Write index file on any checkout of files

We need to rewrite the index file when we check out files, even if we
haven't modified the blob info by reading from another tree, so that
we get the stat cache to include the fact that we just modified the
file so it doesn't need to be refreshed.

While we're at it, move everything that needs to be done to check out
some paths from a tree (or the current index) into checkout_paths().

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/t/t2009-checkout-statinfo.sh b/t/t2009-checkout-statinfo.sh
new file mode 100755
index 0000000..f3c2152
--- /dev/null
+++ b/t/t2009-checkout-statinfo.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='checkout should leave clean stat info'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+
+	echo hello >world &&
+	git update-index --add world &&
+	git commit -m initial &&
+	git branch side &&
+	echo goodbye >world &&
+	git update-index --add world &&
+	git commit -m second
+
+'
+
+test_expect_success 'branch switching' '
+
+	git reset --hard &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout master &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout side &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout master &&
+	test "$(git diff-files --raw)" = ""
+
+'
+
+test_expect_success 'path checkout' '
+
+	git reset --hard &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout master world &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout side world &&
+	test "$(git diff-files --raw)" = "" &&
+
+	git checkout master world &&
+	test "$(git diff-files --raw)" = ""
+
+'
+
+test_done
+