In case a download silently failed with no error, check whether the f…

…ile is there before trying to call magic parser on it

pytopo/DownloadTileQueue.py

@@ -6,6 +6,7 @@
 '''
 
 import sys
+import os
 import urllib
 import gobject
 
@@ -89,6 +90,12 @@ def download(url, localpath, callback):
                 print e
                 return None
 
+            # Sometimes there's no error but we still didn't download anything.
+            # Don't try to MIME parse that: magic gets confused by empty files.
+            if not os.path.exists(localpath):
+                print "Failed to download", url, "to", localpath
+                return None
+
             if magic_parser is None:
                 try:
                     import magic

pytopo/MapWindow.py

@@ -1349,7 +1349,7 @@ def draw_pixbuf(self, pixbuf, x_off, y_off, x, y, w, h):
         # Sometimes the next line prints:
         # GtkWarning: gdk_drawable_real_draw_pixbuf: assertion 'width >= 0 && height >= 0' failed
         # but checking width and height doesn't seem to guard against that.
-        # What does?
+        # What does? This doesn't:
         # print "Drawing pixbuf that is %d x %d!" \
         #     % (pixbuf.get_width(), pixbuf.get_height())
         # if (pixbuf.get_width() <= 0 or pixbuf.get_height() <= 0):