#1054:

* add docstring so we don't break things again in the future
* always verify that the freeze() call has succeeded

git-svn-id: https://xpra.org/svn/Xpra/trunk@11463 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/server/window/window_source.py

@@ -1294,11 +1294,12 @@ def process_damage_region(self, damage_time, window, x, y, w, h, coding, options
         else:
             #schedule encode via queue, after freezing the pixels:
             frozen = image.freeze()
+            assert frozen, "failed to freeze %s" % image
             self.encode_queue.append(item)
             l = len(self.encode_queue)
             if l>=self.encode_queue_max_size:
                 av_delay = 0        #we must free some space!
-            avsynclog("scheduling encode queue iteration in %ims, pixels frozen=%s, encode queue size=%i (max=%i)", av_delay, frozen, l, self.encode_queue_max_size)
+            avsynclog("scheduling encode queue iteration in %ims, encode queue size=%i (max=%i)", av_delay, l, self.encode_queue_max_size)
             self.timeout_add(av_delay, self.call_in_encode_thread, self.encode_from_queue)
 
     def encode_from_queue(self):

src/xpra/x11/bindings/ximage.pyx

@@ -385,6 +385,8 @@ cdef class XImageWrapper:
 
     def restride(self, const int newstride=0):
         #NOTE: this must be called from the UI thread!
+        #passing in a non-zero value must do a restride,
+        #only the default value of 0 may or may not restride
         cdef int rowstride = newstride
         if newstride==0:
             #if not given a newstride, assume it is optional and check if it is worth doing at all: