[gtk/font-rendering-demo-3] Small fixes

[Matthias Clasen <matthiasc src gnome org>]

commit 8740690ecbab691bee29a98b907fe87c43a4ddc2
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Jul 28 10:47:20 2018 -0400

    Small fixes
    
    Avoid a crash, and fix the title capitalization.

 demos/gtk-demo/fontrendering.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/demos/gtk-demo/fontrendering.c b/demos/gtk-demo/fontrendering.c
index e54f2cb163..de7dc31c84 100644
--- a/demos/gtk-demo/fontrendering.c
+++ b/demos/gtk-demo/fontrendering.c
@@ -1,4 +1,4 @@
-/* Pango/Font rendering
+/* Pango/Font Rendering
  *
  * Demonstrates variations in font rendering.
  */
@@ -82,7 +82,9 @@ update_image (void)
 
       pango_extents_to_pixels (&logical, NULL);
 
-      surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, logical.width, logical.height);
+      surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                            MAX(1,logical.width),
+                                            MAX(1,logical.height));
       cr = cairo_create (surface);
       cairo_set_source_rgb (cr, 1, 1, 1);
       cairo_paint (cr);
@@ -109,7 +111,9 @@ update_image (void)
       iter = pango_layout_get_iter (layout);
       run = pango_layout_iter_get_run (iter);
 
-      surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, logical.width * 3 / 2, 4*logical.height);
+      surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                            MAX(1, logical.width) * 3 / 2,
+                                            MAX(1, logical.height) * 4);
       cr = cairo_create (surface);
       cairo_set_source_rgb (cr, 1, 1, 1);
       cairo_paint (cr);