worktree: make add <path> <branch> dwim

diff --git a/builtin/worktree.c b/builtin/worktree.c
index ea9678cac8a56a523b39e6a7fbbcd1edb1ad681c..7021d025851a48ad8e05406394240091e0a78e41 100644 (file)
--- a/builtin/worktree.c
+++ b/builtin/worktree.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "checkout.h"
 #include "config.h"
 #include "builtin.h"
 #include "dir.h"
@@ -390,6 +391,21 @@ static int add(int ac, const char **av, const char *prefix)
                opts.new_branch = xstrndup(s, n);
        }
 
+       if (ac == 2 && !opts.new_branch && !opts.detach) {
+               struct object_id oid;
+               struct commit *commit;
+               const char *remote;
+
+               commit = lookup_commit_reference_by_name(branch);
+               if (!commit) {
+                       remote = unique_tracking_name(branch, &oid);
+                       if (remote) {
+                               opts.new_branch = branch;
+                               branch = remote;
+                       }
+               }
+       }
+
        if (opts.new_branch) {
                struct child_process cp = CHILD_PROCESS_INIT;
                cp.git_cmd = 1;