Sync with 2.31.7

* maint-2.31:
  Git 2.31.7
  Git 2.30.8
  apply: fix writing behind newly created symbolic links
  dir-iterator: prevent top-level symlinks without FOLLOW_SYMLINKS
  clone: delay picking a transport until after get_repo_path()
  t5619: demonstrate clone_local() with ambiguous transport

t/t0066-dir-iterator.sh

@@ -109,7 +109,9 @@ test_expect_success SYMLINKS 'setup dirs with symlinks' '
 	mkdir -p dir5/a/c &&
 	ln -s ../c dir5/a/b/d &&
 	ln -s ../ dir5/a/b/e &&
-	ln -s ../../ dir5/a/b/f
+	ln -s ../../ dir5/a/b/f &&
+
+	ln -s dir4 dir6
 '
 
 test_expect_success SYMLINKS 'dir-iterator should not follow symlinks by default' '
@@ -145,4 +147,27 @@ test_expect_success SYMLINKS 'dir-iterator should follow symlinks w/ follow flag
 	test_cmp expected-follow-sorted-output actual-follow-sorted-output
 '
 
+test_expect_success SYMLINKS 'dir-iterator does not resolve top-level symlinks' '
+	test_must_fail test-tool dir-iterator ./dir6 >out &&
+
+	grep "ENOTDIR" out
+'
+
+test_expect_success SYMLINKS 'dir-iterator resolves top-level symlinks w/ follow flag' '
+	cat >expected-follow-sorted-output <<-EOF &&
+	[d] (a) [a] ./dir6/a
+	[d] (a/f) [f] ./dir6/a/f
+	[d] (a/f/c) [c] ./dir6/a/f/c
+	[d] (b) [b] ./dir6/b
+	[d] (b/c) [c] ./dir6/b/c
+	[f] (a/d) [d] ./dir6/a/d
+	[f] (a/e) [e] ./dir6/a/e
+	EOF
+
+	test-tool dir-iterator --follow-symlinks ./dir6 >out &&
+	sort out >actual-follow-sorted-output &&
+
+	test_cmp expected-follow-sorted-output actual-follow-sorted-output
+'
+
 test_done

t/t4115-apply-symlink.sh

@@ -44,4 +44,85 @@ test_expect_success 'apply --index symlink patch' '
 
 '
 
+test_expect_success 'symlink setup' '
+	ln -s .git symlink &&
+	git add symlink &&
+	git commit -m "add symlink"
+'
+
+test_expect_success SYMLINKS 'symlink escape when creating new files' '
+	test_when_finished "git reset --hard && git clean -dfx" &&
+
+	cat >patch <<-EOF &&
+	diff --git a/symlink b/renamed-symlink
+	similarity index 100%
+	rename from symlink
+	rename to renamed-symlink
+	--
+	diff --git /dev/null b/renamed-symlink/create-me
+	new file mode 100644
+	index 0000000..039727e
+	--- /dev/null
+	+++ b/renamed-symlink/create-me
+	@@ -0,0 +1,1 @@
+	+busted
+	EOF
+
+	test_must_fail git apply patch 2>stderr &&
+	cat >expected_stderr <<-EOF &&
+	error: affected file ${SQ}renamed-symlink/create-me${SQ} is beyond a symbolic link
+	EOF
+	test_cmp expected_stderr stderr &&
+	! test_path_exists .git/create-me
+'
+
+test_expect_success SYMLINKS 'symlink escape when modifying file' '
+	test_when_finished "git reset --hard && git clean -dfx" &&
+	touch .git/modify-me &&
+
+	cat >patch <<-EOF &&
+	diff --git a/symlink b/renamed-symlink
+	similarity index 100%
+	rename from symlink
+	rename to renamed-symlink
+	--
+	diff --git a/renamed-symlink/modify-me b/renamed-symlink/modify-me
+	index 1111111..2222222 100644
+	--- a/renamed-symlink/modify-me
+	+++ b/renamed-symlink/modify-me
+	@@ -0,0 +1,1 @@
+	+busted
+	EOF
+
+	test_must_fail git apply patch 2>stderr &&
+	cat >expected_stderr <<-EOF &&
+	error: renamed-symlink/modify-me: No such file or directory
+	EOF
+	test_cmp expected_stderr stderr &&
+	test_must_be_empty .git/modify-me
+'
+
+test_expect_success SYMLINKS 'symlink escape when deleting file' '
+	test_when_finished "git reset --hard && git clean -dfx && rm .git/delete-me" &&
+	touch .git/delete-me &&
+
+	cat >patch <<-EOF &&
+	diff --git a/symlink b/renamed-symlink
+	similarity index 100%
+	rename from symlink
+	rename to renamed-symlink
+	--
+	diff --git a/renamed-symlink/delete-me b/renamed-symlink/delete-me
+	deleted file mode 100644
+	index 1111111..0000000 100644
+	EOF
+
+	test_must_fail git apply patch 2>stderr &&
+	cat >expected_stderr <<-EOF &&
+	error: renamed-symlink/delete-me: No such file or directory
+	EOF
+	test_cmp expected_stderr stderr &&
+	test_path_is_file .git/delete-me
+'
+
 test_done

t/t5604-clone-reference.sh

@@ -344,4 +344,20 @@ test_expect_success SYMLINKS 'clone repo with symlinked or unknown files at obje
 	test_must_be_empty T--shared.objects-symlinks.raw
 '
 
+test_expect_success SYMLINKS 'clone repo with symlinked objects directory' '
+	test_when_finished "rm -fr sensitive malicious" &&
+
+	mkdir -p sensitive &&
+	echo "secret" >sensitive/file &&
+
+	git init malicious &&
+	rm -fr malicious/.git/objects &&
+	ln -s "$(pwd)/sensitive" ./malicious/.git/objects &&
+
+	test_must_fail git clone --local malicious clone 2>err &&
+
+	test_path_is_missing clone &&
+	grep "failed to start iterator over" err
+'
+
 test_done

t/t5619-clone-local-ambiguous-transport.sh

@@ -0,0 +1,70 @@
+#!/bin/sh
+
+test_description='test local clone with ambiguous transport'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-httpd.sh"
+
+if ! test_have_prereq SYMLINKS
+then
+	skip_all='skipping test, symlink support unavailable'
+	test_done
+fi
+
+start_httpd
+
+REPO="$HTTPD_DOCUMENT_ROOT_PATH/sub.git"
+URI="$HTTPD_URL/dumb/sub.git"
+
+test_expect_success 'setup' '
+	mkdir -p sensitive &&
+	echo "secret" >sensitive/secret &&
+
+	git init --bare "$REPO" &&
+	test_commit_bulk -C "$REPO" --ref=main 1 &&
+
+	git -C "$REPO" update-ref HEAD main &&
+	git -C "$REPO" update-server-info &&
+
+	git init malicious &&
+	(
+		cd malicious &&
+
+		git submodule add "$URI" &&
+
+		mkdir -p repo/refs &&
+		touch repo/refs/.gitkeep &&
+		printf "ref: refs/heads/a" >repo/HEAD &&
+		ln -s "$(cd .. && pwd)/sensitive" repo/objects &&
+
+		mkdir -p "$HTTPD_URL/dumb" &&
+		ln -s "../../../.git/modules/sub/../../../repo/" "$URI" &&
+
+		git add . &&
+		git commit -m "initial commit"
+	) &&
+
+	# Delete all of the references in our malicious submodule to
+	# avoid the client attempting to checkout any objects (which
+	# will be missing, and thus will cause the clone to fail before
+	# we can trigger the exploit).
+	git -C "$REPO" for-each-ref --format="delete %(refname)" >in &&
+	git -C "$REPO" update-ref --stdin <in &&
+	git -C "$REPO" update-server-info
+'
+
+test_expect_success 'ambiguous transport does not lead to arbitrary file-inclusion' '
+	git clone malicious clone &&
+	test_must_fail git -C clone submodule update --init 2>err &&
+
+	test_path_is_missing clone/.git/modules/sub/objects/secret &&
+	# We would actually expect "transport .file. not allowed" here,
+	# but due to quirks of the URL detection in Git, we mis-parse
+	# the absolute path as a bogus URL and die before that step.
+	#
+	# This works for now, and if we ever fix the URL detection, it
+	# is OK to change this to detect the transport error.
+	grep "protocol .* is not supported" err
+'
+
+test_done