dir.c: don't exclude whole dir prematurely if neg pattern may match

If there is a pattern "!foo/bar", this patch makes it not exclude "foo"
right away. This gives us a chance to examine "foo" and re-include
"foo/bar".

In order for it to detect that the directory under examination should
not be excluded right away, in other words it is a parent directory of a
negative pattern, the "directory path" of the negative pattern must be
literal. Patterns like "!f?o/bar" can't stop "foo" from being excluded.

Basename matching (i.e. "no slashes in the pattern") or must-be-dir
matching (i.e. "trailing slash in the pattern") does not work well with
this. For example, if we descend in "foo" and are examining "foo/abc",
current code for "foo/" pattern will check if path "foo/abc", not "foo",
is a directory. The same problem with basename matching. These may need
big code reorg to make it work.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/t/t3001-ls-files-others-exclude.sh b/t/t3001-ls-files-others-exclude.sh
index b2798fe..2a13af1 100755
--- a/t/t3001-ls-files-others-exclude.sh
+++ b/t/t3001-ls-files-others-exclude.sh
@@ -305,4 +305,29 @@ test_expect_success 'ls-files with "**" patterns and no slashes' '
 	test_cmp expect actual
 '
 
+test_expect_success 'negative patterns' '
+	git init reinclude &&
+	(
+		cd reinclude &&
+		cat >.gitignore <<-\EOF &&
+		/fooo
+		/foo
+		!foo/bar/bar
+		EOF
+		mkdir fooo &&
+		cat >fooo/.gitignore <<-\EOF &&
+		!/*
+		EOF
+		mkdir -p foo/bar &&
+		touch abc foo/def foo/bar/ghi foo/bar/bar &&
+		git ls-files -o --exclude-standard >../actual &&
+		cat >../expected <<-\EOF &&
+		.gitignore
+		abc
+		foo/bar/bar
+		EOF
+		test_cmp ../expected ../actual
+	)
+'
+
 test_done