wt-status.c: split bisect detection out of wt_status_get_state()

And make it work with any given worktree, in preparation for (again)
find_shared_symref(). read_and_strip_branch() is deleted because it's
no longer used.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pclouds

wt-status.c

@@ -1296,11 +1296,6 @@ static char *get_branch(const struct worktree *wt, const char *path)
 	return NULL;
 }
 
-static char *read_and_strip_branch(const char *path)
-{
-	return get_branch(NULL, path);
-}
-
 struct grab_1st_switch_cbdata {
 	struct strbuf buf;
 	unsigned char nsha1[20];
@@ -1393,6 +1388,19 @@ int wt_status_check_rebase(const struct worktree *wt,
 	return 1;
 }
 
+int wt_status_check_bisect(const struct worktree *wt,
+			   struct wt_status_state *state)
+{
+	struct stat st;
+
+	if (!stat(worktree_git_path(wt, "BISECT_LOG"), &st)) {
+		state->bisect_in_progress = 1;
+		state->branch = get_branch(wt, "BISECT_START");
+		return 1;
+	}
+	return 0;
+}
+
 void wt_status_get_state(struct wt_status_state *state,
 			 int get_detached_from)
 {
@@ -1408,10 +1416,7 @@ void wt_status_get_state(struct wt_status_state *state,
 		state->cherry_pick_in_progress = 1;
 		hashcpy(state->cherry_pick_head_sha1, sha1);
 	}
-	if (!stat(git_path("BISECT_LOG"), &st)) {
-		state->bisect_in_progress = 1;
-		state->branch = read_and_strip_branch("BISECT_START");
-	}
+	wt_status_check_bisect(NULL, state);
 	if (!stat(git_path_revert_head(), &st) &&
 	    !get_sha1("REVERT_HEAD", sha1)) {
 		state->revert_in_progress = 1;

wt-status.h

@@ -104,6 +104,8 @@ void wt_status_collect(struct wt_status *s);
 void wt_status_get_state(struct wt_status_state *state, int get_detached_from);
 int wt_status_check_rebase(const struct worktree *wt,
 			   struct wt_status_state *state);
+int wt_status_check_bisect(const struct worktree *wt,
+			   struct wt_status_state *state);
 
 void wt_shortstatus_print(struct wt_status *s);
 void wt_porcelain_print(struct wt_status *s);