pixel cache: Allow growing of cache surface

If the new requested surface size is enough larger than the previous
one (but the old is still larger than the absolute minimum),
reallocate it anyway.

This fixes an issue where the text view initially requested a really
small extra size which was then increased but that didn't "take".

diff --git a/gtk/gtkpixelcache.c b/gtk/gtkpixelcache.c
index bffa618d33250d6d391ac5c51b33c3fb01d384d0..fd44f206c406757f6068b17eb1a25115b5a2ef9e 100644 (file)
--- a/gtk/gtkpixelcache.c
+++ b/gtk/gtkpixelcache.c
@@ -26,8 +26,9 @@
    to make scrolling more efficient */
 #define DEFAULT_EXTRA_SIZE 64
 
-/* When resizing viewport to smaller we allow this extra
+/* When resizing viewport we allow this extra
    size to avoid constantly reallocating when resizing */
+#define ALLOW_SMALLER_SIZE 32
 #define ALLOW_LARGER_SIZE 32
 
 struct _GtkPixelCache {
@@ -184,9 +185,9 @@ _gtk_pixel_cache_create_surface_if_needed (GtkPixelCache         *cache,
   /* If current surface can't fit view_rect or is too large, kill it */
   if (cache->surface != NULL &&
       (cairo_surface_get_content (cache->surface) != content ||
-       cache->surface_w < view_rect->width ||
+       cache->surface_w < MAX(view_rect->width, surface_w - ALLOW_SMALLER_SIZE) ||
        cache->surface_w > surface_w + ALLOW_LARGER_SIZE ||
-       cache->surface_h < view_rect->height ||
+       cache->surface_h < MAX(view_rect->height, surface_h - ALLOW_SMALLER_SIZE) ||
        cache->surface_h > surface_h + ALLOW_LARGER_SIZE ||
        cache->surface_scale != gdk_window_get_scale_factor (window)))
     {