Merge branch 'ak/protect-any-current-branch'

"git fetch" without the "--update-head-ok" option ought to protect
a checked out branch from getting updated, to prevent the working
tree that checks it out to go out of sync.  The code was written
before the use of "git worktree" got widespread, and only checked
the branch that was checked out in the current worktree, which has
been updated.
(originally called ak/fetch-not-overwrite-any-current-branch)

* ak/protect-any-current-branch:
  branch: protect branches checked out in all worktrees
  receive-pack: protect current branch for bare repository worktree
  receive-pack: clean dead code from update_worktree()
  fetch: protect branches checked out in all worktrees
  worktree: simplify find_shared_symref() memory ownership model
  branch: lowercase error messages
  receive-pack: lowercase error messages
  fetch: lowercase error messages

4 files changed, 43 insertions, 4 deletions

diff --git a/t/t2018-checkout-branch.sh b/t/t2018-checkout-branch.sh
index 93be1c0eae..3e93506c04 100755
--- a/t/t2018-checkout-branch.sh
+++ b/t/t2018-checkout-branch.sh
@@ -148,7 +148,7 @@ test_expect_success 'checkout -b to an existing branch fails' '
 test_expect_success 'checkout -b to @{-1} fails with the right branch name' '
 	git checkout branch1 &&
 	git checkout branch2 &&
-	echo  >expect "fatal: A branch named '\''branch1'\'' already exists." &&
+	echo  >expect "fatal: a branch named '\''branch1'\'' already exists" &&
 	test_must_fail git checkout -b @{-1} 2>actual &&
 	test_cmp expect actual
 '
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index 8c5c1ccf33..8a619d785e 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -168,6 +168,13 @@ test_expect_success 'git branch -M foo bar should fail when bar is checked out'
 	test_must_fail git branch -M bar foo
 '
 
+test_expect_success 'git branch -M foo bar should fail when bar is checked out in worktree' '
+	git branch -f bar &&
+	test_when_finished "git worktree remove wt && git branch -D wt" &&
+	git worktree add wt &&
+	test_must_fail git branch -M bar wt
+'
+
 test_expect_success 'git branch -M baz bam should succeed when baz is checked out' '
 	git checkout -b baz &&
 	git branch bam &&
@@ -888,7 +895,7 @@ test_expect_success '--set-upstream-to fails on a missing src branch' '
 '
 
 test_expect_success '--set-upstream-to fails on a non-ref' '
-	echo "fatal: Cannot setup tracking information; starting point '"'"'HEAD^{}'"'"' is not a branch." >expect &&
+	echo "fatal: cannot set up tracking information; starting point '"'"'HEAD^{}'"'"' is not a branch" >expect &&
 	test_must_fail git branch --set-upstream-to HEAD^{} 2>err &&
 	test_cmp expect err
 '
@@ -975,7 +982,7 @@ test_expect_success 'disabled option --set-upstream fails' '
 test_expect_success '--set-upstream-to notices an error to set branch as own upstream' '
 	git branch --set-upstream-to refs/heads/my13 my13 2>actual &&
 	cat >expect <<-\EOF &&
-	warning: Not setting branch my13 as its own upstream.
+	warning: not setting branch my13 as its own upstream
 	EOF
 	test_expect_code 1 git config branch.my13.remote &&
 	test_expect_code 1 git config branch.my13.merge &&
diff --git a/t/t5504-fetch-receive-strict.sh b/t/t5504-fetch-receive-strict.sh
index 6e5a9c20e7..b0b795aca9 100755
--- a/t/t5504-fetch-receive-strict.sh
+++ b/t/t5504-fetch-receive-strict.sh
@@ -292,7 +292,7 @@ test_expect_success 'push with receive.fsck.missingEmail=warn' '
 		receive.fsck.missingEmail warn &&
 	git push --porcelain dst bogus >act 2>&1 &&
 	grep "missingEmail" act &&
-	test_i18ngrep "Skipping unknown msg id.*whatever" act &&
+	test_i18ngrep "skipping unknown msg id.*whatever" act &&
 	git --git-dir=dst/.git branch -D bogus &&
 	git --git-dir=dst/.git config --add \
 		receive.fsck.missingEmail ignore &&
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 7831a38dde..837a49642a 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1778,6 +1778,38 @@ test_expect_success 'denyCurrentBranch and worktrees' '
 	test_must_fail git -C cloned push origin HEAD:new-wt &&
 	test_config receive.denyCurrentBranch updateInstead &&
 	git -C cloned push origin HEAD:new-wt &&
+	test_path_exists new-wt/first.t &&
 	test_must_fail git -C cloned push --delete origin new-wt
 '
+
+test_expect_success 'denyCurrentBranch and bare repository worktrees' '
+	test_when_finished "rm -fr bare.git" &&
+	git clone --bare . bare.git &&
+	git -C bare.git worktree add wt &&
+	test_commit grape &&
+	git -C bare.git config receive.denyCurrentBranch refuse &&
+	test_must_fail git push bare.git HEAD:wt &&
+	git -C bare.git config receive.denyCurrentBranch updateInstead &&
+	git push bare.git HEAD:wt &&
+	test_path_exists bare.git/wt/grape.t &&
+	test_must_fail git push --delete bare.git wt
+'
+
+test_expect_success 'refuse fetch to current branch of worktree' '
+	test_when_finished "git worktree remove --force wt && git branch -D wt" &&
+	git worktree add wt &&
+	test_commit apple &&
+	test_must_fail git fetch . HEAD:wt &&
+	git fetch -u . HEAD:wt
+'
+
+test_expect_success 'refuse fetch to current branch of bare repository worktree' '
+	test_when_finished "rm -fr bare.git" &&
+	git clone --bare . bare.git &&
+	git -C bare.git worktree add wt &&
+	test_commit banana &&
+	test_must_fail git -C bare.git fetch .. HEAD:wt &&
+	git -C bare.git fetch -u .. HEAD:wt
+'
+
 test_done