submodule: refactor to be more explicit in the search

When searching for information about a submdoule, let's be more explicit
in what we expect to find. We currently insert a submodule into the map
and change certain parameters when the config callback gets called.

Switch to asking for the configuration we're interested in, rather than
taking it in an arbitrary order.

1 files changed, 219 insertions, 144 deletions

diff --git a/src/submodule.c b/src/submodule.c
index 7f52c3616..1d73dc24e 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -89,9 +89,11 @@ __KHASH_IMPL(
 
 static int submodule_alloc(git_submodule **out, git_repository *repo, const char *name);
 static git_config_backend *open_gitmodules(git_repository *repo, int gitmod);
+static git_config *gitmodules_snapshot(git_repository *repo);
 static int get_url_base(git_buf *url, git_repository *repo);
 static int lookup_head_remote_key(git_buf *remote_key, git_repository *repo);
-static int submodule_load_from_config(const git_config_entry *, void *);
+static int submodule_load_each(const git_config_entry *entry, void *payload);
+static int submodule_read_config(git_submodule *sm, git_config *cfg);
 static int submodule_load_from_wd_lite(git_submodule *);
 static void submodule_get_index_status(unsigned int *, git_submodule *);
 static void submodule_get_wd_status(unsigned int *, git_submodule *, git_repository *, git_submodule_ignore_t);
@@ -144,6 +146,41 @@ static int find_by_path(const git_config_entry *entry, void *payload)
 	return 0;
 }
 
+/**
+ * Find out the name of a submodule from its path
+ */
+static int name_from_path(git_buf *out, git_config *cfg, const char *path)
+{
+	const char *key = "submodule\\..*\\.path";
+	git_config_iterator *iter;
+	git_config_entry *entry;
+	int error;
+
+	if ((error = git_config_iterator_glob_new(&iter, cfg, key)) < 0)
+		return error;
+
+	while ((error = git_config_next(&entry, iter)) == 0) {
+		const char *fdot, *ldot;
+		/* TODO: this should maybe be strcasecmp on a case-insensitive fs */
+		if (strcmp(path, entry->value) != 0)
+			continue;
+
+		fdot = strchr(entry->name, '.');
+		ldot = strrchr(entry->name, '.');
+
+		git_buf_clear(out);
+		git_buf_put(out, fdot + 1, ldot - fdot - 1);
+		return 0;
+	}
+
+	if (error == GIT_ITEROVER) {
+		giterr_set(GITERR_SUBMODULE, "could not find a submodule name for '%s'", path);
+		error = GIT_ENOTFOUND;
+	}
+
+	return error;
+}
+
 int git_submodule_lookup(
 	git_submodule **out, /* NULL if user only wants to test existence */
 	git_repository *repo,
@@ -280,11 +317,12 @@ done:
 	return 0;
 }
 
-static int submodules_from_index(git_strmap *map, git_index *idx)
+static int submodules_from_index(git_strmap *map, git_index *idx, git_config *cfg)
 {
        int error;
        git_iterator *i;
        const git_index_entry *entry;
+       git_buf name = GIT_BUF_INIT;
 
        if ((error = git_iterator_for_index(&i, idx, NULL)) < 0)
                return error;
@@ -293,6 +331,11 @@ static int submodules_from_index(git_strmap *map, git_index *idx)
                khiter_t pos = git_strmap_lookup_index(map, entry->path);
                git_submodule *sm;
 
+	       git_buf_clear(&name);
+	       if (!name_from_path(&name, cfg, entry->path)) {
+		       git_strmap_lookup_index(map, name.ptr);
+	       }
+
                if (git_strmap_valid_index(map, pos)) {
                        sm = git_strmap_value_at(map, pos);
 
@@ -301,7 +344,7 @@ static int submodules_from_index(git_strmap *map, git_index *idx)
                        else
                                sm->flags |= GIT_SUBMODULE_STATUS__INDEX_NOT_SUBMODULE;
                } else if (S_ISGITLINK(entry->mode)) {
-                       if (!submodule_get_or_create(&sm, git_index_owner(idx), map, entry->path)) {
+                       if (!submodule_get_or_create(&sm, git_index_owner(idx), map, name.ptr ? name.ptr : entry->path)) {
                                submodule_update_from_index_entry(sm, entry);
                                git_submodule_free(sm);
                        }
@@ -311,16 +354,18 @@ static int submodules_from_index(git_strmap *map, git_index *idx)
        if (error == GIT_ITEROVER)
                error = 0;
 
+       git_buf_free(&name);
        git_iterator_free(i);
 
        return error;
 }
 
-static int submodules_from_head(git_strmap *map, git_tree *head)
+static int submodules_from_head(git_strmap *map, git_tree *head, git_config *cfg)
 {
        int error;
        git_iterator *i;
        const git_index_entry *entry;
+       git_buf name = GIT_BUF_INIT;
 
        if ((error = git_iterator_for_tree(&i, head, NULL)) < 0)
                return error;
@@ -329,6 +374,11 @@ static int submodules_from_head(git_strmap *map, git_tree *head)
                khiter_t pos = git_strmap_lookup_index(map, entry->path);
                git_submodule *sm;
 
+	       git_buf_clear(&name);
+	       if (!name_from_path(&name, cfg, entry->path)) {
+		       git_strmap_lookup_index(map, name.ptr);
+	       }
+
                if (git_strmap_valid_index(map, pos)) {
                        sm = git_strmap_value_at(map, pos);
 
@@ -337,7 +387,7 @@ static int submodules_from_head(git_strmap *map, git_tree *head)
                        else
                                sm->flags |= GIT_SUBMODULE_STATUS__HEAD_NOT_SUBMODULE;
                } else if (S_ISGITLINK(entry->mode)) {
-                       if (!submodule_get_or_create(&sm, git_tree_owner(head), map, entry->path)) {
+                       if (!submodule_get_or_create(&sm, git_tree_owner(head), map, name.ptr ? name.ptr : entry->path)) {
                                submodule_update_from_head_data(
                                        sm, entry->mode, &entry->id);
                                git_submodule_free(sm);
@@ -348,6 +398,7 @@ static int submodules_from_head(git_strmap *map, git_tree *head)
        if (error == GIT_ITEROVER)
                error = 0;
 
+       git_buf_free(&name);
        git_iterator_free(i);
 
        return error;
@@ -355,8 +406,7 @@ static int submodules_from_head(git_strmap *map, git_tree *head)
 
 /* If have_sm is true, sm is populated, otherwise map an repo are. */
 typedef struct {
-	int have_sm;
-	git_submodule *sm;
+	git_config *mods;
 	git_strmap *map;
 	git_repository *repo;
 } lfc_data;
@@ -369,7 +419,7 @@ static int all_submodules(git_repository *repo, git_strmap *map)
 	const char *wd = NULL;
 	git_buf path = GIT_BUF_INIT;
 	git_submodule *sm;
-	git_config_backend *mods = NULL;
+	git_config *mods = NULL;
 	uint32_t mask;
 
 	assert(repo && map);
@@ -400,24 +450,28 @@ static int all_submodules(git_repository *repo, git_strmap *map)
 			GIT_SUBMODULE_STATUS__WD_FLAGS |
 			GIT_SUBMODULE_STATUS__WD_OID_VALID;
 
+	/* add submodule information from .gitmodules */
+	if (wd) {
+		lfc_data data = { 0 };
+		data.map = map;
+		data.repo = repo;
+
+		if ((mods = gitmodules_snapshot(repo)) == NULL)
+			goto cleanup;
+
+		data.mods = mods;
+		if ((error = git_config_foreach(
+			    mods, submodule_load_each, &data)) < 0)
+			goto cleanup;
+	}
 	/* add back submodule information from index */
 	if (idx) {
-		if ((error = submodules_from_index(map, idx)) < 0)
+		if ((error = submodules_from_index(map, idx, mods)) < 0)
 			goto cleanup;
 	}
 	/* add submodule information from HEAD */
 	if (head) {
-		if ((error = submodules_from_head(map, head)) < 0)
-			goto cleanup;
-	}
-	/* add submodule information from .gitmodules */
-	if (wd) {
-		lfc_data data = { 0 };
-		data.map = map;
-		data.repo = repo;
-		if ((mods = open_gitmodules(repo, false)) != NULL &&
-		    (error = git_config_file_foreach(
-			    mods, submodule_load_from_config, &data)) < 0)
+		if ((error = submodules_from_head(map, head, mods)) < 0)
 			goto cleanup;
 	}
 	/* shallow scan submodules in work tree as needed */
@@ -428,7 +482,7 @@ static int all_submodules(git_repository *repo, git_strmap *map)
 	}
 
 cleanup:
-	git_config_file_free(mods);
+	git_config_free(mods);
 	/* TODO: if we got an error, mark submodule config as invalid? */
 	git_index_free(idx);
 	git_tree_free(head);
@@ -1370,8 +1424,7 @@ static int submodule_update_head(git_submodule *submodule)
 int git_submodule_reload(git_submodule *sm, int force)
 {
 	int error = 0;
-	git_config_backend *mods;
-	lfc_data data = { 0 };
+	git_config *mods;
 
 	GIT_UNUSED(force);
 
@@ -1390,28 +1443,14 @@ int git_submodule_reload(git_submodule *sm, int force)
 		return error;
 
 	/* refresh config data */
-	mods = open_gitmodules(sm->repo, GITMODULES_EXISTING);
+	mods = gitmodules_snapshot(sm->repo);
 	if (mods != NULL) {
-		git_buf path = GIT_BUF_INIT;
-
-		git_buf_sets(&path, "submodule\\.");
-		git_buf_text_puts_escape_regex(&path, sm->name);
-		git_buf_puts(&path, "\\..*");
-
-		if (git_buf_oom(&path)) {
-			error = -1;
-		} else {
-			data.have_sm = 1;
-			data.sm = sm;
-			error = git_config_file_foreach_match(
-				mods, path.ptr, submodule_load_from_config, &data);
-		}
+		error = submodule_read_config(sm, mods);
+		git_config_free(mods);
 
-		git_buf_free(&path);
-		git_config_file_free(mods);
-
-		if (error < 0)
+		if (error < 0) {
 			return error;
+		}
 	}
 
 	/* refresh wd data */
@@ -1627,134 +1666,141 @@ int git_submodule_parse_recurse(git_submodule_recurse_t *out, const char *value)
 	return 0;
 }
 
-static int submodule_load_from_config(
-	const git_config_entry *entry, void *payload)
+static int get_value(const char **out, git_config *cfg, git_buf *buf, const char *name, const char *field)
 {
-	const char *namestart, *property;
-	const char *key = entry->name, *value = entry->value, *path;
-	char *alternate = NULL, *replaced = NULL;
-	git_buf name = GIT_BUF_INIT;
-	lfc_data *data = payload;
-	git_submodule *sm;
-	int error = 0;
-
-	if (git__prefixcmp(key, "submodule.") != 0)
-		return 0;
-
-	namestart = key + strlen("submodule.");
-	property  = strrchr(namestart, '.');
-
-	if (!property || (property == namestart))
-		return 0;
-
-	property++;
-	path = !strcasecmp(property, "path") ? value : NULL;
+	int error;
 
-	if ((error = git_buf_set(&name, namestart, property - namestart -1)) < 0)
-		goto done;
+	git_buf_clear(buf);
 
-	if (data->have_sm) {
-		sm = data->sm;
-	} else {
-		khiter_t pos;
-		git_strmap *map = data->map;
-		pos = git_strmap_lookup_index(map, path ? path : name.ptr);
-		if (git_strmap_valid_index(map, pos)) {
-			sm = git_strmap_value_at(map, pos);
-		} else {
-			if ((error = submodule_alloc(&sm, data->repo, name.ptr)) < 0)
-				goto done;
+	if ((error = git_buf_printf(buf, "submodule.%s.%s", name, field)) < 0 ||
+	    (error = git_config_get_string(out, cfg, buf->ptr)) < 0)
+		return error;
 
-			git_strmap_insert(map, sm->name, sm, error);
-			assert(error != 0);
-			if (error < 0)
-				goto done;
-			error = 0;
-		}
-	}
+	return error;
+}
 
-	sm->flags |= GIT_SUBMODULE_STATUS_IN_CONFIG;
+static int submodule_read_config(git_submodule *sm, git_config *cfg)
+{
+	git_buf key = GIT_BUF_INIT;
+	const char *value;
+	int error, in_config = 0;
 
-	/* Only from config might we get differing names & paths.  If so, then
-	 * update the submodule and insert under the alternative key.
+	/*
+	 * TODO: Look up path in index and if it is present but not a GITLINK
+	 * then this should be deleted (at least to match git's behavior)
 	 */
 
-	/* TODO: if case insensitive filesystem, then the following strcmps
+	if ((error = get_value(&value, cfg, &key, sm->name, "path")) == 0) {
+		in_config = 1;
+	/*
+	 * TODO: if case insensitive filesystem, then the following strcmp
 	 * should be strcasecmp
 	 */
-
-	if (strcmp(sm->name, name.ptr) != 0) { /* name changed */
-		if (sm->path && !strcmp(sm->path, name.ptr)) { /* already set as path */
-			replaced = sm->name;
-			sm->name = sm->path;
-		} else {
-			if (sm->name != sm->path)
-				replaced = sm->name;
-			alternate = sm->name = git_buf_detach(&name);
-		}
-	}
-	else if (path && strcmp(path, sm->path) != 0) { /* path changed */
-		if (!strcmp(sm->name, value)) { /* already set as name */
-			replaced = sm->path;
-			sm->path = sm->name;
-		} else {
-			if (sm->path != sm->name)
-				replaced = sm->path;
-			if ((alternate = git__strdup(value)) == NULL) {
-				error = -1;
-				goto done;
-			}
-			sm->path = alternate;
+		if (strcmp(sm->name, value) != 0) {
+			sm->path = git__strdup(value);
+			GITERR_CHECK_ALLOC(sm->path);
 		}
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
 
-	/* Deregister under name being replaced */
-	if (replaced) {
-		git__free(replaced);
+	if ((error = get_value(&value, cfg, &key, sm->name, "url")) == 0) {
+		in_config = 1;
+		sm->url = git__strdup(value);
+		GITERR_CHECK_ALLOC(sm->url);
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
 
-	/* TODO: Look up path in index and if it is present but not a GITLINK
-	 * then this should be deleted (at least to match git's behavior)
-	 */
-
-	if (path)
-		goto done;
-
-	/* copy other properties into submodule entry */
-	if (strcasecmp(property, "url") == 0) {
-		git__free(sm->url);
-		sm->url = NULL;
-
-		if (value != NULL && (sm->url = git__strdup(value)) == NULL) {
-			error = -1;
-			goto done;
-		}
+	if ((error = get_value(&value, cfg, &key, sm->name, "branch")) == 0) {
+		in_config = 1;
+		sm->branch = git__strdup(value);
+		GITERR_CHECK_ALLOC(sm->branch);
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
-	else if (strcasecmp(property, "branch") == 0) {
-		git__free(sm->branch);
-		sm->branch = NULL;
 
-		if (value != NULL && (sm->branch = git__strdup(value)) == NULL) {
-			error = -1;
-			goto done;
-		}
-	}
-	else if (strcasecmp(property, "update") == 0) {
+	if ((error = get_value(&value, cfg, &key, sm->name, "update")) == 0) {
+		in_config = 1;
 		if ((error = git_submodule_parse_update(&sm->update, value)) < 0)
-			goto done;
+			return error;
 		sm->update_default = sm->update;
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
-	else if (strcasecmp(property, "fetchRecurseSubmodules") == 0) {
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "fetchRecurseSubmodules")) == 0) {
+		in_config = 1;
 		if ((error = git_submodule_parse_recurse(&sm->fetch_recurse, value)) < 0)
-			goto done;
+			return error;
 		sm->fetch_recurse_default = sm->fetch_recurse;
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
-	else if (strcasecmp(property, "ignore") == 0) {
+
+	if ((error = get_value(&value, cfg, &key, sm->name, "ignore")) == 0) {
+		in_config = 1;
 		if ((error = git_submodule_parse_ignore(&sm->ignore, value)) < 0)
-			goto done;
+			return error;
 		sm->ignore_default = sm->ignore;
+	} else if (error != GIT_ENOTFOUND) {
+		return error;
 	}
-	/* ignore other unknown submodule properties */
+
+	if (in_config)
+		sm->flags |= GIT_SUBMODULE_STATUS_IN_CONFIG;
+
+	return 0;
+}
+
+static int submodule_load_each(const git_config_entry *entry, void *payload)
+{
+	lfc_data *data = payload;
+	const char *namestart, *property;
+	git_strmap_iter pos;
+	git_strmap *map = data->map;
+	git_buf name = GIT_BUF_INIT;
+	git_submodule *sm;
+	int error;
+
+	if (git__prefixcmp(entry->name, "submodule.") != 0)
+		return 0;
+
+	namestart = entry->name + strlen("submodule.");
+	property  = strrchr(namestart, '.');
+
+	if (!property || (property == namestart))
+		return 0;
+
+	property++;
+
+	if ((error = git_buf_set(&name, namestart, property - namestart -1)) < 0)
+		return error;
+
+	/*
+	 * Now that we have the submodule's name, we can use that to
+	 * figure out whether it's in the map. If it's not, we create
+	 * a new submodule, load the config and insert it. If it's
+	 * already inserted, we've already loaded it, so we skip.
+	 */
+	pos = git_strmap_lookup_index(map, name.ptr);
+	if (git_strmap_valid_index(map, pos))
+		return 0;
+
+	if ((error = submodule_alloc(&sm, data->repo, name.ptr)) < 0)
+		goto done;
+
+	if ((error = submodule_read_config(sm, data->mods)) < 0) {
+		git_submodule_free(sm);
+		goto done;
+	}
+
+	git_strmap_insert(map, sm->name, sm, error);
+	assert(error != 0);
+	if (error < 0)
+		goto done;
+
+	error = 0;
 
 done:
 	git_buf_free(&name);
@@ -1778,6 +1824,35 @@ static int submodule_load_from_wd_lite(git_submodule *sm)
 	return 0;
 }
 
+/**
+ * Returns a snapshot of $WORK_TREE/.gitmodules.
+ *
+ * We ignore any errors and just pretend the file isn't there.
+ */
+static git_config *gitmodules_snapshot(git_repository *repo)
+{
+	const char *workdir = git_repository_workdir(repo);
+	git_config *mods = NULL, *snap = NULL;
+	git_buf path = GIT_BUF_INIT;
+
+	if (workdir != NULL) {
+		if (git_buf_joinpath(&path, workdir, GIT_MODULES_FILE) != 0)
+			return NULL;
+
+		if (git_config_open_ondisk(&mods, path.ptr) < 0)
+			mods = NULL;
+	}
+
+	git_buf_free(&path);
+
+	if (mods) {
+		git_config_snapshot(&snap, mods);
+		git_config_free(mods);
+	}
+
+	return snap;
+}
+
 static git_config_backend *open_gitmodules(
 	git_repository *repo,
 	int okay_to_create)