checkout: allow dwim for branch creation for "git checkout $branch --"
The "--" notation disambiguates files and branches, but as a side-effect of the previous implementation, also disabled the branch auto-creation when $branch does not exist. A possible scenario is then: git checkout $branch => fails if $branch is both a ref and a file, and suggests -- git checkout $branch -- => refuses to create the $branch This patch allows the second form to create $branch, and since the -- is provided, it does not look for file named $branch. Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Matthieu Moy committed
Oct 18, 2013 at 11:25 UTC
a047fafc7866cc4087201e284dc1f53e8f9a32d5
2 files changed
+76
-23
builtin/checkout.c
+55
-23
@@ -884,20 +884,30 @@ static int parse_branchname_arg(int argc, const char **argv,
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*
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* everything after the '--' must be paths.
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*
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- * case 3: git checkout <something> [<paths>]
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+ * case 3: git checkout <something> [--]
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*
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- * With no paths, if <something> is a commit, that is to
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- * switch to the branch or detach HEAD at it. As a special case,
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- * if <something> is A...B (missing A or B means HEAD but you can
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- * omit at most one side), and if there is a unique merge base
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- * between A and B, A...B names that merge base.
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+ * (a) If <something> is a commit, that is to
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+ * switch to the branch or detach HEAD at it. As a special case,
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+ * if <something> is A...B (missing A or B means HEAD but you can
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+ * omit at most one side), and if there is a unique merge base
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+ * between A and B, A...B names that merge base.
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*
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- * With no paths, if <something> is _not_ a commit, no -t nor -b
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- * was given, and there is a tracking branch whose name is
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- * <something> in one and only one remote, then this is a short-hand
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- * to fork local <something> from that remote-tracking branch.
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+ * (b) If <something> is _not_ a commit, either "--" is present
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+ * or <something> is not a path, no -t nor -b was given, and
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+ * and there is a tracking branch whose name is <something>
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+ * in one and only one remote, then this is a short-hand to
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+ * fork local <something> from that remote-tracking branch.
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*
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- * Otherwise <something> shall not be ambiguous.
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+ * (c) Otherwise, if "--" is present, treat it like case (1).
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+ *
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+ * (d) Otherwise :
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+ * - if it's a reference, treat it like case (1)
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+ * - else if it's a path, treat it like case (2)
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+ * - else: fail.
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+ *
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+ * case 4: git checkout <something> <paths>
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+ *
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+ * The first argument must not be ambiguous.
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* - If it's *only* a reference, treat it like case (1).
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* - If it's only a path, treat it like case (2).
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* - else: fail.
@@ -916,18 +926,40 @@ static int parse_branchname_arg(int argc, const char **argv,
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arg = "@{-1}";
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if (get_sha1_mb(arg, rev)) {
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- if (has_dash_dash) /* case (1) */
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- die(_("invalid reference: %s"), arg);
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- if (dwim_new_local_branch_ok &&
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- !check_filename(NULL, arg) &&
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- argc == 1) {
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+ /*
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+ * Either case (3) or (4), with <something> not being
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+ * a commit, or an attempt to use case (1) with an
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+ * invalid ref.
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+ *
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+ * It's likely an error, but we need to find out if
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+ * we should auto-create the branch, case (3).(b).
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+ */
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+ int recover_with_dwim = dwim_new_local_branch_ok;
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+
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+ if (check_filename(NULL, arg) && !has_dash_dash)
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+ recover_with_dwim = 0;
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+ /*
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+ * Accept "git checkout foo" and "git checkout foo --"
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+ * as candidates for dwim.
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+ */
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+ if (!(argc == 1 && !has_dash_dash) &&
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+ !(argc == 2 && has_dash_dash))
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+ recover_with_dwim = 0;
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+
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+ if (recover_with_dwim) {
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const char *remote = unique_tracking_name(arg, rev);
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- if (!remote)
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- return argcount;
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- *new_branch = arg;
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- arg = remote;
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- /* DWIMmed to create local branch */
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- } else {
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+ if (remote) {
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+ *new_branch = arg;
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+ arg = remote;
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+ /* DWIMmed to create local branch, case (3).(b) */
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+ } else {
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+ recover_with_dwim = 0;
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+ }
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+ }
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+
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+ if (!recover_with_dwim) {
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+ if (has_dash_dash)
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+ die(_("invalid reference: %s"), arg);
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return argcount;
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}
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}
@@ -957,7 +989,7 @@ static int parse_branchname_arg(int argc, const char **argv,
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if (!*source_tree) /* case (1): want a tree */
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die(_("reference is not a tree: %s"), arg);
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- if (!has_dash_dash) {/* case (3 -> 1) */
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+ if (!has_dash_dash) {/* case (3).(d) -> (1) */
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/*
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* Do not complain the most common case
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* git checkout branch
t/t2024-checkout-dwim.sh
+21
@@ -164,4 +164,25 @@ test_expect_success 'checkout of branch from a single remote succeeds #4' '
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test_branch_upstream eggs repo_d eggs
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'
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+test_expect_success 'checkout of branch with a file having the same name fails' '
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+ git checkout -B master &&
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+ test_might_fail git branch -D spam &&
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+
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+ >spam &&
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+ test_must_fail git checkout spam &&
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+ test_must_fail git rev-parse --verify refs/heads/spam &&
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+ test_branch master
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+'
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+
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+test_expect_success 'checkout <branch> -- succeeds, even if a file with the same name exists' '
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+ git checkout -B master &&
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+ test_might_fail git branch -D spam &&
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+
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+ >spam &&
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+ git checkout spam -- &&
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+ test_branch spam &&
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+ test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
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+ test_branch_upstream spam repo_c spam
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+'
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+
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test_done