resolved conflicts for merge of 8787cd6d to mnc-dev

Change-Id: I19497d05a021c21c905b2bddd5b36d370dc2208f

diff --cc tools/releasetools/sparse_img.py
index 49b3a67,78f3057..7019f00
--- 1/tools/releasetools/sparse_img.py
--- 2/tools/releasetools/sparse_img.py
+++ b/tools/releasetools/sparse_img.py
@@@ -221,9 -201,12 +221,14 @@@ class SparseImage(object)
            nonzero_blocks.append(b)
            nonzero_blocks.append(b+1)
  
-     out["__ZERO"] = rangelib.RangeSet(data=zero_blocks)
-     out["__NONZERO"] = rangelib.RangeSet(data=nonzero_blocks)
-     out["__COPY"] = clobbered_blocks
 -    assert zero_blocks or nonzero_blocks
++    assert zero_blocks or nonzero_blocks or clobbered_blocks
+ 
+     if zero_blocks:
+       out["__ZERO"] = rangelib.RangeSet(data=zero_blocks)
+     if nonzero_blocks:
+       out["__NONZERO"] = rangelib.RangeSet(data=nonzero_blocks)
++    if clobbered_blocks:
++      out["__COPY"] = clobbered_blocks
  
    def ResetFileMap(self):
      """Throw away the file map and treat the entire image as