31 lines
		
	
	
		
			873 B
		
	
	
	
		
			Python
		
	
	
	
			
		
		
	
	
			31 lines
		
	
	
		
			873 B
		
	
	
	
		
			Python
		
	
	
	
| #
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| # The various methods of bufferobject.c (here buffer_subscript()) call
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| # get_buf() before calling potentially more Python code (here via
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| # PySlice_GetIndicesEx()).  But get_buf() already returned a void*
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| # pointer.  This void* pointer can become invalid if the object
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| # underlying the buffer is mutated (here a bytearray object).
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| #
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| # As usual, please keep in mind that the three "here" in the sentence
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| # above are only examples.  Each can be changed easily and lead to
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| # another crasher.
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| #
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| # This crashes for me on Linux 32-bits with CPython 2.6 and 2.7
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| # with a segmentation fault.
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| #
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| 
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| 
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| class PseudoIndex(object):
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|     def __index__(self):
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|         for c in "foobar"*n:
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|             a.append(c)
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|         return n * 4
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| 
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| 
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| for n in range(1, 100000, 100):
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|     a = bytearray("test"*n)
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|     buf = buffer(a)
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| 
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|     s = buf[:PseudoIndex():1]
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|     #print repr(s)
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|     #assert s == "test"*n
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