Merge branch 'jk/faster-name-conflicts'

Optimize the check to see if a ref $F can be created by making sure
no existing ref has $F/ as its prefix, which especially matters in
a repository with a large number of existing refs.

* jk/faster-name-conflicts:
  refs: speed up is_refname_available

1 files changed, 30 insertions, 1 deletions

diff --git a/t/t3210-pack-refs.sh b/t/t3210-pack-refs.sh
index 3a017bf437..aa9eb3a3e5 100755
--- a/t/t3210-pack-refs.sh
+++ b/t/t3210-pack-refs.sh
@@ -11,7 +11,9 @@ semantic is still the same.
 '
 . ./test-lib.sh
 
-echo '[core] logallrefupdates = true' >>.git/config
+test_expect_success 'enable reflogs' '
+	git config core.logallrefupdates true
+'
 
 test_expect_success \
     'prepare a trivial repository' \
@@ -158,4 +160,31 @@ test_expect_success 'pack ref directly below refs/' '
 	test_path_is_missing .git/refs/top
 '
 
+test_expect_success 'disable reflogs' '
+	git config core.logallrefupdates false &&
+	rm -rf .git/logs
+'
+
+test_expect_success 'create packed foo/bar/baz branch' '
+	git branch foo/bar/baz &&
+	git pack-refs --all --prune &&
+	test_path_is_missing .git/refs/heads/foo/bar/baz &&
+	test_path_is_missing .git/logs/refs/heads/foo/bar/baz
+'
+
+test_expect_success 'notice d/f conflict with existing directory' '
+	test_must_fail git branch foo &&
+	test_must_fail git branch foo/bar
+'
+
+test_expect_success 'existing directory reports concrete ref' '
+	test_must_fail git branch foo 2>stderr &&
+	grep refs/heads/foo/bar/baz stderr
+'
+
+test_expect_success 'notice d/f conflict with existing ref' '
+	test_must_fail git branch foo/bar/baz/extra &&
+	test_must_fail git branch foo/bar/baz/lots/of/extra/components
+'
+
 test_done