--- a/src/lib/cache.c	Tue Dec 29 15:34:09 2009 +0200
+++ b/src/lib/cache.c	Tue Dec 29 15:34:18 2009 +0200
@@ -411,8 +411,8 @@
  */
 static inline void tile_row_fill_clip (struct pt_cache *cache, png_byte *row, size_t width_px)
 {
-    // XXX: use a defined background color, or full transparency?
-    memset(row, 0, width_px * cache->header->col_bytes);
+    // XXX: use a configureable background color, or full transparency?
+    memset(row, /* 0xd7 */ 0x00, width_px * cache->header->col_bytes);
 }
 
 /**

--- a/src/lib/cache.h	Tue Dec 29 15:34:09 2009 +0200
+++ b/src/lib/cache.h	Tue Dec 29 15:34:18 2009 +0200
@@ -54,7 +54,7 @@
     /** Number of png_color entries that follow */
     uint16_t num_palette;
 
-    /** Convenience field for number of bytes per row */
+    /** Number of bytes per row */
     uint32_t row_bytes;
     
     /** Number of bytes per pixel */

--- a/src/lib/pngtile.h	Tue Dec 29 15:34:09 2009 +0200
+++ b/src/lib/pngtile.h	Tue Dec 29 15:34:18 2009 +0200
@@ -20,12 +20,12 @@
 struct pt_image;
 
 /** Bitmask for pt_image_open modes */
-enum pt_image_mode {
+enum pt_open_mode {
     /** Update cache if needed */
     PT_OPEN_UPDATE   = 0x01,
 
     /** Accept stale cache */
-    PT_OPEN_STALE    = 0x02,
+    // TODO: PT_OPEN_STALE    = 0x02,
 };
 
 /**