configure: Provide more helpful message if libvte not present

If the system has GTK but not libvte, it's more helpful to
tell the user that libvte is missing than to simply say that
GTK is not present.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1374162121-31582-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/configure b/configure
index cb0f870..9e1cd19 100755
--- a/configure
+++ b/configure
@@ -1697,19 +1697,23 @@
       vtepackage="vte"
       vteversion="0.24.0"
     fi
-    if $pkg_config --exists "$gtkpackage >= $gtkversion" && \
-       $pkg_config --exists "$vtepackage >= $vteversion"; then
+    if ! $pkg_config --exists "$gtkpackage >= $gtkversion"; then
+        if test "$gtk" = "yes" ; then
+            feature_not_found "gtk"
+        fi
+        gtk="no"
+    elif ! $pkg_config --exists "$vtepackage >= $vteversion"; then
+        if test "$gtk" = "yes" ; then
+            error_exit "libvte not found (required for gtk support)"
+        fi
+        gtk="no"
+    else
 	gtk_cflags=`$pkg_config --cflags $gtkpackage 2>/dev/null`
 	gtk_libs=`$pkg_config --libs $gtkpackage 2>/dev/null`
 	vte_cflags=`$pkg_config --cflags $vtepackage 2>/dev/null`
 	vte_libs=`$pkg_config --libs $vtepackage 2>/dev/null`
 	libs_softmmu="$gtk_libs $vte_libs $libs_softmmu"
 	gtk="yes"
-    else
-	if test "$gtk" = "yes" ; then
-	    feature_not_found "gtk"
-	fi
-	gtk="no"
     fi
 fi