Merge branch 'ds/branch-checked-out' into ds/rebase-update-ref

* ds/branch-checked-out:
  branch: drop unused worktrees variable
  fetch: stop passing around unused worktrees variable
  branch: fix branch_checked_out() leaks
  branch: use branch_checked_out() when deleting refs
  fetch: use new branch_checked_out() and add tests
  branch: check for bisects and rebases
  branch: add branch_checked_out() helper

branch.c

@@ -10,6 +10,7 @@
 #include "worktree.h"
 #include "submodule-config.h"
 #include "run-command.h"
+#include "strmap.h"
 
 struct tracking {
 	struct refspec_item spec;
@@ -369,6 +370,70 @@ int validate_branchname(const char *name, struct strbuf *ref)
 	return ref_exists(ref->buf);
 }
 
+static int initialized_checked_out_branches;
+static struct strmap current_checked_out_branches = STRMAP_INIT;
+
+static void prepare_checked_out_branches(void)
+{
+	int i = 0;
+	struct worktree **worktrees;
+
+	if (initialized_checked_out_branches)
+		return;
+	initialized_checked_out_branches = 1;
+
+	worktrees = get_worktrees();
+
+	while (worktrees[i]) {
+		char *old;
+		struct wt_status_state state = { 0 };
+		struct worktree *wt = worktrees[i++];
+
+		if (wt->is_bare)
+			continue;
+
+		if (wt->head_ref) {
+			old = strmap_put(&current_checked_out_branches,
+					 wt->head_ref,
+					 xstrdup(wt->path));
+			free(old);
+		}
+
+		if (wt_status_check_rebase(wt, &state) &&
+		    (state.rebase_in_progress || state.rebase_interactive_in_progress) &&
+		    state.branch) {
+			struct strbuf ref = STRBUF_INIT;
+			strbuf_addf(&ref, "refs/heads/%s", state.branch);
+			old = strmap_put(&current_checked_out_branches,
+					 ref.buf,
+					 xstrdup(wt->path));
+			free(old);
+			strbuf_release(&ref);
+		}
+		wt_status_state_free_buffers(&state);
+
+		if (wt_status_check_bisect(wt, &state) &&
+		    state.branch) {
+			struct strbuf ref = STRBUF_INIT;
+			strbuf_addf(&ref, "refs/heads/%s", state.branch);
+			old = strmap_put(&current_checked_out_branches,
+					 ref.buf,
+					 xstrdup(wt->path));
+			free(old);
+			strbuf_release(&ref);
+		}
+		wt_status_state_free_buffers(&state);
+	}
+
+	free_worktrees(worktrees);
+}
+
+const char *branch_checked_out(const char *refname)
+{
+	prepare_checked_out_branches();
+	return strmap_get(&current_checked_out_branches, refname);
+}
+
 /*
  * Check if a branch 'name' can be created as a new branch; die otherwise.
  * 'force' can be used when it is OK for the named branch already exists.
@@ -377,9 +442,7 @@ int validate_branchname(const char *name, struct strbuf *ref)
  */
 int validate_new_branchname(const char *name, struct strbuf *ref, int force)
 {
-	struct worktree **worktrees;
+	const char *path;
-	const struct worktree *wt;
-
 	if (!validate_branchname(name, ref))
 		return 0;
 
@@ -387,13 +450,10 @@ int validate_new_branchname(const char *name, struct strbuf *ref, int force)
 		die(_("a branch named '%s' already exists"),
 		    ref->buf + strlen("refs/heads/"));
 
-	worktrees = get_worktrees();
+	if ((path = branch_checked_out(ref->buf)))
-	wt = find_shared_symref(worktrees, "HEAD", ref->buf);
-	if (wt && !wt->is_bare)
 		die(_("cannot force update the branch '%s' "
 		      "checked out at '%s'"),
-		    ref->buf + strlen("refs/heads/"), wt->path);
+		    ref->buf + strlen("refs/heads/"), path);
-	free_worktrees(worktrees);
 
 	return 1;
 }

branch.h

@@ -101,6 +101,13 @@ void create_branches_recursively(struct repository *r, const char *name,
 				 const char *tracking_name, int force,
 				 int reflog, int quiet, enum branch_track track,
 				 int dry_run);
+
+/*
+ * If the branch at 'refname' is currently checked out in a worktree,
+ * then return the path to that worktree.
+ */
+const char *branch_checked_out(const char *refname);
+
 /*
  * Check if 'name' can be a valid name for a branch; die otherwise.
  * Return 1 if the named branch already exists; return 0 otherwise.

builtin/branch.c

@@ -204,7 +204,6 @@ static void delete_branch_config(const char *branchname)
 static int delete_branches(int argc, const char **argv, int force, int kinds,
 			   int quiet)
 {
-	struct worktree **worktrees;
 	struct commit *head_rev = NULL;
 	struct object_id oid;
 	char *name = NULL;
@@ -242,8 +241,6 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 			die(_("Couldn't look up commit object for HEAD"));
 	}
 
-	worktrees = get_worktrees();
-
 	for (i = 0; i < argc; i++, strbuf_reset(&bname)) {
 		char *target = NULL;
 		int flags = 0;
@@ -253,12 +250,11 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 		name = mkpathdup(fmt, bname.buf);
 
 		if (kinds == FILTER_REFS_BRANCHES) {
-			const struct worktree *wt =
+			const char *path;
-				find_shared_symref(worktrees, "HEAD", name);
+			if ((path = branch_checked_out(name))) {
-			if (wt) {
 				error(_("Cannot delete branch '%s' "
 					"checked out at '%s'"),
-				      bname.buf, wt->path);
+				      bname.buf, path);
 				ret = 1;
 				continue;
 			}
@@ -315,7 +311,6 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 
 	free(name);
 	strbuf_release(&bname);
-	free_worktrees(worktrees);
 
 	return ret;
 }

builtin/fetch.c

@@ -881,11 +881,9 @@ static void format_display(struct strbuf *display, char code,
 static int update_local_ref(struct ref *ref,
 			    struct ref_transaction *transaction,
 			    const char *remote, const struct ref *remote_ref,
-			    struct strbuf *display, int summary_width,
+			    struct strbuf *display, int summary_width)
-			    struct worktree **worktrees)
 {
 	struct commit *current = NULL, *updated;
-	const struct worktree *wt;
 	const char *pretty_ref = prettify_refname(ref->name);
 	int fast_forward = 0;
 
@@ -900,16 +898,14 @@ static int update_local_ref(struct ref *ref,
 	}
 
 	if (!update_head_ok &&
-	    (wt = find_shared_symref(worktrees, "HEAD", ref->name)) &&
+	    !is_null_oid(&ref->old_oid) &&
-	    !wt->is_bare && !is_null_oid(&ref->old_oid)) {
+	    branch_checked_out(ref->name)) {
 		/*
 		 * If this is the head, and it's not okay to update
 		 * the head, and the old value of the head isn't empty...
 		 */
 		format_display(display, '!', _("[rejected]"),
-			       wt->is_current ?
+			       _("can't fetch into checked-out branch"),
-				       _("can't fetch in current branch") :
-				       _("checked out in another worktree"),
 			       remote, pretty_ref, summary_width);
 		return 1;
 	}
@@ -1110,7 +1106,7 @@ N_("it took %.2f seconds to check forced updates; you can use\n"
 static int store_updated_refs(const char *raw_url, const char *remote_name,
 			      int connectivity_checked,
 			      struct ref_transaction *transaction, struct ref *ref_map,
-			      struct fetch_head *fetch_head, struct worktree **worktrees)
+			      struct fetch_head *fetch_head)
 {
 	int url_len, i, rc = 0;
 	struct strbuf note = STRBUF_INIT, err = STRBUF_INIT;
@@ -1240,8 +1236,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name,
 			strbuf_reset(&note);
 			if (ref) {
 				rc |= update_local_ref(ref, transaction, what,
-						       rm, &note, summary_width,
+						       rm, &note, summary_width);
-						       worktrees);
 				free(ref);
 			} else if (write_fetch_head || dry_run) {
 				/*
@@ -1332,8 +1327,7 @@ static int check_exist_and_connected(struct ref *ref_map)
 static int fetch_and_consume_refs(struct transport *transport,
 				  struct ref_transaction *transaction,
 				  struct ref *ref_map,
-				  struct fetch_head *fetch_head,
+				  struct fetch_head *fetch_head)
-				  struct worktree **worktrees)
 {
 	int connectivity_checked = 1;
 	int ret;
@@ -1356,7 +1350,7 @@ static int fetch_and_consume_refs(struct transport *transport,
 	trace2_region_enter("fetch", "consume_refs", the_repository);
 	ret = store_updated_refs(transport->url, transport->remote->name,
 				 connectivity_checked, transaction, ref_map,
-				 fetch_head, worktrees);
+				 fetch_head);
 	trace2_region_leave("fetch", "consume_refs", the_repository);
 
 out:
@@ -1434,19 +1428,16 @@ cleanup:
 	return result;
 }
 
-static void check_not_current_branch(struct ref *ref_map,
+static void check_not_current_branch(struct ref *ref_map)
-				     struct worktree **worktrees)
 {
-	const struct worktree *wt;
+	const char *path;
 	for (; ref_map; ref_map = ref_map->next)
 		if (ref_map->peer_ref &&
 		    starts_with(ref_map->peer_ref->name, "refs/heads/") &&
-		    (wt = find_shared_symref(worktrees, "HEAD",
+		    (path = branch_checked_out(ref_map->peer_ref->name)))
-					     ref_map->peer_ref->name)) &&
-		    !wt->is_bare)
 			die(_("refusing to fetch into branch '%s' "
 			      "checked out at '%s'"),
-			    ref_map->peer_ref->name, wt->path);
+			    ref_map->peer_ref->name, path);
 }
 
 static int truncate_fetch_head(void)
@@ -1549,8 +1540,7 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 static int backfill_tags(struct transport *transport,
 			 struct ref_transaction *transaction,
 			 struct ref *ref_map,
-			 struct fetch_head *fetch_head,
+			 struct fetch_head *fetch_head)
-			 struct worktree **worktrees)
 {
 	int retcode, cannot_reuse;
 
@@ -1571,7 +1561,7 @@ static int backfill_tags(struct transport *transport,
 	transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
 	transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 	transport_set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, NULL);
-	retcode = fetch_and_consume_refs(transport, transaction, ref_map, fetch_head, worktrees);
+	retcode = fetch_and_consume_refs(transport, transaction, ref_map, fetch_head);
 
 	if (gsecondary) {
 		transport_disconnect(gsecondary);
@@ -1592,7 +1582,6 @@ static int do_fetch(struct transport *transport,
 	struct transport_ls_refs_options transport_ls_refs_options =
 		TRANSPORT_LS_REFS_OPTIONS_INIT;
 	int must_list_refs = 1;
-	struct worktree **worktrees = get_worktrees();
 	struct fetch_head fetch_head = { 0 };
 	struct strbuf err = STRBUF_INIT;
 
@@ -1650,7 +1639,7 @@ static int do_fetch(struct transport *transport,
 	ref_map = get_ref_map(transport->remote, remote_refs, rs,
 			      tags, &autotags);
 	if (!update_head_ok)
-		check_not_current_branch(ref_map, worktrees);
+		check_not_current_branch(ref_map);
 
 	retcode = open_fetch_head(&fetch_head);
 	if (retcode)
@@ -1683,7 +1672,7 @@ static int do_fetch(struct transport *transport,
 			retcode = 1;
 	}
 
-	if (fetch_and_consume_refs(transport, transaction, ref_map, &fetch_head, worktrees)) {
+	if (fetch_and_consume_refs(transport, transaction, ref_map, &fetch_head)) {
 		retcode = 1;
 		goto cleanup;
 	}
@@ -1706,7 +1695,7 @@ static int do_fetch(struct transport *transport,
 			 * the transaction and don't commit anything.
 			 */
 			if (backfill_tags(transport, transaction, tags_ref_map,
-					  &fetch_head, worktrees))
+					  &fetch_head))
 				retcode = 1;
 		}
 
@@ -1791,7 +1780,6 @@ cleanup:
 	close_fetch_head(&fetch_head);
 	strbuf_release(&err);
 	free_refs(ref_map);
-	free_worktrees(worktrees);
 	return retcode;
 }
 

t/t2407-worktree-heads.sh

@@ -0,0 +1,129 @@
+#!/bin/sh
+
+test_description='test operations trying to overwrite refs at worktree HEAD'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	test_commit init &&
+	git branch -f fake-1 &&
+	git branch -f fake-2 &&
+
+	for i in 1 2 3 4
+	do
+		test_commit $i &&
+		git branch wt-$i &&
+		git worktree add wt-$i wt-$i || return 1
+	done &&
+
+	# Create a server that updates each branch by one commit
+	git init server &&
+	test_commit -C server initial &&
+	git remote add server ./server &&
+	for i in 1 2 3 4
+	do
+		git -C server checkout -b wt-$i &&
+		test_commit -C server A-$i || return 1
+	done &&
+	for i in 1 2
+	do
+		git -C server checkout -b fake-$i &&
+		test_commit -C server f-$i || return 1
+	done
+'
+
+test_expect_success 'refuse to overwrite: checked out in worktree' '
+	for i in 1 2 3 4
+	do
+		test_must_fail git branch -f wt-$i HEAD 2>err
+		grep "cannot force update the branch" err &&
+
+		test_must_fail git branch -D wt-$i 2>err
+		grep "Cannot delete branch" err || return 1
+	done
+'
+
+test_expect_success 'refuse to overwrite: worktree in bisect' '
+	test_when_finished rm -rf .git/worktrees/wt-*/BISECT_* &&
+
+	touch .git/worktrees/wt-4/BISECT_LOG &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-4/BISECT_START &&
+
+	test_must_fail git branch -f fake-2 HEAD 2>err &&
+	grep "cannot force update the branch '\''fake-2'\'' checked out at.*wt-4" err
+'
+
+test_expect_success 'refuse to overwrite: worktree in rebase' '
+	test_when_finished rm -rf .git/worktrees/wt-*/rebase-merge &&
+
+	mkdir -p .git/worktrees/wt-3/rebase-merge &&
+	touch .git/worktrees/wt-3/rebase-merge/interactive &&
+	echo refs/heads/fake-1 >.git/worktrees/wt-3/rebase-merge/head-name &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-3/rebase-merge/onto &&
+
+	test_must_fail git branch -f fake-1 HEAD 2>err &&
+	grep "cannot force update the branch '\''fake-1'\'' checked out at.*wt-3" err
+'
+
+test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: checked out' '
+	test_must_fail git fetch server +refs/heads/wt-3:refs/heads/wt-3 2>err &&
+	grep "refusing to fetch into branch '\''refs/heads/wt-3'\''" err &&
+
+	# General fetch into refs/heads/ will fail on first ref,
+	# so use a generic error message check.
+	test_must_fail git fetch server +refs/heads/*:refs/heads/* 2>err &&
+	grep "refusing to fetch into branch" err
+'
+
+test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: worktree in bisect' '
+	test_when_finished rm -rf .git/worktrees/wt-*/BISECT_* &&
+
+	touch .git/worktrees/wt-4/BISECT_LOG &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-4/BISECT_START &&
+
+	test_must_fail git fetch server +refs/heads/fake-2:refs/heads/fake-2 2>err &&
+	grep "refusing to fetch into branch" err
+'
+
+test_expect_success !SANITIZE_LEAK 'refuse to fetch over ref: worktree in rebase' '
+	test_when_finished rm -rf .git/worktrees/wt-*/rebase-merge &&
+
+	mkdir -p .git/worktrees/wt-4/rebase-merge &&
+	touch .git/worktrees/wt-4/rebase-merge/interactive &&
+	echo refs/heads/fake-1 >.git/worktrees/wt-4/rebase-merge/head-name &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-4/rebase-merge/onto &&
+
+	test_must_fail git fetch server +refs/heads/fake-1:refs/heads/fake-1 2>err &&
+	grep "refusing to fetch into branch" err
+'
+
+test_expect_success 'refuse to overwrite when in error states' '
+	test_when_finished rm -rf .git/worktrees/wt-*/rebase-merge &&
+	test_when_finished rm -rf .git/worktrees/wt-*/BISECT_* &&
+
+	# Both branches are currently under rebase.
+	mkdir -p .git/worktrees/wt-3/rebase-merge &&
+	touch .git/worktrees/wt-3/rebase-merge/interactive &&
+	echo refs/heads/fake-1 >.git/worktrees/wt-3/rebase-merge/head-name &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-3/rebase-merge/onto &&
+	mkdir -p .git/worktrees/wt-4/rebase-merge &&
+	touch .git/worktrees/wt-4/rebase-merge/interactive &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-4/rebase-merge/head-name &&
+	echo refs/heads/fake-1 >.git/worktrees/wt-4/rebase-merge/onto &&
+
+	# Both branches are currently under bisect.
+	touch .git/worktrees/wt-4/BISECT_LOG &&
+	echo refs/heads/fake-2 >.git/worktrees/wt-4/BISECT_START &&
+	touch .git/worktrees/wt-1/BISECT_LOG &&
+	echo refs/heads/fake-1 >.git/worktrees/wt-1/BISECT_START &&
+
+	for i in 1 2
+	do
+		test_must_fail git branch -f fake-$i HEAD 2>err &&
+		grep "cannot force update the branch '\''fake-$i'\'' checked out at" err ||
+			return 1
+	done
+'
+
+test_done