@@ -1158,45 +1158,21 @@ static int parse_branchname_arg(int argc, const char **argv,
int i;
/*
- * case 1: git checkout <ref> -- [<paths>]
- *
- * <ref> must be a valid tree, everything after the '--' must be
- * a path.
- *
- * case 2: git checkout -- [<paths>]
- *
- * everything after the '--' must be paths.
- *
- * case 3: git checkout <something> [--]
- *
- * (a) If <something> is a commit, that is to
- * switch to the branch or detach HEAD at it. As a special case,
- * if <something> is A...B (missing A or B means HEAD but you can
- * omit at most one side), and if there is a unique merge base
- * between A and B, A...B names that merge base.
- *
- * (b) If <something> is _not_ a commit, either "--" is present
- * or <something> is not a path, no -t or -b was given, and
- * and there is a tracking branch whose name is <something>
- * in one and only one remote (or if the branch exists on the
- * remote named in checkout.defaultRemote), then this is a
- * short-hand to fork local <something> from that
- * remote-tracking branch.
- *
- * (c) Otherwise, if "--" is present, treat it like case (1).
- *
- * (d) Otherwise :
- * - if it's a reference, treat it like case (1)
- * - else if it's a path, treat it like case (2)
- * - else: fail.
- *
- * case 4: git checkout <something> <paths>
- *
- * The first argument must not be ambiguous.
- * - If it's *only* a reference, treat it like case (1).
- * - If it's only a path, treat it like case (2).
- * - else: fail.
- *
+ * Resolve ambiguity where argv[0] may be <pathspec> or <commit>.
+ * High-level approach is:
+ * 1) Use various things to reduce ambiguity, examples:
+ * * '--' is present
+ * * command doesn't accept <pathspec>
+ * * additional options like '-b' were given
+ * 2) If ambiguous and matches both existing <commit> and existing
+ * file, complain. However, in 1-argument 'git checkout <arg>'
+ * treat as <commit> to avoid annoying users.
+ * 3) Otherwise, if it matches some existing <commit>, treat as
+ * <commit>.
+ * 4) Otherwise, if it matches a remote branch, and it's considered
+ * reasonable to DWIM to create a local branch from remote branch,
+ * do that and proceed with (2)(3).
+ * 5) Otherwise, let caller proceed with <pathspec> interpretation.
*/
if (!argc)
return 0;
@@ -1218,9 +1194,9 @@ static int parse_branchname_arg(int argc, const char **argv,
if (opts->accept_pathspec) {
if (dash_dash_pos == 0)
- return 1; /* case (2) */
+ return 1;
else if (dash_dash_pos == 1)
- has_dash_dash = 1; /* case (3) or (1) */
+ has_dash_dash = 1;
else if (dash_dash_pos >= 2)
die(_("only one reference expected, %d given."), dash_dash_pos);
}
@@ -1234,14 +1210,6 @@ static int parse_branchname_arg(int argc, const char **argv,
arg = "@{-1}";
if (get_oid_mb(arg, rev)) {
- /*
- * Either case (3) or (4), with <something> not being
- * a commit, or an attempt to use case (1) with an
- * invalid ref.
- *
- * It's likely an error, but we need to find out if
- * we should auto-create the branch, case (3).(b).
- */
int recover_with_dwim = dwim_new_local_branch_ok;
int could_be_checkout_paths = !expect_commit_only &&
@@ -1250,10 +1218,6 @@ static int parse_branchname_arg(int argc, const char **argv,
if (!expect_commit_only && !no_wildcard(arg))
recover_with_dwim = 0;
- /*
- * Accept "git checkout foo", "git checkout foo --"
- * and "git switch foo" as candidates for dwim.
- */
if (!(argc == 1 && !has_dash_dash) &&
!(argc == 2 && has_dash_dash) &&
opts->accept_pathspec)
@@ -1265,7 +1229,7 @@ static int parse_branchname_arg(int argc, const char **argv,
if (remote) {
*new_branch = arg;
arg = remote;
- /* DWIMmed to create local branch, case (3).(b) */
+ /* DWIMmed to create local branch */
} else {
recover_with_dwim = 0;
}
@@ -1280,19 +1244,11 @@ static int parse_branchname_arg(int argc, const char **argv,
setup_new_branch_info_and_source_tree(new_branch_info, opts, rev, arg);
- if (!opts->source_tree) /* case (1): want a tree */
+ if (!opts->source_tree)
die(_("reference is not a tree: %s"), arg);
- if (!expect_commit_only) { /* case (3).(d) -> (1) */
- /*
- * Do not complain the most common case
- * git checkout branch
- * even if there happen to be a file called 'branch';
- * it would be extremely annoying.
- */
- if (argc > 1)
- verify_non_filename(opts->prefix, arg);
- }
+ if (!expect_commit_only && argc > 1)
+ verify_non_filename(opts->prefix, arg);
return (dash_dash_pos == 1) ? 2 : 1;
}