On Thu, Nov 09, 2023 at 01:55:15PM -0500, Jeff King wrote:

On Thu, Nov 09, 2023 at 11:53:35AM +0100, Patrick Steinhardt wrote:

quoted

Functions in git-subtree.sh all assert that they are being passed the
correct number of arguments. In cases where we accept a variable number
of arguments we assert this via a single call to `test` with `-o`, which
is discouraged by our coding guidelines.

Convert these cases to stop doing so.

OK. I think these ones really are safe, because they're only expanding
$#, but I agree with the principle to follow the guidelines.

quoted

 # Usage: process_subtree_split_trailer SPLIT_HASH MAIN_HASH [REPOSITORY]
 process_subtree_split_trailer () {
-	assert test $# = 2 -o $# = 3
+	assert test $# -ge 2
+	assert test $# -le 3

It took me a minute to figure out why we were swapping "=" for "-ge". It
is because we want to logical-OR the two conditions, but "assert"
requires that we test one at a time. I think that is probably worth
explaining in the commit message.

I really hate to admit how long I've pondered over this patch series in
total, up to the point where I did a `git rebase --reset-author-date` at
the end just so that it's not obvious. So I totally get everyone who
needs to stop and think for a bit here.

Will adapt the commit message.

Patrick

quoted

@@ -916,7 +919,7 @@ cmd_split () {
 	if test $# -eq 0
 	then
 		rev=$(git rev-parse HEAD)
-	elif test $# -eq 1 -o $# -eq 2
+	elif test $# -eq 1 || test $# -eq 2

OK, this one is a straight-forward use of "||".

quoted

 cmd_merge () {
-	test $# -eq 1 -o $# -eq 2 ||
+	if test $# -lt 1 || test $# -gt 2
+	then
 		die "fatal: you must provide exactly one revision, and optionally a repository. Got: '$*'"
+	fi
+

But here we swap "-eq" for other operators. We have to because we went
from "||" to an "if". I think what you have here is correct, but you
could also write:

  if ! { test $# -eq 1 || test $# -eq 2; }

(I am OK with either, it just took me a minute to verify that your
conversion was correct. But that is a one-time issue now while
reviewing, and I think the code is readable going forward).