Merge branch 'mm/checkout-auto-track-fix' into maint

"git checkout topic", when there is not yet a local "topic" branch
but there is a unique remote-tracking branch for a remote "topic"
branch, pretended as if "git checkout -t -b topic remote/$r/topic"
(for that unique remote $r) was run. This hack however was not
implemented for "git checkout topic --".

* mm/checkout-auto-track-fix:
checkout: proper error message on 'git checkout foo bar --'
checkout: allow dwim for branch creation for "git checkout $branch --"

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 7025938ae30f2ce3104b27f66bf6e1f294edb810..22cc7fcb59a508c861dd2b55b4c591c8792f8fdc 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -880,7 +880,9 @@ static int parse_branchname_arg(int argc, const char **argv,
        int argcount = 0;
        unsigned char branch_rev[20];
        const char *arg;
-       int has_dash_dash;
+       int dash_dash_pos;
+       int has_dash_dash = 0;
+       int i;
 
        /*
         * case 1: git checkout <ref> -- [<paths>]
@@ -892,20 +894,30 @@ static int parse_branchname_arg(int argc, const char **argv,
         *
         *   everything after the '--' must be paths.
         *
-        * case 3: git checkout <something> [<paths>]
+        * case 3: git checkout <something> [--]
         *
-        *   With no paths, 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.
+        *   (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.
         *
-        *   With no paths, if <something> is _not_ a commit, no -t nor -b
-        *   was given, and there is a tracking branch whose name is
-        *   <something> in one and only one remote, then this is a short-hand
-        *   to fork local <something> from that remote-tracking branch.
+        *   (b) If <something> is _not_ a commit, either "--" is present
+        *       or <something> is not a path, no -t nor -b was given, and
+        *       and there is a tracking branch whose name is <something>
+        *       in one and only one remote, then this is a short-hand to
+        *       fork local <something> from that remote-tracking branch.
         *
-        *   Otherwise <something> shall not be ambiguous.
+        *   (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.
@@ -914,28 +926,59 @@ static int parse_branchname_arg(int argc, const char **argv,
        if (!argc)
                return 0;
 
-       if (!strcmp(argv[0], "--"))     /* case (2) */
-               return 1;
-
        arg = argv[0];
-       has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
+       dash_dash_pos = -1;
+       for (i = 0; i < argc; i++) {
+               if (!strcmp(argv[i], "--")) {
+                       dash_dash_pos = i;
+                       break;
+               }
+       }
+       if (dash_dash_pos == 0)
+               return 1; /* case (2) */
+       else if (dash_dash_pos == 1)
+               has_dash_dash = 1; /* case (3) or (1) */
+       else if (dash_dash_pos >= 2)
+               die(_("only one reference expected, %d given."), dash_dash_pos);
 
        if (!strcmp(arg, "-"))
                arg = "@{-1}";
 
        if (get_sha1_mb(arg, rev)) {
-               if (has_dash_dash)          /* case (1) */
-                       die(_("invalid reference: %s"), arg);
-               if (dwim_new_local_branch_ok &&
-                   !check_filename(NULL, arg) &&
-                   argc == 1) {
+               /*
+                * 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;
+
+               if (check_filename(NULL, arg) && !has_dash_dash)
+                       recover_with_dwim = 0;
+               /*
+                * Accept "git checkout foo" and "git checkout foo --"
+                * as candidates for dwim.
+                */
+               if (!(argc == 1 && !has_dash_dash) &&
+                   !(argc == 2 && has_dash_dash))
+                       recover_with_dwim = 0;
+
+               if (recover_with_dwim) {
                        const char *remote = unique_tracking_name(arg, rev);
-                       if (!remote)
-                               return argcount;
-                       *new_branch = arg;
-                       arg = remote;
-                       /* DWIMmed to create local branch */
-               } else {
+                       if (remote) {
+                               *new_branch = arg;
+                               arg = remote;
+                               /* DWIMmed to create local branch, case (3).(b) */
+                       } else {
+                               recover_with_dwim = 0;
+                       }
+               }
+
+               if (!recover_with_dwim) {
+                       if (has_dash_dash)
+                               die(_("invalid reference: %s"), arg);
                        return argcount;
                }
        }
@@ -965,7 +1008,7 @@ static int parse_branchname_arg(int argc, const char **argv,
 
        if (!*source_tree)                   /* case (1): want a tree */
                die(_("reference is not a tree: %s"), arg);
-       if (!has_dash_dash) {/* case (3 -> 1) */
+       if (!has_dash_dash) {/* case (3).(d) -> (1) */
                /*
                 * Do not complain the most common case
                 *      git checkout branch

diff --git a/t/t2010-checkout-ambiguous.sh b/t/t2010-checkout-ambiguous.sh
index 7cc0a3582ef1bb1598bc5dfc5334bfbe006c3f5a..87bdf9c96bfacf4ac921ad9b195db46d9c3b079a 100755 (executable)
--- a/t/t2010-checkout-ambiguous.sh
+++ b/t/t2010-checkout-ambiguous.sh
@@ -47,4 +47,10 @@ test_expect_success 'disambiguate checking out from a tree-ish' '
        git diff --exit-code --quiet
 '
 
+test_expect_success 'accurate error message with more than one ref' '
+       test_must_fail git checkout HEAD master -- 2>actual &&
+       grep 2 actual &&
+       test_i18ngrep "one reference expected, 2 given" actual
+'
+
 test_done

diff --git a/t/t2024-checkout-dwim.sh b/t/t2024-checkout-dwim.sh
index 094b92ef489156980dc1429136d5dad25d01ac7d..6ecb559465b43e528a5cb1511b758cc48d940e92 100755 (executable)
--- a/t/t2024-checkout-dwim.sh
+++ b/t/t2024-checkout-dwim.sh
@@ -164,4 +164,25 @@ test_expect_success 'checkout of branch from a single remote succeeds #4' '
        test_branch_upstream eggs repo_d eggs
 '
 
+test_expect_success 'checkout of branch with a file having the same name fails' '
+       git checkout -B master &&
+       test_might_fail git branch -D spam &&
+
+       >spam &&
+       test_must_fail git checkout spam &&
+       test_must_fail git rev-parse --verify refs/heads/spam &&
+       test_branch master
+'
+
+test_expect_success 'checkout <branch> -- succeeds, even if a file with the same name exists' '
+       git checkout -B master &&
+       test_might_fail git branch -D spam &&
+
+       >spam &&
+       git checkout spam -- &&
+       test_branch spam &&
+       test_cmp_rev refs/remotes/extra_dir/repo_c/extra_dir/spam HEAD &&
+       test_branch_upstream spam repo_c spam
+'
+
 test_done