[iagno] Improve checks for appdata-validate, desktop-file-validate, and gtester

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 82d0b0ee6bfc659dc8c7c7fb4b4e7a0416f35672
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Fri Nov 1 08:21:12 2013 -0500

    Improve checks for appdata-validate, desktop-file-validate, and gtester

 configure.ac     |    7 +++++++
 data/Makefile.am |    5 ++++-
 2 files changed, 11 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index fdf3ee8..7306455 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,8 +26,15 @@ PKG_CHECK_MODULES(IAGNO, [
 ])
 
 AC_PATH_PROG(APPDATA_VALIDATE, appdata-validate)
+AM_CONDITIONAL([VALIDATE_APPDATA], [test -n "${APPDATA_VALIDATE}"])
+
 AC_PATH_PROG(DESKTOP_FILE_VALIDATE, desktop-file-validate)
+AM_CONDITIONAL([VALIDATE_DESKTOP_FILE], [test -n "${DESKTOP_FILE_VALIDATE}"])
+
 AC_PATH_PROG(GTESTER, gtester)
+if test -z "${GTESTER}" ; then
+  AC_MSG_ERROR([Please install gtester])
+fi
 
 dnl ###########################################################################
 dnl Internationalization
diff --git a/data/Makefile.am b/data/Makefile.am
index 2d72668..4c3857b 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -48,7 +48,10 @@ CLEANFILES = \
        $(desktop_DATA)
 
 check-local: $(appdata_DATA) $(desktop_DATA)
+if VALIDATE_APPDATA
        $(APPDATA_VALIDATE) $(appdata_DATA)
+endif
+if VALIDATE_DESKTOP_FILE
        $(DESKTOP_FILE_VALIDATE) $(desktop_DATA)
-
+endif
 -include $(top_srcdir)/git.mk