fix mask error for BW text, where I forgot to look at just the low-8 bits

trunk/src/core/SkBlitBWMaskTemplate.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkBitmap.h"
@@ skipping 45 matching lines @@
     }
     else
     {
         int left_edge = cx - maskLeft;
         SkASSERT(left_edge >= 0);
         int rite_edge = clip.fRight - maskLeft;
         SkASSERT(rite_edge > left_edge);
 
         int left_mask = 0xFF >> (left_edge & 7);
         int rite_mask = 0xFF << (8 - (rite_edge & 7));
+        rite_mask &= 0xFF;  // only want low-8 bits of mask
         int full_runs = (rite_edge >> 3) - ((left_edge + 7) >> 3);
 
         // check for empty right mask, so we don't read off the end (or go slower than we need to)
         if (rite_mask == 0)
         {
             SkASSERT(full_runs >= 0);
             full_runs -= 1;
             rite_mask = 0xFF;
         }
         if (left_mask == 0xFF)
@@ skipping 44 matching lines @@
         }
     }
 }
 
 #undef SK_BLITBWMASK_NAME
 #undef SK_BLITBWMASK_ARGS
 #undef SK_BLITBWMASK_BLIT8
 #undef SK_BLITBWMASK_GETADDR
 #undef SK_BLITBWMASK_DEVTYPE
 #undef SK_BLITBWMASK_DOROWSETUP