exclude: do not respect symlinks for in-tree .gitignorejk/nofollow-attr-ignore

Like .gitattributes, we would like to make sure that
.gitignore files are handled consistently whether read from
the index or from the filesystem. We can do so by using
O_NOFOLLOW when opening the files.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 36 insertions, 2 deletions

diff --git a/dir.c b/dir.c
index 4fa1ca1097..cf3fde0056 100644
--- a/dir.c
+++ b/dir.c
@@ -693,6 +693,7 @@ static void invalidate_directory(struct untracked_cache *uc,
 
 /* Flags for add_excludes() */
 #define EXCLUDE_CHECK_INDEX (1<<0)
+#define EXCLUDE_NOFOLLOW (1<<1)
 
 /*
  * Given a file with name "fname", read it (either from disk, or from
@@ -713,7 +714,11 @@ static int add_excludes(const char *fname, const char *base, int baselen,
 	size_t size = 0;
 	char *buf, *entry;
 
-	fd = open(fname, O_RDONLY);
+	if (flags & EXCLUDE_NOFOLLOW)
+		fd = open_nofollow(fname, O_RDONLY);
+	else
+		fd = open(fname, O_RDONLY);
+
 	if (fd < 0 || fstat(fd, &st) < 0) {
 		if (errno != ENOENT)
 			warn_on_inaccessible(fname);
@@ -1130,7 +1135,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
 			strbuf_addstr(&sb, dir->exclude_per_dir);
 			el->src = strbuf_detach(&sb, NULL);
 			add_excludes(el->src, el->src, stk->baselen, el,
-				     EXCLUDE_CHECK_INDEX,
+				     EXCLUDE_CHECK_INDEX | EXCLUDE_NOFOLLOW,
 				     untracked ? &sha1_stat : NULL);
 		}
 		/*
diff --git a/t/t0008-ignores.sh b/t/t0008-ignores.sh
index d27f438bf4..7348b8e6a9 100755
--- a/t/t0008-ignores.sh
+++ b/t/t0008-ignores.sh
@@ -841,4 +841,33 @@ test_expect_success 'info/exclude trumps core.excludesfile' '
 	test_cmp expect actual
 '
 
+test_expect_success SYMLINKS 'set up ignore file for symlink tests' '
+	echo "*" >ignore
+'
+
+test_expect_success SYMLINKS 'symlinks respected in core.excludesFile' '
+	test_when_finished "rm symlink" &&
+	ln -s ignore symlink &&
+	test_config core.excludesFile "$(pwd)/symlink" &&
+	echo file >expect &&
+	git check-ignore file >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success SYMLINKS 'symlinks respected in info/exclude' '
+	test_when_finished "rm .git/info/exclude" &&
+	ln -sf ../../ignore .git/info/exclude &&
+	echo file >expect &&
+	git check-ignore file >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success SYMLINKS 'symlinks not respected in-tree' '
+	test_when_finished "rm .gitignore" &&
+	ln -sf ignore .gitignore &&
+	>expect &&
+	test_must_fail git check-ignore file >actual &&
+	test_cmp expect actual
+'
+
 test_done