clean: show an error message when the path is too long

When `lstat()` failed, `git clean` would abort without an error
message, leaving the user quite puzzled.

In particular on Windows, where the default maximum path length is
quite small (yet there are ways to circumvent that limit in many
cases), it is very important that users be given an indication why
their command failed because of too long paths when it did.

This test case makes sure that a warning is issued that would have
helped the user who reported this issue:

	https://github.com/git-for-windows/git/issues/521

Note that we temporarily set `core.longpaths = false` in the regression
test; this ensures forward-compatibility with the `core.longpaths`
feature that has not yet been upstreamed from Git for Windows.

Helped-by: René Scharfe <l.s.r@web.de>
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/builtin/clean.c b/builtin/clean.c
index aaba4af3c2..d5579da716 100644
--- a/builtin/clean.c
+++ b/builtin/clean.c
@@ -34,6 +34,7 @@ static const char *msg_would_remove = N_("Would remove %s\n");
 static const char *msg_skip_git_dir = N_("Skipping repository %s\n");
 static const char *msg_would_skip_git_dir = N_("Would skip repository %s\n");
 static const char *msg_warn_remove_failed = N_("failed to remove %s");
+static const char *msg_warn_lstat_failed = N_("could not lstat %s\n");
 
 enum color_clean {
 	CLEAN_COLOR_RESET = 0,
@@ -194,7 +195,7 @@ static int remove_dirs(struct strbuf *path, const char *prefix, int force_flag,
 		strbuf_setlen(path, len);
 		strbuf_addstr(path, e->d_name);
 		if (lstat(path->buf, &st))
-			; /* fall thru */
+			warning_errno(_(msg_warn_lstat_failed), path->buf);
 		else if (S_ISDIR(st.st_mode)) {
 			if (remove_dirs(path, prefix, force_flag, dry_run, quiet, &gone))
 				ret = 1;