These "expect-failure" tests were not looking for the right string
in the patch file. For example:
grep "^ *"S. E. Cipient" <scipient@example.com>\$" patch5
was looking for "^ *S." in these three files:
"E."
"Cipient <scipient@example.com>$"
"patch5"
With some implementations of grep, the lack of file "E." was
reported as an error, leading to the failure of the test.
With other implementations of grep, the pattern "^ *S." matched what
was in patch5, without diagnosing the missing files as an error, and
made these tests unexpectedly pass.