git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH v7 5/8] fetch: protect branches checked out in all worktrees

From
Anders Kaseorg <andersk@mit.edu>
Date
Dec 1, 2021, 22:15 UTC
Message-ID
<20211201221547.1796213-6-andersk@mit.edu>
In-Reply-To
<20211201221547.1796213-1-andersk@mit.edu>

Refuse to fetch into the currently checked out branch of any working tree, not just the current one.

Fixes this previously reported bug:
https://lore.kernel.org/git/cb957174-5e9a-5603-ea9e-ac9b58a2eaad@mathema.de/

As a side effect of using find_shared_symref, we’ll also refuse the fetch when we’re on a detached HEAD because we’re rebasing or bisecting on the branch in question. This seems like a sensible change.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
 builtin/fetch.c       | 75 +++++++++++++++++++++++--------------------
 t/t5516-fetch-push.sh | 18 +++++++++++
 2 files changed, 58 insertions(+), 35 deletions(-)
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 16b98523ce..e45185cf9c 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -28,6 +28,7 @@
 #include "promisor-remote.h"
 #include "commit-graph.h"
 #include "shallow.h"
+#include "worktree.h"
 
 #define FORCED_UPDATES_DELAY_WARNING_IN_MS (10 * 1000)
 
@@ -848,13 +849,12 @@ 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)
+			    const char *remote, const struct ref *remote_ref,
+			    struct strbuf *display, int summary_width,
+			    struct worktree **worktrees)
 {
 	struct commit *current = NULL, *updated;
-	struct branch *current_branch = branch_get(NULL);
+	const struct worktree *wt;
 	const char *pretty_ref = prettify_refname(ref->name);
 	int fast_forward = 0;
 
@@ -868,16 +868,17 @@ static int update_local_ref(struct ref *ref,
 		return 0;
 	}
 
-	if (current_branch &&
-	    !strcmp(ref->name, current_branch->name) &&
-	    !(update_head_ok || is_bare_repository()) &&
-	    !is_null_oid(&ref->old_oid)) {
+	if (!update_head_ok &&
+	    (wt = find_shared_symref(worktrees, "HEAD", ref->name)) &&
+	    !wt->is_bare && !is_null_oid(&ref->old_oid)) {
 		/*
 		 * 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]"),
-			       _("can't fetch in current branch"),
+			       wt->is_current ?
+				       _("can't fetch in current branch") :
+				       _("checked out in another worktree"),
 			       remote, pretty_ref, summary_width);
 		return 1;
 	}
@@ -1076,7 +1077,8 @@ N_("it took %.2f seconds to check forced updates; you can use\n"
    "to avoid this check\n");
 
 static int store_updated_refs(const char *raw_url, const char *remote_name,
-			      int connectivity_checked, struct ref *ref_map)
+			      int connectivity_checked, struct ref *ref_map,
+			      struct worktree **worktrees)
 {
 	struct fetch_head fetch_head;
 	int url_len, i, rc = 0;
@@ -1205,7 +1207,8 @@ 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) {
 				/*
@@ -1298,7 +1301,9 @@ static int check_exist_and_connected(struct ref *ref_map)
 	return check_connected(iterate_ref_map, &rm, &opt);
 }
 
-static int fetch_and_consume_refs(struct transport *transport, struct ref *ref_map)
+static int fetch_and_consume_refs(struct transport *transport,
+				  struct ref *ref_map,
+				  struct worktree **worktrees)
 {
 	int connectivity_checked = 1;
 	int ret;
@@ -1319,10 +1324,8 @@ static int fetch_and_consume_refs(struct transport *transport, struct ref *ref_m
 	}
 
 	trace2_region_enter("fetch", "consume_refs", the_repository);
-	ret = store_updated_refs(transport->url,
-				 transport->remote->name,
-				 connectivity_checked,
-				 ref_map);
+	ret = store_updated_refs(transport->url, transport->remote->name,
+				 connectivity_checked, ref_map, worktrees);
 	trace2_region_leave("fetch", "consume_refs", the_repository);
 
 out:
@@ -1385,19 +1388,18 @@ static int prune_refs(struct refspec *rs, struct ref *ref_map,
 	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)
 {
-	struct branch *current_branch = branch_get(NULL);
-
-	if (is_bare_repository() || !current_branch)
-		return;
-
+	const struct worktree *wt;
 	for (; ref_map; ref_map = ref_map->next)
-		if (ref_map->peer_ref && !strcmp(current_branch->refname,
-					ref_map->peer_ref->name))
-			die(_("refusing to fetch into current branch %s "
-			      "of non-bare repository"),
-			    current_branch->refname);
+		if (ref_map->peer_ref &&
+		    (wt = find_shared_symref(worktrees, "HEAD",
+					     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);
 }
 
 static int truncate_fetch_head(void)
@@ -1495,7 +1497,8 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 	return transport;
 }
 
-static void backfill_tags(struct transport *transport, struct ref *ref_map)
+static void backfill_tags(struct transport *transport, struct ref *ref_map,
+			  struct worktree **worktrees)
 {
 	int cannot_reuse;
 
@@ -1516,7 +1519,7 @@ static void backfill_tags(struct transport *transport, struct ref *ref_map)
 	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);
-	fetch_and_consume_refs(transport, ref_map);
+	fetch_and_consume_refs(transport, ref_map, worktrees);
 
 	if (gsecondary) {
 		transport_disconnect(gsecondary);
@@ -1534,6 +1537,7 @@ 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();
 
 	if (tags == TAGS_DEFAULT) {
 		if (transport->remote->fetch_tags == 2)
@@ -1589,7 +1593,7 @@ 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);
+		check_not_current_branch(ref_map, worktrees);
 
 	if (tags == TAGS_DEFAULT && autotags)
 		transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
@@ -1607,7 +1611,7 @@ static int do_fetch(struct transport *transport,
 				   transport->url);
 		}
 	}
-	if (fetch_and_consume_refs(transport, ref_map)) {
+	if (fetch_and_consume_refs(transport, ref_map, worktrees)) {
 		free_refs(ref_map);
 		retcode = 1;
 		goto cleanup;
@@ -1656,7 +1660,7 @@ static int do_fetch(struct transport *transport,
 				  "you need to specify exactly one branch with the --set-upstream option"));
 		}
 	}
- skip:
+skip:
 	free_refs(ref_map);
 
 	/* if neither --no-tags nor --tags was specified, do automated tag
@@ -1666,11 +1670,12 @@ static int do_fetch(struct transport *transport,
 		ref_map = NULL;
 		find_non_local_tags(remote_refs, &ref_map, &tail);
 		if (ref_map)
-			backfill_tags(transport, ref_map);
+			backfill_tags(transport, ref_map, worktrees);
 		free_refs(ref_map);
 	}
 
- cleanup:
+cleanup:
+	free_worktrees(worktrees);
 	return retcode;
 }
 
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 8212ca56dc..f07e32126f 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1771,4 +1771,22 @@ test_expect_success 'denyCurrentBranch and worktrees' '
 	git -C cloned push origin HEAD:new-wt &&
 	test_must_fail git -C cloned push --delete origin new-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

-- 
2.34.1
Previous: Anders KaseorgNext: Eric Sunshine
Message 12 of 20 in “protect branches checked out in all worktrees”
  1. 0/8 protect branches checked out in all worktreesAnders Kaseorg, Dec 1, 2021
  2. 1/8 fetch: lowercase error messagesAnders Kaseorg, Dec 1, 2021
  3. 3/8 branch: lowercase error messagesAnders Kaseorg, Dec 1, 2021
  4. 4/8 worktree: simplify find_shared_symref() memory ownership modelAnders Kaseorg, Dec 1, 2021
  5. Eric SunshineDec 1, 2021
  6. Anders KaseorgDec 1, 2021
  7. Eric SunshineDec 2, 2021
  8. Eric SunshineDec 2, 2021
  9. Anders KaseorgDec 2, 2021
  10. Eric SunshineDec 2, 2021
  11. 2/8 receive-pack: lowercase error messagesAnders Kaseorg, Dec 1, 2021
  12. 5/8 fetch: protect branches checked out in all worktreesAnders Kaseorg, Dec 1, 2021
  13. Eric SunshineDec 2, 2021
  14. Anders KaseorgDec 2, 2021
  15. 6/8 receive-pack: clean dead code from update_worktree()Anders Kaseorg, Dec 1, 2021
  16. 7/8 receive-pack: protect current branch for bare repository worktreeAnders Kaseorg, Dec 1, 2021
  17. 8/8 branch: protect branches checked out in all worktreesAnders Kaseorg, Dec 1, 2021
  18. Jiang XinDec 23, 2021
  19. Jiang XinJan 12, 2022
  20. Junio C HamanoJan 12, 2022

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.