[vala/tintou/glib-version-message] vala: Trigger understandable errors with GLib target version

[Corentin Noël <corentinnoel src gnome org>]

commit a9b05fa9008e4cc6d60d8e86d2a0af2244d7282f
Author: Corentin Noël <corentin elementary io>
Date:   Mon Dec 3 11:38:07 2018 +0100

    vala: Trigger understandable errors with GLib target version

 vala/valacodecontext.vala | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/vala/valacodecontext.vala b/vala/valacodecontext.vala
index 815899cee..9b835e13c 100644
--- a/vala/valacodecontext.vala
+++ b/vala/valacodecontext.vala
@@ -555,9 +555,12 @@ public class Vala.CodeContext {
                int glib_major = target_glib_major;
                int glib_minor = target_glib_minor;
 
-               if (target_glib != null && target_glib.scanf ("%d.%d", out glib_major, out glib_minor) != 2
-                   || glib_minor % 2 != 0) {
-                       Report.error (null, "Invalid format or version for target GLib");
+               if (target_glib != null && target_glib.scanf ("%d.%d", out glib_major, out glib_minor) != 2) {
+                       Report.error (null, "Invalid format for target GLib, it should be MAJOR.MINOR");
+               }
+
+               if (glib_minor % 2 != 0) {
+                       Report.error (null, "Invalid version for target GLib, only stable versions (with even 
minor number) are supported");
                }
 
                if (glib_major != 2) {