[gtk] textlayout: Allow querying empty areas

[Benjamin Otte <otte src gnome org>]

commit 4b07d2815375856823532b2238d87455c3be2f7c
Author: Benjamin Otte <otte redhat com>
Date:   Fri Mar 29 00:24:00 2019 +0100

    textlayout: Allow querying empty areas
    
    This only happens when the textview has no content, but it does happen
    now that such a textview gets allocated 0x0 and not 1x1.

 gtk/gtktextlayout.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtktextlayout.c b/gtk/gtktextlayout.c
index 51ac51a3b6..7947eadcf8 100644
--- a/gtk/gtktextlayout.c
+++ b/gtk/gtktextlayout.c
@@ -722,7 +722,9 @@ gtk_text_layout_get_lines (GtkTextLayout *layout,
   GSList *retval;
 
   g_return_val_if_fail (GTK_IS_TEXT_LAYOUT (layout), NULL);
-  g_return_val_if_fail (bottom_y > top_y, NULL);
+
+  if (top_y <= bottom_y)
+    return NULL;
 
   retval = NULL;