submodule: support reading .gitmodules when it's not in the working tree

diff --git a/submodule.c b/submodule.c
index 939d6870ecd7cfbc62f9fa3fb867e5c7362ed9bd..2b7082b2dbba735d81998dd4a31b1dbe9ab6b14f 100644 (file)
--- a/submodule.c
+++ b/submodule.c
@@ -50,6 +50,24 @@ int is_gitmodules_unmerged(const struct index_state *istate)
        return 0;
 }
 
+/*
+ * Check if the .gitmodules file is safe to write.
+ *
+ * Writing to the .gitmodules file requires that the file exists in the
+ * working tree or, if it doesn't, that a brand new .gitmodules file is going
+ * to be created (i.e. it's neither in the index nor in the current branch).
+ *
+ * It is not safe to write to .gitmodules if it's not in the working tree but
+ * it is in the index or in the current branch, because writing new values
+ * (and staging them) would blindly overwrite ALL the old content.
+ */
+int is_writing_gitmodules_ok(void)
+{
+       struct object_id oid;
+       return file_exists(GITMODULES_FILE) ||
+               (get_oid(GITMODULES_INDEX, &oid) < 0 && get_oid(GITMODULES_HEAD, &oid) < 0);
+}
+
 /*
  * Check if the .gitmodules file has unstaged modifications.  This must be
  * checked before allowing modifications to the .gitmodules file with the
@@ -89,11 +107,12 @@ int update_path_in_gitmodules(const char *oldpath, const char *newpath)
 {
        struct strbuf entry = STRBUF_INIT;
        const struct submodule *submodule;
+       int ret;
 
        if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
                return -1;
 
-       if (is_gitmodules_unmerged(&the_index))
+       if (is_gitmodules_unmerged(the_repository->index))
                die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 
        submodule = submodule_from_path(the_repository, &null_oid, oldpath);
@@ -104,14 +123,9 @@ int update_path_in_gitmodules(const char *oldpath, const char *newpath)
        strbuf_addstr(&entry, "submodule.");
        strbuf_addstr(&entry, submodule->name);
        strbuf_addstr(&entry, ".path");
-       if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
-               /* Maybe the user already did that, don't error out here */
-               warning(_("Could not update .gitmodules entry %s"), entry.buf);
-               strbuf_release(&entry);
-               return -1;
-       }
+       ret = config_set_in_gitmodules_file_gently(entry.buf, newpath);
        strbuf_release(&entry);
-       return 0;
+       return ret;
 }
 
 /*
@@ -127,7 +141,7 @@ int remove_path_from_gitmodules(const char *path)
        if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
                return -1;
 
-       if (is_gitmodules_unmerged(&the_index))
+       if (is_gitmodules_unmerged(the_repository->index))
                die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 
        submodule = submodule_from_path(the_repository, &null_oid, path);
@@ -188,7 +202,7 @@ void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 
                if (ignore)
                        handle_ignore_submodules_arg(diffopt, ignore);
-               else if (is_gitmodules_unmerged(&the_index))
+               else if (is_gitmodules_unmerged(the_repository->index))
                        diffopt->flags.ignore_submodules = 1;
        }
 }
@@ -258,7 +272,7 @@ int is_submodule_active(struct repository *repo, const char *path)
                }
 
                parse_pathspec(&ps, 0, 0, NULL, args.argv);
-               ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
+               ret = match_pathspec(repo->index, &ps, path, strlen(path), 0, NULL, 1);
 
                argv_array_clear(&args);
                clear_pathspec(&ps);
@@ -517,8 +531,8 @@ static void show_submodule_header(struct diff_options *o, const char *path,
         * Attempt to lookup the commit references, and determine if this is
         * a fast forward or fast backwards update.
         */
-       *left = lookup_commit_reference(one);
-       *right = lookup_commit_reference(two);
+       *left = lookup_commit_reference(the_repository, one);
+       *right = lookup_commit_reference(the_repository, two);
 
        /*
         * Warn about missing commits in the submodule project, but only if
@@ -740,12 +754,14 @@ static void collect_changed_submodules_cb(struct diff_queue_struct *q,
                else {
                        name = default_name_or_path(p->two->path);
                        /* make sure name does not collide with existing one */
-                       submodule = submodule_from_name(the_repository, commit_oid, name);
+                       if (name)
+                               submodule = submodule_from_name(the_repository,
+                                                               commit_oid, name);
                        if (submodule) {
                                warning("Submodule in commit %s at path: "
                                        "'%s' collides with a submodule named "
                                        "the same. Skipping it.",
-                                       oid_to_hex(commit_oid), name);
+                                       oid_to_hex(commit_oid), p->two->path);
                                name = NULL;
                        }
                }
@@ -1668,7 +1684,7 @@ int submodule_move_head(const char *path,
        argv_array_push(&cp.args, new_head ? new_head : empty_tree_oid_hex());
 
        if (run_command(&cp)) {
-               ret = -1;
+               ret = error(_("Submodule '%s' could not be updated."), path);
                goto out;
        }