Merge branch 'nd/per-worktree-ref-iteration'

The code to traverse objects for reachability, used to decide what
objects are unreferenced and expendable, have been taught to also
consider per-worktree refs of other worktrees as starting points to
prevent data loss.

* nd/per-worktree-ref-iteration:
  git-worktree.txt: correct linkgit command name
  reflog expire: cover reflog from all worktrees
  fsck: check HEAD and reflog from other worktrees
  fsck: move fsck_head_link() to get_default_heads() to avoid some globals
  revision.c: better error reporting on ref from different worktrees
  revision.c: correct a parameter name
  refs: new ref types to make per-worktree refs visible to all worktrees
  Add a place for (not) sharing stuff between worktrees
  refs.c: indent with tabs, not spaces

1 files changed, 39 insertions, 3 deletions

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 16ef9325e0..9183875dad 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -10,6 +10,7 @@
 #include "../object.h"
 #include "../dir.h"
 #include "../chdir-notify.h"
+#include "worktree.h"
 
 /*
  * This backend uses the following flags in `ref_update::flags` for
@@ -149,6 +150,25 @@ static struct files_ref_store *files_downcast(struct ref_store *ref_store,
 	return refs;
 }
 
+static void files_reflog_path_other_worktrees(struct files_ref_store *refs,
+					      struct strbuf *sb,
+					      const char *refname)
+{
+	const char *real_ref;
+	const char *worktree_name;
+	int length;
+
+	if (parse_worktree_ref(refname, &worktree_name, &length, &real_ref))
+		BUG("refname %s is not a other-worktree ref", refname);
+
+	if (worktree_name)
+		strbuf_addf(sb, "%s/worktrees/%.*s/logs/%s", refs->gitcommondir,
+			    length, worktree_name, real_ref);
+	else
+		strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir,
+			    real_ref);
+}
+
 static void files_reflog_path(struct files_ref_store *refs,
 			      struct strbuf *sb,
 			      const char *refname)
@@ -158,6 +178,9 @@ static void files_reflog_path(struct files_ref_store *refs,
 	case REF_TYPE_PSEUDOREF:
 		strbuf_addf(sb, "%s/logs/%s", refs->gitdir, refname);
 		break;
+	case REF_TYPE_OTHER_PSEUDOREF:
+	case REF_TYPE_MAIN_PSEUDOREF:
+		return files_reflog_path_other_worktrees(refs, sb, refname);
 	case REF_TYPE_NORMAL:
 		strbuf_addf(sb, "%s/logs/%s", refs->gitcommondir, refname);
 		break;
@@ -176,6 +199,11 @@ static void files_ref_path(struct files_ref_store *refs,
 	case REF_TYPE_PSEUDOREF:
 		strbuf_addf(sb, "%s/%s", refs->gitdir, refname);
 		break;
+	case REF_TYPE_MAIN_PSEUDOREF:
+		if (!skip_prefix(refname, "main-worktree/", &refname))
+			BUG("ref %s is not a main pseudoref", refname);
+		/* fallthrough */
+	case REF_TYPE_OTHER_PSEUDOREF:
 	case REF_TYPE_NORMAL:
 		strbuf_addf(sb, "%s/%s", refs->gitcommondir, refname);
 		break;
@@ -269,9 +297,9 @@ static void loose_fill_ref_dir(struct ref_store *ref_store,
 	closedir(d);
 
 	/*
-	 * Manually add refs/bisect, which, being per-worktree, might
-	 * not appear in the directory listing for refs/ in the main
-	 * repo.
+	 * Manually add refs/bisect and refs/worktree, which, being
+	 * per-worktree, might not appear in the directory listing for
+	 * refs/ in the main repo.
 	 */
 	if (!strcmp(dirname, "refs/")) {
 		int pos = search_ref_dir(dir, "refs/bisect/", 12);
@@ -281,6 +309,14 @@ static void loose_fill_ref_dir(struct ref_store *ref_store,
 					dir->cache, "refs/bisect/", 12, 1);
 			add_entry_to_dir(dir, child_entry);
 		}
+
+		pos = search_ref_dir(dir, "refs/worktree/", 11);
+
+		if (pos < 0) {
+			struct ref_entry *child_entry = create_dir_entry(
+					dir->cache, "refs/worktree/", 11, 1);
+			add_entry_to_dir(dir, child_entry);
+		}
 	}
 }