tests: escape bytes setting MSB in input of grep for portability GNU grep (2.21-2 or later) assumes that input is encoded in LC_CTYPE, and input is binary if it contains byte sequence not valid for that encoding. For example, if locale is configured as C, a byte setting most significant bit (MSB) makes such GNU grep show "Binary file <FILENAME> matches" message instead of matched lines unintentionally. This behavior is recognized as a bug, and fixed in GNU grep 2.25-1 or later. But some distributions are shipped with such buggy version (e.g. Ubuntu xenial, which is used by launchpad buildbot). http://debbugs.gnu.org/cgi/bugreport.cgi?bug=19230 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800670 http://packages.ubuntu.com/xenial/grep This causes failure of test-commit-interactive.t, which applies grep on CP932 byte sequence since 1111e84de635. But, explicit setting LC_CTYPE for CP932 might cause another problem, because it can't be assumed that all environment running Mercurial tests allows arbitrary locale setting. To resolve this issue, this patch escapes bytes setting MSB in input of grep. For this purpose: - str.encode('string-escape') isn't useful, because it escapes also control code (less than 0x20), and makes EOL handling complicated - "f --hexdump" isn't useful, because it isn't line-oriented - "sed -n" seems reasonable, but "sed" itself sometimes causes portability issue, too (e.g. 900767dfa80d or afb86ee925bf) This patch is posted with "stable" flag, because 1111e84de635 is on stable branch.