[PATCH] t3070: skip ls-files tests with backslash patterns on Windows

[PATCH] t3070: skip ls-files tests with backslash patterns on Windows

[Kristofer Karlsson via GitGitGadget]

From: Kristofer Karlsson <krka@spotify.com>

On Windows (MINGW), backslashes in pathspecs are silently converted to
forward slashes (directory separators), which changes the glob semantics.
This causes 36 test failures in t3070-wildmatch when the "via ls-files"
variants test patterns containing backslash escapes (e.g. '\[ab]',
'[\-_]', '[A-\\]').

The wildmatch function itself handles these patterns correctly — only the
ls-files code path fails because pathspec parsing converts the
backslashes before they reach the glob matcher.

Skip these ls-files tests on platforms where BSLASHPSPEC is not set,
which is the existing prereq that captures exactly this semantic:
"backslashes in pathspec are not directory separators."

Signed-off-by: Kristofer Karlsson <krka@spotify.com>
---
    t3070: skip ls-files tests with backslash patterns on Windows
    
    On Windows (MINGW), backslashes in pathspecs are silently converted to
    forward slashes (directory separators), which changes the glob
    semantics. This causes 36 test failures in t3070-wildmatch when the "via
    ls-files" variants test patterns containing backslash escapes (e.g.
    \[ab], [\-_], [A-\\]).
    
    The wildmatch function itself handles these patterns correctly — only
    the ls-files code path fails because pathspec parsing converts the
    backslashes before they reach the glob matcher.
    
    Skip these ls-files tests on platforms where BSLASHPSPEC is not set,
    which is the existing prereq that captures exactly this semantic:
    "backslashes in pathspec are not directory separators."

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2128%2Fspkrka%2Fwildmatch-windows-fix-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2128/spkrka/wildmatch-windows-fix-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/2128

 t/t3070-wildmatch.sh | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/t/t3070-wildmatch.sh b/t/t3070-wildmatch.sh
index 655bb1a0f2..3394122218 100755
--- a/t/t3070-wildmatch.sh
+++ b/t/t3070-wildmatch.sh
@@ -99,6 +99,13 @@ match_with_ls_files() {
 	match_function=$4
 	ls_files_args=$5
 
+	prereqs=EXPENSIVE_ON_WINDOWS
+	case "$pattern" in
+	*\\*)
+		prereqs="$prereqs,BSLASHPSPEC"
+		;;
+	esac
+
 	match_stdout_stderr_cmp="
 		tr -d '\0' <actual.raw >actual &&
 		test_must_be_empty actual.err &&
@@ -108,36 +115,36 @@ match_with_ls_files() {
 	then
 		if test -e .git/created_test_file
 		then
-			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match dies on '$pattern' '$text'" "
+			test_expect_success $prereqs "$match_function (via ls-files): match dies on '$pattern' '$text'" "
 				printf '%s' '$text' >expect &&
 				test_must_fail git$ls_files_args ls-files -z -- '$pattern'
 			"
 		else
-			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
+			test_expect_failure $prereqs "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
 		fi
 	elif test "$match_expect" = 1
 	then
 		if test -e .git/created_test_file
 		then
-			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match '$pattern' '$text'" "
+			test_expect_success $prereqs "$match_function (via ls-files): match '$pattern' '$text'" "
 				printf '%s' '$text' >expect &&
 				git$ls_files_args ls-files -z -- '$pattern' >actual.raw 2>actual.err &&
 				$match_stdout_stderr_cmp
 			"
 		else
-			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
+			test_expect_failure $prereqs "$match_function (via ls-files): match skip '$pattern' '$text'" 'false'
 		fi
 	elif test "$match_expect" = 0
 	then
 		if test -e .git/created_test_file
 		then
-			test_expect_success EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): no match '$pattern' '$text'" "
+			test_expect_success $prereqs "$match_function (via ls-files): no match '$pattern' '$text'" "
 				>expect &&
 				git$ls_files_args ls-files -z -- '$pattern' >actual.raw 2>actual.err &&
 				$match_stdout_stderr_cmp
 			"
 		else
-			test_expect_failure EXPENSIVE_ON_WINDOWS "$match_function (via ls-files): no match skip '$pattern' '$text'" 'false'
+			test_expect_failure $prereqs "$match_function (via ls-files): no match skip '$pattern' '$text'" 'false'
 		fi
 	else
 		test_expect_success "PANIC: Test framework error. Unknown matches value $match_expect" 'false'

base-commit: c69baaf57ba26cf117c2b6793802877f19738b0d
-- 
gitgitgadget

Re: [PATCH] t3070: skip ls-files tests with backslash patterns on Windows

[Junio C Hamano]

"Kristofer Karlsson via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Kristofer Karlsson <krka@spotify.com>
>
> On Windows (MINGW), backslashes in pathspecs are silently converted to
> forward slashes (directory separators), which changes the glob semantics.
> This causes 36 test failures in t3070-wildmatch when the "via ls-files"
> variants test patterns containing backslash escapes (e.g. '\[ab]',
> '[\-_]', '[A-\\]').
>
> The wildmatch function itself handles these patterns correctly — only the
> ls-files code path fails because pathspec parsing converts the
> backslashes before they reach the glob matcher.
>
> Skip these ls-files tests on platforms where BSLASHPSPEC is not set,
> which is the existing prereq that captures exactly this semantic:
> "backslashes in pathspec are not directory separators."
>
> Signed-off-by: Kristofer Karlsson <krka@spotify.com>
> ---

Thanks for noticing and addressing this.  I think we fairly recently
started seeing this in GitHub actions CI, which puzzles me since
neither t3070 or wildmatch.[ch] have changed for quite some time.
8a6d158a (doc: document backslash in gitignore patterns, 2025-10-29)
added a few lines to the test about matching with backslash to t3070.

Two questions.

 * Has this been broken on Windows since October, or has something
   external change on Windows recently?  I do not know.  Anybody
   knows?

 * Is this change a workaround that sweeps ugly breakage under the
   rug, or is backslash inherently unusable as an excape character
   when handling paths on Windows (which I am afraid would make
   wildmatch fairly useless there)?

Will queue.  Thanks.