branch -m: update all per-worktree HEADs

When renaming a branch, currently only the HEAD of current working tree
is updated, but it must update HEADs of all working trees which point at
the old branch.

This is the current behavior, /path/to/wt's HEAD is not updated:

  % git worktree list
  /path/to     2c3c5f2 [master]
  /path/to/wt  2c3c5f2 [oldname]
  % git branch -m master master2
  % git worktree list
  /path/to     2c3c5f2 [master2]
  /path/to/wt  2c3c5f2 [oldname]
  % git branch -m oldname newname
  % git worktree list
  /path/to     2c3c5f2 [master2]
  /path/to/wt  0000000 [oldname]

This patch fixes this issue by updating all relevant worktree HEADs
when renaming a branch.

Signed-off-by: Kazuki Yamaguchi <k@rhe.jp>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/branch.c b/branch.c
index c50ea42..4162443 100644 (file)
--- a/branch.c
+++ b/branch.c
@@ -344,3 +344,26 @@ void die_if_checked_out(const char *branch)
                die(_("'%s' is already checked out at '%s'"), branch, existing);
        }
 }
+
+int replace_each_worktree_head_symref(const char *oldref, const char *newref)
+{
+       int ret = 0;
+       struct worktree **worktrees = get_worktrees();
+       int i;
+
+       for (i = 0; worktrees[i]; i++) {
+               if (worktrees[i]->is_detached)
+                       continue;
+               if (strcmp(oldref, worktrees[i]->head_ref))
+                       continue;
+
+               if (set_worktree_head_symref(worktrees[i]->git_dir, newref)) {
+                       ret = -1;
+                       error(_("HEAD of working tree %s is not updated"),
+                             worktrees[i]->path);
+               }
+       }
+
+       free_worktrees(worktrees);
+       return ret;
+}

diff --git a/branch.h b/branch.h
index 78ad438..d69163d 100644 (file)
--- a/branch.h
+++ b/branch.h
@@ -60,4 +60,11 @@ extern int read_branch_desc(struct strbuf *, const char *branch_name);
  */
 extern void die_if_checked_out(const char *branch);
 
+/*
+ * Update all per-worktree HEADs pointing at the old ref to point the new ref.
+ * This will be used when renaming a branch. Returns 0 if successful, non-zero
+ * otherwise.
+ */
+extern int replace_each_worktree_head_symref(const char *oldref, const char *newref);
+
 #endif

diff --git a/builtin/branch.c b/builtin/branch.c
index 7b45b6b..b173831 100644 (file)
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -552,8 +552,7 @@ static void rename_branch(const char *oldname, const char *newname, int force)
        if (recovery)
                warning(_("Renamed a misnamed branch '%s' away"), oldref.buf + 11);
 
-       /* no need to pass logmsg here as HEAD didn't really move */
-       if (!strcmp(oldname, head) && create_symref("HEAD", newref.buf, NULL))
+       if (replace_each_worktree_head_symref(oldref.buf, newref.buf))
                die(_("Branch renamed to %s, but HEAD is not updated!"), newname);
 
        strbuf_addf(&oldsection, "branch.%s", oldref.buf + 11);

diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index a897248..f7d438b 100755 (executable)
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -126,7 +126,28 @@ test_expect_success 'git branch -M foo bar should fail when bar is checked out'
 test_expect_success 'git branch -M baz bam should succeed when baz is checked out' '
        git checkout -b baz &&
        git branch bam &&
-       git branch -M baz bam
+       git branch -M baz bam &&
+       test $(git rev-parse --abbrev-ref HEAD) = bam
+'
+
+test_expect_success 'git branch -M baz bam should succeed when baz is checked out as linked working tree' '
+       git checkout master &&
+       git worktree add -b baz bazdir &&
+       git worktree add -f bazdir2 baz &&
+       git branch -M baz bam &&
+       test $(git -C bazdir rev-parse --abbrev-ref HEAD) = bam &&
+       test $(git -C bazdir2 rev-parse --abbrev-ref HEAD) = bam
+'
+
+test_expect_success 'git branch -M baz bam should succeed within a worktree in which baz is checked out' '
+       git checkout -b baz &&
+       git worktree add -f bazdir3 baz &&
+       (
+               cd bazdir3 &&
+               git branch -M baz bam &&
+               test $(git rev-parse --abbrev-ref HEAD) = bam
+       ) &&
+       test $(git rev-parse --abbrev-ref HEAD) = bam
 '
 
 test_expect_success 'git branch -M master should work when master is checked out' '