[vala/0.54] gtkmodule: Improve error message for invalid signal element in ui-file

[Rico Tzschichholz <ricotz src gnome org>]

commit 82676bd3822bbc749fb06688826ae661ab5b5710
Author: Yotam Nachum <me yotam net>
Date:   Sat Nov 6 14:33:07 2021 +0200

    gtkmodule: Improve error message for invalid signal element in ui-file

 codegen/valagtkmodule.vala | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/codegen/valagtkmodule.vala b/codegen/valagtkmodule.vala
index 8b2e88da1..01e60535f 100644
--- a/codegen/valagtkmodule.vala
+++ b/codegen/valagtkmodule.vala
@@ -187,7 +187,13 @@ public class Vala.GtkModule : GSignalModule {
 
                                if (current_class != null) {
                                        if (signal_name == null || handler_name == null) {
-                                               Report.error (node.source_reference, "Invalid signal in ui 
file `%s'", ui_file);
+                                               if (signal_name != null) {
+                                                       Report.error (node.source_reference, "Invalid signal 
`%s' without handler in ui file `%s'", signal_name, ui_file);
+                                               } else if (handler_name != null) {
+                                                       Report.error (node.source_reference, "Invalid signal 
without name in ui file `%s'", ui_file);
+                                               } else {
+                                                       Report.error (node.source_reference, "Invalid signal 
without name and handler in ui file `%s'", ui_file);
+                                               }
                                                current_token = reader.read_token (null, null);
                                                continue;
                                        }