[gtk/wip/baedert/for-master] stack: Only compare page names if the new page has one

[Timm Bäder <baedert src gnome org>]

commit 2f65459fcc6f415af5472ceb67486212b8121b57
Author: Timm Bäder <mail baedert org>
Date:   Sat Aug 1 15:26:53 2020 +0200

    stack: Only compare page names if the new page has one

 gtk/gtkstack.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtkstack.c b/gtk/gtkstack.c
index 51a39bfd1f..364def9be5 100644
--- a/gtk/gtkstack.c
+++ b/gtk/gtkstack.c
@@ -1348,14 +1348,17 @@ gtk_stack_add_page (GtkStack     *stack,
 
   g_return_if_fail (child_info->widget != NULL);
 
-  for (l = priv->children; l != NULL; l = l->next)
+  if (child_info->name)
     {
-      GtkStackPage *info = l->data;
-      if (info->name &&
-          g_strcmp0 (info->name, child_info->name) == 0)
+      for (l = priv->children; l != NULL; l = l->next)
         {
-          g_warning ("While adding page: duplicate child name in GtkStack: %s", child_info->name);
-          break;
+          GtkStackPage *info = l->data;
+          if (info->name &&
+              g_strcmp0 (info->name, child_info->name) == 0)
+            {
+              g_warning ("While adding page: duplicate child name in GtkStack: %s", child_info->name);
+              break;
+            }
         }
     }