Merge branch 'js/checkout-detach-count' into maint

When checking out another commit from an already detached state, we used
to report all commits that are not reachable from any of the refs as
lossage, but some of them might be reachable from the new HEAD, and there
is no need to warn about them.

By Johannes Sixt
* js/checkout-detach-count:
  checkout (detached): truncate list of orphaned commits at the new HEAD
  t2020-checkout-detach: check for the number of orphaned commits

1 files changed, 16 insertions, 5 deletions

diff --git a/t/t2020-checkout-detach.sh b/t/t2020-checkout-detach.sh
index 068fba4c8e..f63333b64e 100755
--- a/t/t2020-checkout-detach.sh
+++ b/t/t2020-checkout-detach.sh
@@ -11,14 +11,13 @@ check_not_detached () {
 	git symbolic-ref -q HEAD >/dev/null
 }
 
-ORPHAN_WARNING='you are leaving .* commit.*behind'
 PREV_HEAD_DESC='Previous HEAD position was'
 check_orphan_warning() {
-	test_i18ngrep "$ORPHAN_WARNING" "$1" &&
+	test_i18ngrep "you are leaving $2 behind" "$1" &&
 	test_i18ngrep ! "$PREV_HEAD_DESC" "$1"
 }
 check_no_orphan_warning() {
-	test_i18ngrep ! "$ORPHAN_WARNING" "$1" &&
+	test_i18ngrep ! "you are leaving .* commit.*behind" "$1" &&
 	test_i18ngrep "$PREV_HEAD_DESC" "$1"
 }
 
@@ -110,12 +109,24 @@ test_expect_success 'checkout warns on orphan commits' '
 	git checkout --detach two &&
 	echo content >orphan &&
 	git add orphan &&
-	git commit -a -m orphan &&
+	git commit -a -m orphan1 &&
+	echo new content >orphan &&
+	git commit -a -m orphan2 &&
+	orphan2=$(git rev-parse HEAD) &&
 	git checkout master 2>stderr
 '
 
 test_expect_success 'checkout warns on orphan commits: output' '
-	check_orphan_warning stderr
+	check_orphan_warning stderr "2 commits"
+'
+
+test_expect_success 'checkout warns orphaning 1 of 2 commits' '
+	git checkout "$orphan2" &&
+	git checkout HEAD^ 2>stderr
+'
+
+test_expect_success 'checkout warns orphaning 1 of 2 commits: output' '
+	check_orphan_warning stderr "1 commit"
 '
 
 test_expect_success 'checkout does not warn leaving ref tip' '