Merge branch 'nd/worktree-prune'

The way "git worktree prune" worked internally has been simplified,
by assuming how "git worktree move" moves an existing worktree to a
different place.

* nd/worktree-prune:
  worktree prune: improve prune logic when worktree is moved
  worktree: delete dead code
  gc.txt: more details about what gc does

Documentation/git-gc.txt

@@ -15,8 +15,9 @@ DESCRIPTION
 -----------
 Runs a number of housekeeping tasks within the current repository,
 such as compressing file revisions (to reduce disk space and increase
-performance) and removing unreachable objects which may have been
-created from prior invocations of 'git add'.
+performance), removing unreachable objects which may have been
+created from prior invocations of 'git add', packing refs, pruning
+reflog, rerere metadata or stale working trees.
 
 Users are encouraged to run this task on a regular basis within
 each repository to maintain good disk space utilization and good
@@ -45,20 +46,25 @@ OPTIONS
 	With this option, 'git gc' checks whether any housekeeping is
 	required; if not, it exits without performing any work.
 	Some git commands run `git gc --auto` after performing
-	operations that could create many loose objects.
+	operations that could create many loose objects. Housekeeping
+	is required if there are too many loose objects or too many
+	packs in the repository.
 +
-Housekeeping is required if there are too many loose objects or
-too many packs in the repository. If the number of loose objects
-exceeds the value of the `gc.auto` configuration variable, then
-all loose objects are combined into a single pack using
-`git repack -d -l`.  Setting the value of `gc.auto` to 0
-disables automatic packing of loose objects.
+If the number of loose objects exceeds the value of the `gc.auto`
+configuration variable, then all loose objects are combined into a
+single pack using `git repack -d -l`.  Setting the value of `gc.auto`
+to 0 disables automatic packing of loose objects.
 +
 If the number of packs exceeds the value of `gc.autoPackLimit`,
 then existing packs (except those marked with a `.keep` file)
 are consolidated into a single pack by using the `-A` option of
 'git repack'. Setting `gc.autoPackLimit` to 0 disables
 automatic consolidation of packs.
++
+If houskeeping is required due to many loose objects or packs, all
+other housekeeping tasks (e.g. rerere, working trees, reflog...) will
+be performed as well.
+
 
 --prune=<date>::
 	Prune loose objects older than date (default is 2 weeks ago,
@@ -133,6 +139,10 @@ The optional configuration variable `gc.pruneExpire` controls how old
 the unreferenced loose objects have to be before they are pruned.  The
 default is "2 weeks ago".
 
+Optional configuration variable `gc.worktreePruneExpire` controls how
+old a stale working tree should be before `git worktree prune` deletes
+it. Default is "3 months ago".
+
 
 Notes
 -----

Documentation/gitrepository-layout.txt

@@ -275,11 +275,6 @@ worktrees/<id>/locked::
 	or manually by `git worktree prune`. The file may contain a string
 	explaining why the repository is locked.
 
-worktrees/<id>/link::
-	If this file exists, it is a hard link to the linked .git
-	file. It is used to detect if the linked repository is
-	manually removed.
-
 SEE ALSO
 --------
 linkgit:git-init[1],

builtin/worktree.c

@@ -101,16 +101,9 @@ static int prune_worktree(const char *id, struct strbuf *reason)
 	}
 	path[len] = '\0';
 	if (!file_exists(path)) {
-		struct stat st_link;
 		free(path);
-		/*
-		 * the repo is moved manually and has not been
-		 * accessed since?
-		 */
-		if (!stat(git_path("worktrees/%s/link", id), &st_link) &&
-		    st_link.st_nlink > 1)
-			return 0;
-		if (st.st_mtime <= expire) {
+		if (stat(git_path("worktrees/%s/index", id), &st) ||
+		    st.st_mtime <= expire) {
 			strbuf_addf(reason, _("Removing worktrees/%s: gitdir file points to non-existent location"), id);
 			return 1;
 		} else {

t/t2026-worktree-prune.sh

@@ -78,10 +78,9 @@ test_expect_success 'not prune locked checkout' '
 
 test_expect_success 'not prune recent checkouts' '
 	test_when_finished rm -r .git/worktrees &&
-	mkdir zz &&
-	mkdir -p .git/worktrees/jlm &&
-	echo "$(pwd)"/zz >.git/worktrees/jlm/gitdir &&
-	rmdir zz &&
+	git worktree add jlm HEAD &&
+	test -d .git/worktrees/jlm &&
+	rm -rf jlm &&
 	git worktree prune --verbose --expire=2.days.ago &&
 	test -d .git/worktrees/jlm
 '