_test_free causes testcase to fail when called with ptr = 0

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What steps will reproduce the problem?
1. Call _test_free with the first argument set to 0 or NULL
2. _test_free asserts that ptr must not be null
3. testcase fails

What is the expected output? What do you see instead?

Since calling free(0) is a no-op in standard C, cmockery should not behave
differently. 

What version of the product are you using? On what operating system?
cmockery-0.1.2 on windows XP using cygwin

Please provide any additional information below.

Original issue reported on code.google.com by ola.nils...@gmail.com on 1 Apr 2010 at 9:42