thodg/libgit2

diff --git a/src/submodule.c b/src/submodule.c
index 7f52c36..1d73dc2 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)