[PATCH 2/5] t7510: use consistent &&-chains in loop

From: Michael J Gruber <git@drmicha.warpmail.net>

We check multiple commits in a loop. Because we want to break out of the loop if any single iteration fails, we use a subshell/exit like:

  (
	for i in $stuff
	do
		do-something $i || exit 1
	done
  )

However, we are inconsistent in our loop body. Some commands get their own "|| exit 1", and others try to chain to the next command with "&&", like:

  X &&
  Y || exit 1
  Z || exit 1

This is a little hard to read and follow, because X and Y are treated differently for no good reason. But much worse, the second loop follows a similar pattern and gets it wrong. "Y" is expected to fail, so we use "&& exit 1", giving us:

  X &&
  Y && exit 1
  Z || exit 1

That gets the test for X wrong (we do not exit unless both X fails and Y unexpectedly succeeds, but we would want to exit if _either_ is wrong). We can write this clearly and correctly by consistently using "&&", followed by a single "|| exit 1", and negating Y with "!" (as we would in a normal &&-chain). Like:

  X &&
  ! Y &&
  Z || exit 1

Signed-off-by: Jeff King <peff@peff.net>
---
I listed Michael as the author here, because this is the patch that I
expected to come in his next re-roll, based on our discussion. I'm
including it here because I'm about to touch the same area (and Michael,
you'd probably want to rebase on top of this series anyway. Assuming I
haven't screwed it up :) ).

 t/t7510-signed-commit.sh | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)