The effect of the change is pretty minimal though: Previously
"not equal" was returned for unknown formats, now the struct
module figures it out.

memoryobject.c has 100% coverage except for a couple of lines
that are either impossible to reach or very hard to reach.

The new code is among the most heavily exercised lines, since
in test_buffer.py the verify() function always asserts equality.


You can look at the attached memoryobject.c.gcov: *All* failure paths
are taken since Python API functions are wrapped in macros that
set PyExc_FailAPIError and return failure at predefined points
the test suite.