[$0])dnl setup libtool first
   AC_BEFORE([AM_PROG_LIBTOOL],[$0])dnl setup libtool first
 
@@ -33,6 +34,11 @@ AC_DEFUN([GTK_DOC_CHECK],
                         AC_MSG_ERROR([gtk-doc not installed and --enable-gtk-doc requested]))],
       [PKG_CHECK_EXISTS([gtk-doc >= $1],,
                         AC_MSG_ERROR([You need to have gtk-doc >= $1 installed to build $PACKAGE_NAME]))])
+    dnl don't check for glib if we build glib
+    if test "x$PACKAGE_NAME" != "xglib"; then
+      dnl don't fail if someone does not have glib
+      PKG_CHECK_MODULES(GTKDOC_DEPS, glib-2.0 >= 2.10.0 gobject-2.0  >= 2.10.0,,)
+    fi
   fi
 
   AC_MSG_CHECKING([whether to build gtk-doc documentation])