t3011: demonstrate directory traversal failures

Add several tests demonstrating directory traversal failures of various
sorts in dir.c (and one similar looking test that turns out to be a
git_fnmatch bug).  A lot of these tests look like near duplicates of
each other, but an optimization path in dir.c to pre-descend into a
common prefix and the specialized treatment of trailing slashes in dir.c
mean the tiny differences are sometimes important and potentially cause
different codepaths to be explored.

Of the 7 failing tests, 2 are new to git-2.24.0 (tweaked by side effects
of the en/clean-nested-with-ignored-topic); the other 5 also failed
under git-2.23.0 and earlier.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t3011-common-prefixes-and-directory-traversal.sh b/t/t3011-common-prefixes-and-directory-traversal.sh
new file mode 100755 (executable)
index 0000000..54f80c6
--- /dev/null
+++ b/t/t3011-common-prefixes-and-directory-traversal.sh
@@ -0,0 +1,209 @@
+#!/bin/sh
+
+test_description='directory traversal handling, especially with common prefixes'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+       test_commit hello &&
+
+       >empty &&
+       mkdir untracked_dir &&
+       >untracked_dir/empty &&
+       git init untracked_repo &&
+       >untracked_repo/empty &&
+
+       cat <<-EOF >.gitignore &&
+       ignored
+       an_ignored_dir/
+       EOF
+       mkdir an_ignored_dir &&
+       mkdir an_untracked_dir &&
+       >an_ignored_dir/ignored &&
+       >an_ignored_dir/untracked &&
+       >an_untracked_dir/ignored &&
+       >an_untracked_dir/untracked
+'
+
+test_expect_success 'git ls-files -o shows the right entries' '
+       cat <<-EOF >expect &&
+       .gitignore
+       actual
+       an_ignored_dir/ignored
+       an_ignored_dir/untracked
+       an_untracked_dir/ignored
+       an_untracked_dir/untracked
+       empty
+       expect
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o --exclude-standard shows the right entries' '
+       cat <<-EOF >expect &&
+       .gitignore
+       actual
+       an_untracked_dir/untracked
+       empty
+       expect
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o --exclude-standard >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o untracked_dir recurses' '
+       echo untracked_dir/empty >expect &&
+       git ls-files -o untracked_dir >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o untracked_dir/ recurses' '
+       echo untracked_dir/empty >expect &&
+       git ls-files -o untracked_dir/ >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o --directory untracked_dir does not recurse' '
+       echo untracked_dir/ >expect &&
+       git ls-files -o --directory untracked_dir >actual &&
+       test_cmp expect actual
+'
+
+test_expect_failure 'git ls-files -o --directory untracked_dir/ does not recurse' '
+       echo untracked_dir/ >expect &&
+       git ls-files -o --directory untracked_dir/ >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o untracked_repo does not recurse' '
+       echo untracked_repo/ >expect &&
+       git ls-files -o untracked_repo >actual &&
+       test_cmp expect actual
+'
+
+test_expect_failure 'git ls-files -o untracked_repo/ does not recurse' '
+       echo untracked_repo/ >expect &&
+       git ls-files -o untracked_repo/ >actual &&
+       test_cmp expect actual
+'
+
+test_expect_failure 'git ls-files -o untracked_dir untracked_repo recurses into untracked_dir only' '
+       cat <<-EOF >expect &&
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o untracked_dir untracked_repo >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o untracked_dir/ untracked_repo/ recurses into untracked_dir only' '
+       cat <<-EOF >expect &&
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o untracked_dir/ untracked_repo/ >actual &&
+       test_cmp expect actual
+'
+
+test_expect_failure 'git ls-files -o --directory untracked_dir untracked_repo does not recurse' '
+       cat <<-EOF >expect &&
+       untracked_dir/
+       untracked_repo/
+       EOF
+       git ls-files -o --directory untracked_dir untracked_repo >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o --directory untracked_dir/ untracked_repo/ does not recurse' '
+       cat <<-EOF >expect &&
+       untracked_dir/
+       untracked_repo/
+       EOF
+       git ls-files -o --directory untracked_dir/ untracked_repo/ >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o .git shows nothing' '
+       git ls-files -o .git >actual &&
+       test_must_be_empty actual
+'
+
+test_expect_failure 'git ls-files -o .git/ shows nothing' '
+       git ls-files -o .git/ >actual &&
+       test_must_be_empty actual
+'
+
+test_expect_success FUNNYNAMES 'git ls-files -o untracked_* recurses appropriately' '
+       mkdir "untracked_*" &&
+       >"untracked_*/empty" &&
+
+       cat <<-EOF >expect &&
+       untracked_*/empty
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o "untracked_*" >actual &&
+       test_cmp expect actual
+'
+
+# It turns out fill_directory returns the right paths, but ls-files' post-call
+# filtering in show_dir_entry() via calling dir_path_match() which ends up
+# in git_fnmatch() has logic for PATHSPEC_ONESTAR that assumes the pathspec
+# must match the full path; it doesn't check it for matching a leading
+# directory.
+test_expect_failure FUNNYNAMES 'git ls-files -o untracked_*/ recurses appropriately' '
+       cat <<-EOF >expect &&
+       untracked_*/empty
+       untracked_dir/empty
+       untracked_repo/
+       EOF
+       git ls-files -o "untracked_*/" >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success FUNNYNAMES 'git ls-files -o --directory untracked_* does not recurse' '
+       cat <<-EOF >expect &&
+       untracked_*/
+       untracked_dir/
+       untracked_repo/
+       EOF
+       git ls-files -o --directory "untracked_*" >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success FUNNYNAMES 'git ls-files -o --directory untracked_*/ does not recurse' '
+       cat <<-EOF >expect &&
+       untracked_*/
+       untracked_dir/
+       untracked_repo/
+       EOF
+       git ls-files -o --directory "untracked_*/" >actual &&
+       test_cmp expect actual
+'
+
+test_expect_success 'git ls-files -o consistent between one or two dirs' '
+       git ls-files -o --exclude-standard an_ignored_dir/ an_untracked_dir/ >tmp &&
+       ! grep ^an_ignored_dir/ tmp >expect &&
+       git ls-files -o --exclude-standard an_ignored_dir/ >actual &&
+       test_cmp expect actual
+'
+
+# ls-files doesn't have a way to request showing both untracked and ignored
+# files at the same time, so use `git status --ignored`
+test_expect_failure 'git status --ignored shows same files under dir with or without pathspec' '
+       cat <<-EOF >expect &&
+       ?? an_untracked_dir/
+       !! an_untracked_dir/ignored
+       EOF
+       git status --porcelain --ignored >output &&
+       grep an_untracked_dir output >expect &&
+       git status --porcelain --ignored an_untracked_dir/ >actual &&
+       test_cmp expect actual
+'
+
+test_done