tests: use pdiff instead of diff for portability
"diff" command might cause redundant message, "No differences
encountered" on Solaris for example. But suppressing option like "-q"
isn't portable, because POSIX specification doesn't define it.
pdiff script was introduced by b59ef0c21405 to stabilize output of
standard diff command on each platforms.
fixbundle() {
grep -v 'saving bundle' | grep -v 'saved backup' | \
grep -v added | grep -v adding | \
grep -v "unable to find 'e' for patching" | \
grep -v "e: No such file or directory" | \
cat
}