submodule--helper: add push-check subcommand

Add the 'push-check' subcommand to submodule--helper which is used to
check if the provided remote and refspec can be used as part of a push
operation in the submodule.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 85aafe46a463c651eb09d540ea9ffa0cfcd4a796..6ee962207c4e38f3135f26ff8e0fdca98fa81fa1 100644 (file)
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1105,6 +1105,50 @@ static int resolve_remote_submodule_branch(int argc, const char **argv,
        return 0;
 }
 
+static int push_check(int argc, const char **argv, const char *prefix)
+{
+       struct remote *remote;
+
+       if (argc < 2)
+               die("submodule--helper push-check requires at least 1 argument");
+
+       /*
+        * The remote must be configured.
+        * This is to avoid pushing to the exact same URL as the parent.
+        */
+       remote = pushremote_get(argv[1]);
+       if (!remote || remote->origin == REMOTE_UNCONFIGURED)
+               die("remote '%s' not configured", argv[1]);
+
+       /* Check the refspec */
+       if (argc > 2) {
+               int i, refspec_nr = argc - 2;
+               struct ref *local_refs = get_local_heads();
+               struct refspec *refspec = parse_push_refspec(refspec_nr,
+                                                            argv + 2);
+
+               for (i = 0; i < refspec_nr; i++) {
+                       struct refspec *rs = refspec + i;
+
+                       if (rs->pattern || rs->matching)
+                               continue;
+
+                       /*
+                        * LHS must match a single ref
+                        * NEEDSWORK: add logic to special case 'HEAD' once
+                        * working with submodules in a detached head state
+                        * ceases to be the norm.
+                        */
+                       if (count_refspec_match(rs->src, local_refs, NULL) != 1)
+                               die("src refspec '%s' must name a ref",
+                                   rs->src);
+               }
+               free_refspec(refspec_nr, refspec);
+       }
+
+       return 0;
+}
+
 static int absorb_git_dirs(int argc, const char **argv, const char *prefix)
 {
        int i;
@@ -1170,6 +1214,7 @@ static struct cmd_struct commands[] = {
        {"resolve-relative-url-test", resolve_relative_url_test, 0},
        {"init", module_init, SUPPORT_SUPER_PREFIX},
        {"remote-branch", resolve_remote_submodule_branch, 0},
+       {"push-check", push_check, 0},
        {"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
        {"is-active", is_active, 0},
 };