Re: [PATCHv2 4/6] t7510: exit for loop with test result

Jeff King venit, vidit, dixit 13.06.2014 13:46:

On Fri, Jun 13, 2014 at 12:42:46PM +0200, Michael J Gruber wrote:

quoted

When t7510 was introduced, the author made sure that a for loop in
a subshell would return with the appropriate error code.

Make sure this is true also the for the first line in each loop, which
was missed.

Signed-off-by: Michael J Gruber <redacted>
---
 t/t7510-signed-commit.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 5ddac1a..a5ba48e 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh

@@ -49,7 +49,7 @@ test_expect_success GPG 'show signatures' '
 	(
 		for commit in initial second merge fourth-signed fifth-signed sixth-signed master
 		do
-			git show --pretty=short --show-signature $commit >actual &&
+			git show --pretty=short --show-signature $commit >actual || exit 1
 			grep "Good signature from" actual || exit 1

Hrm. The original is:

  X &&
  Y || exit 1

Won't that still exit (i.e., it is already correct)? Doing:

  for X in true false; do
    for Y in true false; do
      ($X && $Y || exit 1)
      echo "$X/$Y: $?"
    done
  done

yields:

  true/true: 0
  true/false: 1
  false/true: 1
  false/false: 1

(and should still short-circuit Y, because we go from left-to-right).

I do not mind changing it to keep the style of each line consistent,
though. I would have written it as a series of "&&"-chains, with a
single exit at the end, but I think that is just a matter of preference.

If I remember correctly, I put something failing on the first line of
the original version, and the test succeeded. I think the point is that
we have a for loop in a subshell, and we need to make sure that the
false of one iteration is not overwritten by the true of the next one -
"exit 1" makes sure to "break" the for loop and exit the subshell.
(The chain should do that as well, I'll recheck.)

Michael