Re: [PATCH v2 01/10] t/test-lib: teach --chain-lint to detect broken &&-chains in subshells

Hi,

Eric Sunshine wrote:

The --chain-lint option detects broken &&-chains by forcing the test to
exit early (as the very first step) with a sentinel value. If that
sentinel is the test's overall exit code, then the &&-chain is intact;
if not, then the chain is broken. Unfortunately, this detection does not
extend to &&-chains within subshells even when the subshell itself is
properly linked into the outer &&-chain.

Address this shortcoming by feeding the body of the test to a
lightweight "linter" which can peer inside subshells and identify broken
&&-chains by pure textual inspection.

Interesting.

                                       Although the linter does not
actually parse shell scripts, it has enough knowledge of shell syntax to
reliably deal with formatting style variations (as evolved over the
years) and to avoid being fooled by non-shell content (such as inside
here-docs and multi-line strings).

This is causing contrib/subtree tests to fail for me: running "make -C
contrib/subtree test" produces

[...]
	*** t7900-subtree.sh ***
	ok 1 - no merge from non-existent subtree
	ok 2 - no pull from non-existent subtree
	ok 3 - add subproj as subtree into sub dir/ with --prefix
	ok 4 - add subproj as subtree into sub dir/ with --prefix and --message
	ok 5 - add subproj as subtree into sub dir/ with --prefix as -P and --message as -m
	ok 6 - add subproj as subtree into sub dir/ with --squash and --prefix and --message
	ok 7 - merge new subproj history into sub dir/ with --prefix
	ok 8 - merge new subproj history into sub dir/ with --prefix and --message
	ok 9 - merge new subproj history into sub dir/ with --squash and --prefix and --message
	ok 10 - merge the added subproj again, should do nothing
	ok 11 - merge new subproj history into subdir/ with a slash appended to the argument of --prefix
	ok 12 - split requires option --prefix
	ok 13 - split requires path given by option --prefix must exist
	ok 14 - split sub dir/ with --rejoin
	ok 15 - split sub dir/ with --rejoin from scratch
	ok 16 - split sub dir/ with --rejoin and --message
	ok 17 - split "sub dir"/ with --branch
	ok 18 - check hash of split
	ok 19 - split "sub dir"/ with --branch for an existing branch
	ok 20 - split "sub dir"/ with --branch for an incompatible branch
	error: bug in the test script: broken &&-chain or run-away HERE-DOC: 
		subtree_test_create_repo "$subtree_test_count" &&
[...]
		)

	Makefile:44: recipe for target 't7900-subtree.sh' failed

The problematic test code looks like this:

	(
		cd "$subtree_test_count/sub proj" &&
		git fetch .. subproj-br &&
		git merge FETCH_HEAD &&

		chks="sub1
sub2
sub3
sub4" &&
		chks_sub=$(cat <<TXT | sed '\''s,^,sub dir/,'\''
$chks
TXT
) &&
		chkms="main-sub1
main-sub2
main-sub3
main-sub4" &&
		chkms_sub=$(cat <<TXT | sed '\''s,^,sub dir/,'\''
$chkms
TXT
) &&

		subfiles=$(git ls-files) &&
		check_equal "$subfiles" "$chkms
$chks"
	)

Ugly quoting, useless use of "cat", etc, aside, I don't think it's
missing any &&.  Hints?

Thanks,
Jonathan