Junio C Hamano venit, vidit, dixit 05.07.2017 18:26: > Johannes Schindelin <johannes.schindelin@xxxxxx> writes: > >> It seems to be a little-known feature of `grep` (and it certainly came >> as a surprise to this here developer who believed to know the Unix tools >> pretty well) that multiple patterns can be passed in the same >> command-line argument simply by separating them by newlines. Watch, and >> learn: >> >> $ printf '1\n2\n3\n' | grep "$(printf '1\n3\n')" >> 1 >> 3 >> >> That behavior also extends to patterns passed via `-e`, and it is not >> modified by passing the option `-E` (but trying this with -P issues the >> error "grep: the -P option only supports a single pattern"). >> >> It seems that there are more old Unix hands who are surprised by this >> behavior, as grep invocations of the form >> >> grep "$(git rev-parse A B) C" file >> >> were introduced in a85b377d041 (push: the beginning of "git push >> --signed", 2014-09-12), and later faithfully copy-edited in b9459019bbb >> (push: heed user.signingkey for signed pushes, 2014-10-22). >> >> Please note that the output of `git rev-parse A B` separates the object >> IDs via *newlines*, not via spaces, and those newlines are preserved >> because the interpolation is enclosed in double quotes. >> >> As a consequence, these tests try to validate that the file contains >> either A's object ID, or B's object ID followed by C, or both. Clearly, >> however, what the test wanted to see is that there is a line that >> contains all of them. >> >> This is clearly unintended, and the grep invocations in question really >> match too many lines. >> >> Fix the test by avoiding the newlines in the patterns. >> >> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> >> --- > > The invocation this fixes is not just misleading but simply wrong. > Nicely spotted. In addition, the patch makes sure to catch any rev-parse failures which the original invocation shove under the rug. > Thanks, will queue. Thanks from the faithful copy-editor ;) How did you spot this? Are there grep versions that behave differently? >> t/t5534-push-signed.sh | 14 ++++++++++---- >> 1 file changed, 10 insertions(+), 4 deletions(-) >> >> diff --git a/t/t5534-push-signed.sh b/t/t5534-push-signed.sh >> index 5bcb288f5c4..464ffdd147a 100755 >> --- a/t/t5534-push-signed.sh >> +++ b/t/t5534-push-signed.sh >> @@ -119,8 +119,11 @@ test_expect_success GPG 'signed push sends push certificate' ' >> sed -n -e "s/^nonce /NONCE=/p" -e "/^$/q" dst/push-cert >> ) >expect && >> >> - grep "$(git rev-parse noop ff) refs/heads/ff" dst/push-cert && >> - grep "$(git rev-parse noop noff) refs/heads/noff" dst/push-cert && >> + noop=$(git rev-parse noop) && >> + ff=$(git rev-parse ff) && >> + noff=$(git rev-parse noff) && >> + grep "$noop $ff refs/heads/ff" dst/push-cert && >> + grep "$noop $noff refs/heads/noff" dst/push-cert && >> test_cmp expect dst/push-cert-status >> ' >> >> @@ -200,8 +203,11 @@ test_expect_success GPG 'fail without key and heed user.signingkey' ' >> sed -n -e "s/^nonce /NONCE=/p" -e "/^$/q" dst/push-cert >> ) >expect && >> >> - grep "$(git rev-parse noop ff) refs/heads/ff" dst/push-cert && >> - grep "$(git rev-parse noop noff) refs/heads/noff" dst/push-cert && >> + noop=$(git rev-parse noop) && >> + ff=$(git rev-parse ff) && >> + noff=$(git rev-parse noff) && >> + grep "$noop $ff refs/heads/ff" dst/push-cert && >> + grep "$noop $noff refs/heads/noff" dst/push-cert && >> test_cmp expect dst/push-cert-status >> ' >> >> >> base-commit: 5116f791c12dda6b6c22fa85b600a8e30dfa168a
