Merge pull request #6756 from libgit2/ethomson/worktree-config

Separate config reader and writer backend priorities (for worktree configs)

include/git2/config.h

@@ -22,8 +22,19 @@ GIT_BEGIN_DECL
 
 /**
  * Priority level of a config file.
+ *
  * These priority levels correspond to the natural escalation logic
- * (from higher to lower) when searching for config entries in git.git.
+ * (from higher to lower) when reading or searching for config entries
+ * in git.git. Meaning that for the same key, the configuration in
+ * the local configuration is preferred over the configuration in
+ * the system configuration file.
+ *
+ * Callers can add their own custom configuration, beginning at the
+ * `GIT_CONFIG_LEVEL_APP` level.
+ *
+ * Writes, by default, occur in the highest priority level backend
+ * that is writable. This ordering can be overridden with
+ * `git_config_set_writeorder`.
  *
  * git_config_open_default() and git_repository_config() honor those
  * priority levels as well.
@@ -48,9 +59,13 @@ typedef enum {
 	 */
 	GIT_CONFIG_LEVEL_LOCAL = 5,
 
+	/** Worktree specific configuration file; $GIT_DIR/config.worktree
+	 */
+	GIT_CONFIG_LEVEL_WORKTREE = 6,
+
 	/** Application specific configuration file; freely defined by applications
 	 */
-	GIT_CONFIG_LEVEL_APP = 6,
+	GIT_CONFIG_LEVEL_APP = 7,
 
 	/** Represents the highest level available config file (i.e. the most
 	 * specific config file available that actually is loaded)
@@ -296,6 +311,11 @@ GIT_EXTERN(int) git_config_open_level(
  */
 GIT_EXTERN(int) git_config_open_global(git_config **out, git_config *config);
 
+GIT_EXTERN(int) git_config_set_writeorder(
+	git_config *cfg,
+	git_config_level_t *levels,
+	size_t len);
+
 /**
  * Create a snapshot of the configuration
  *

include/git2/errors.h

@@ -19,20 +19,20 @@ GIT_BEGIN_DECL
 
 /** Generic return codes */
 typedef enum {
-	GIT_OK         =  0,		/**< No error */
+	GIT_OK              =  0,		/**< No error */
 
-	GIT_ERROR      = -1,		/**< Generic error */
-	GIT_ENOTFOUND  = -3,		/**< Requested object could not be found */
-	GIT_EEXISTS    = -4,		/**< Object exists preventing operation */
-	GIT_EAMBIGUOUS = -5,		/**< More than one object matches */
-	GIT_EBUFS      = -6,		/**< Output buffer too short to hold data */
+	GIT_ERROR           = -1,		/**< Generic error */
+	GIT_ENOTFOUND       = -3,		/**< Requested object could not be found */
+	GIT_EEXISTS         = -4,		/**< Object exists preventing operation */
+	GIT_EAMBIGUOUS      = -5,		/**< More than one object matches */
+	GIT_EBUFS           = -6,		/**< Output buffer too short to hold data */
 
 	/**
 	 * GIT_EUSER is a special error that is never generated by libgit2
 	 * code.  You can return it from a callback (e.g to stop an iteration)
 	 * to know that it was generated by the callback and not by libgit2.
 	 */
-	GIT_EUSER      = -7,
+	GIT_EUSER           = -7,
 
 	GIT_EBAREREPO       =  -8,	/**< Operation not allowed on bare repository */
 	GIT_EUNBORNBRANCH   =  -9,	/**< HEAD refers to branch with no commits */
@@ -61,7 +61,8 @@ typedef enum {
 	GIT_EOWNER          = -36,	/**< The object is not owned by the current user */
 	GIT_TIMEOUT         = -37,	/**< The operation timed out */
 	GIT_EUNCHANGED      = -38,	/**< There were no changes */
-	GIT_ENOTSUPPORTED   = -39	/**< An option is not supported */
+	GIT_ENOTSUPPORTED   = -39,	/**< An option is not supported */
+	GIT_EREADONLY       = -40	/**< The subject is read-only */
 } git_error_code;
 
 /**

include/git2/repository.h

@@ -499,6 +499,7 @@ typedef enum {
 	GIT_REPOSITORY_ITEM_PACKED_REFS,
 	GIT_REPOSITORY_ITEM_REMOTES,
 	GIT_REPOSITORY_ITEM_CONFIG,
+	GIT_REPOSITORY_ITEM_WORKTREE_CONFIG,
 	GIT_REPOSITORY_ITEM_INFO,
 	GIT_REPOSITORY_ITEM_HOOKS,
 	GIT_REPOSITORY_ITEM_LOGS,

src/libgit2/config.h

@@ -24,7 +24,8 @@
 
 struct git_config {
 	git_refcount rc;
-	git_vector backends;
+	git_vector readers;
+	git_vector writers;
 };
 
 extern int git_config__global_location(git_str *buf);
@@ -94,17 +95,21 @@ int git_config_lookup_map_enum(git_configmap_t *type_out,
 	size_t map_n, int enum_val);
 
 /**
- * Unlock the backend with the highest priority
+ * Unlock the given backend that was previously locked.
  *
  * Unlocking will allow other writers to update the configuration
  * file. Optionally, any changes performed since the lock will be
  * applied to the configuration.
  *
- * @param cfg the configuration
+ * @param config the config instance
+ * @param data the config data passed to git_transaction_new
  * @param commit boolean which indicates whether to commit any changes
  * done since locking
  * @return 0 or an error code
  */
-GIT_EXTERN(int) git_config_unlock(git_config *cfg, int commit);
+GIT_EXTERN(int) git_config_unlock(
+	git_config *config,
+	void *data,
+	int commit);
 
 #endif

src/libgit2/repository.c

@@ -58,6 +58,7 @@ static const struct {
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "packed-refs", false },
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "remotes", true },
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "config", false },
+	{ GIT_REPOSITORY_ITEM_GITDIR, GIT_REPOSITORY_ITEM_GITDIR, "config.worktree", false },
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "info", true },
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "hooks", true },
 	{ GIT_REPOSITORY_ITEM_COMMONDIR, GIT_REPOSITORY_ITEM_GITDIR, "logs", true },
@@ -1273,6 +1274,24 @@ int git_repository_discover(
 	return error;
 }
 
+static int has_config_worktree(bool *out, git_config *cfg)
+{
+	int worktreeconfig = 0, error;
+
+	*out = false;
+
+	error = git_config_get_bool(&worktreeconfig, cfg, "extensions.worktreeconfig");
+
+	if (error == 0)
+		*out = worktreeconfig;
+	else if (error == GIT_ENOTFOUND)
+		*out = false;
+	else
+		return error;
+
+	return 0;
+}
+
 static int load_config(
 	git_config **out,
 	git_repository *repo,
@@ -1281,9 +1300,11 @@ static int load_config(
 	const char *system_config_path,
 	const char *programdata_path)
 {
-	int error;
 	git_str config_path = GIT_STR_INIT;
 	git_config *cfg = NULL;
+	git_config_level_t write_order;
+	bool has_worktree;
+	int error;
 
 	GIT_ASSERT_ARG(out);
 
@@ -1297,6 +1318,14 @@ static int load_config(
 		if (error && error != GIT_ENOTFOUND)
 			goto on_error;
 
+		if ((error = has_config_worktree(&has_worktree, cfg)) == 0 &&
+		    has_worktree &&
+		    (error = git_repository__item_path(&config_path, repo, GIT_REPOSITORY_ITEM_WORKTREE_CONFIG)) == 0)
+			error = git_config_add_file_ondisk(cfg, config_path.ptr, GIT_CONFIG_LEVEL_WORKTREE, repo, 0);
+
+		if (error && error != GIT_ENOTFOUND)
+			goto on_error;
+
 		git_str_dispose(&config_path);
 	}
 
@@ -1326,6 +1355,11 @@ static int load_config(
 
 	git_error_clear(); /* clear any lingering ENOTFOUND errors */
 
+	write_order = GIT_CONFIG_LEVEL_LOCAL;
+
+	if ((error = git_config_set_writeorder(cfg, &write_order, 1)) < 0)
+		goto on_error;
+
 	*out = cfg;
 	return 0;
 
@@ -1845,7 +1879,8 @@ static int check_repositoryformatversion(int *version, git_config *config)
 
 static const char *builtin_extensions[] = {
 	"noop",
-	"objectformat"
+	"objectformat",
+	"worktreeconfig",
 };
 
 static git_vector user_extensions = { 0, git__strcmp_cb };

src/libgit2/transaction.c

@@ -49,12 +49,16 @@ struct git_transaction {
 	git_repository *repo;
 	git_refdb *db;
 	git_config *cfg;
+	void *cfg_data;
 
 	git_strmap *locks;
 	git_pool pool;
 };
 
-int git_transaction_config_new(git_transaction **out, git_config *cfg)
+int git_transaction_config_new(
+	git_transaction **out,
+	git_config *cfg,
+	void *data)
 {
 	git_transaction *tx;
 
@@ -66,6 +70,8 @@ int git_transaction_config_new(git_transaction **out, git_config *cfg)
 
 	tx->type = TRANSACTION_CONFIG;
 	tx->cfg = cfg;
+	tx->cfg_data = data;
+
 	*out = tx;
 	return 0;
 }
@@ -333,8 +339,9 @@ int git_transaction_commit(git_transaction *tx)
 	GIT_ASSERT_ARG(tx);
 
 	if (tx->type == TRANSACTION_CONFIG) {
-		error = git_config_unlock(tx->cfg, true);
+		error = git_config_unlock(tx->cfg, tx->cfg_data, true);
 		tx->cfg = NULL;
+		tx->cfg_data = NULL;
 
 		return error;
 	}
@@ -369,10 +376,8 @@ void git_transaction_free(git_transaction *tx)
 		return;
 
 	if (tx->type == TRANSACTION_CONFIG) {
-		if (tx->cfg) {
-			git_config_unlock(tx->cfg, false);
-			git_config_free(tx->cfg);
-		}
+		if (tx->cfg)
+			git_config_unlock(tx->cfg, tx->cfg_data, false);
 
 		git__free(tx);
 		return;

src/libgit2/transaction.h

@@ -9,6 +9,9 @@
 
 #include "common.h"
 
-int git_transaction_config_new(git_transaction **out, git_config *cfg);
+int git_transaction_config_new(
+	git_transaction **out,
+	git_config *cfg,
+	void *data);
 
 #endif

tests/libgit2/config/configlevel.c

@@ -71,3 +71,21 @@ void test_config_configlevel__fetching_a_level_from_an_empty_compound_config_ret
 
 	git_config_free(cfg);
 }
+
+void test_config_configlevel__can_override_local_with_worktree(void)
+{
+	git_config *cfg;
+	git_buf buf = GIT_BUF_INIT;
+
+	cl_git_pass(git_config_new(&cfg));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config19"),
+		GIT_CONFIG_LEVEL_WORKTREE, NULL, 1));
+	cl_git_pass(git_config_add_file_ondisk(cfg, cl_fixture("config/config18"),
+		GIT_CONFIG_LEVEL_LOCAL, NULL, 1));
+
+	cl_git_pass(git_config_get_string_buf(&buf, cfg, "core.stringglobal"));
+	cl_assert_equal_s("don't find me!", buf.ptr);
+
+	git_buf_dispose(&buf);
+	git_config_free(cfg);
+}

tests/libgit2/config/readonly.c

@@ -24,7 +24,7 @@ void test_config_readonly__writing_to_readonly_fails(void)
 	backend->readonly = 1;
 	cl_git_pass(git_config_add_backend(cfg, backend, GIT_CONFIG_LEVEL_GLOBAL, NULL, 0));
 
-	cl_git_fail_with(GIT_ENOTFOUND, git_config_set_string(cfg, "foo.bar", "baz"));
+	cl_git_fail_with(GIT_EREADONLY, git_config_set_string(cfg, "foo.bar", "baz"));
 	cl_assert(!git_fs_path_exists("global"));
 }
 

tests/libgit2/config/write.c

@@ -696,6 +696,36 @@ void test_config_write__locking(void)
 	git_config_free(cfg);
 }
 
+void test_config_write__abort_lock(void)
+{
+	git_config *cfg;
+	git_config_entry *entry;
+	git_transaction *tx;
+	const char *filename = "locked-file";
+
+	/* Open the config and lock it */
+	cl_git_mkfile(filename, "[section]\n\tname = value\n");
+	cl_git_pass(git_config_open_ondisk(&cfg, filename));
+	cl_git_pass(git_config_get_entry(&entry, cfg, "section.name"));
+	cl_assert_equal_s("value", entry->value);
+	git_config_entry_free(entry);
+	cl_git_pass(git_config_lock(&tx, cfg));
+
+	/* Change entries in the locked backend */
+	cl_git_pass(git_config_set_string(cfg, "section.name", "other value"));
+	cl_git_pass(git_config_set_string(cfg, "section2.name3", "more value"));
+
+	git_transaction_free(tx);
+
+	/* Now that we've unlocked it, we should see no changes */
+	cl_git_pass(git_config_get_entry(&entry, cfg, "section.name"));
+	cl_assert_equal_s("value", entry->value);
+	git_config_entry_free(entry);
+	cl_git_fail_with(GIT_ENOTFOUND, git_config_get_entry(&entry, cfg, "section2.name3"));
+
+	git_config_free(cfg);
+}
+
 void test_config_write__repeated(void)
 {
 	const char *filename = "config-repeated";

tests/libgit2/core/opts.c

@@ -34,9 +34,10 @@ void test_core_opts__extensions_query(void)
 
 	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_EXTENSIONS, &out));
 
-	cl_assert_equal_sz(out.count, 2);
+	cl_assert_equal_sz(out.count, 3);
 	cl_assert_equal_s("noop", out.strings[0]);
 	cl_assert_equal_s("objectformat", out.strings[1]);
+	cl_assert_equal_s("worktreeconfig", out.strings[2]);
 
 	git_strarray_dispose(&out);
 }
@@ -49,10 +50,11 @@ void test_core_opts__extensions_add(void)
 	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, in, ARRAY_SIZE(in)));
 	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_EXTENSIONS, &out));
 
-	cl_assert_equal_sz(out.count, 3);
+	cl_assert_equal_sz(out.count, 4);
 	cl_assert_equal_s("foo", out.strings[0]);
 	cl_assert_equal_s("noop", out.strings[1]);
 	cl_assert_equal_s("objectformat", out.strings[2]);
+	cl_assert_equal_s("worktreeconfig", out.strings[3]);
 
 	git_strarray_dispose(&out);
 }
@@ -65,10 +67,11 @@ void test_core_opts__extensions_remove(void)
 	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, in, ARRAY_SIZE(in)));
 	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_EXTENSIONS, &out));
 
-	cl_assert_equal_sz(out.count, 3);
+	cl_assert_equal_sz(out.count, 4);
 	cl_assert_equal_s("bar", out.strings[0]);
 	cl_assert_equal_s("baz", out.strings[1]);
 	cl_assert_equal_s("objectformat", out.strings[2]);
+	cl_assert_equal_s("worktreeconfig", out.strings[3]);
 
 	git_strarray_dispose(&out);
 }
@@ -81,11 +84,12 @@ void test_core_opts__extensions_uniq(void)
 	cl_git_pass(git_libgit2_opts(GIT_OPT_SET_EXTENSIONS, in, ARRAY_SIZE(in)));
 	cl_git_pass(git_libgit2_opts(GIT_OPT_GET_EXTENSIONS, &out));
 
-	cl_assert_equal_sz(out.count, 4);
+	cl_assert_equal_sz(out.count, 5);
 	cl_assert_equal_s("bar", out.strings[0]);
 	cl_assert_equal_s("foo", out.strings[1]);
 	cl_assert_equal_s("noop", out.strings[2]);
 	cl_assert_equal_s("objectformat", out.strings[3]);
+	cl_assert_equal_s("worktreeconfig", out.strings[4]);
 
 	git_strarray_dispose(&out);
 }

tests/libgit2/worktree/config.c

@@ -6,15 +6,19 @@
 
 static worktree_fixture fixture =
 	WORKTREE_FIXTURE_INIT(COMMON_REPO, WORKTREE_REPO);
+static worktree_fixture submodule =
+	WORKTREE_FIXTURE_INIT("submodules", "submodules-worktree-parent");
 
 void test_worktree_config__initialize(void)
 {
 	setup_fixture_worktree(&fixture);
+	setup_fixture_worktree(&submodule);
 }
 
 void test_worktree_config__cleanup(void)
 {
 	cleanup_fixture_worktree(&fixture);
+	cleanup_fixture_worktree(&submodule);
 }
 
 void test_worktree_config__open(void)
@@ -27,7 +31,7 @@ void test_worktree_config__open(void)
 	git_config_free(cfg);
 }
 
-void test_worktree_config__set(void)
+void test_worktree_config__set_level_local(void)
 {
 	git_config *cfg;
 	int32_t val;
@@ -45,3 +49,78 @@ void test_worktree_config__set(void)
 	cl_assert_equal_i(val, 5);
 	git_config_free(cfg);
 }
+
+void test_worktree_config__requires_extension(void)
+{
+	git_config *cfg;
+	git_config *wtcfg;
+	int extension = 0;
+
+	/*
+	 * the "submodules" repo does not have extensions.worktreeconfig
+	 * set, the worktree configuration should not be available.
+	 */
+	cl_git_pass(git_repository_config(&cfg, submodule.repo));
+	cl_git_fail_with(GIT_ENOTFOUND, git_config_get_bool(&extension, cfg, "extensions.worktreeconfig"));
+	cl_assert_equal_i(0, extension);
+	cl_git_fail_with(GIT_ENOTFOUND, git_config_open_level(&wtcfg, cfg, GIT_CONFIG_LEVEL_WORKTREE));
+	git_config_free(cfg);
+
+	/* the "testrepo" repo does have the configuration set. */
+	cl_git_pass(git_repository_config(&cfg, fixture.repo));
+	cl_git_pass(git_config_get_bool(&extension, cfg, "extensions.worktreeconfig"));
+	cl_assert_equal_i(1, extension);
+	cl_git_pass(git_config_open_level(&wtcfg, cfg, GIT_CONFIG_LEVEL_WORKTREE));
+	git_config_free(wtcfg);
+	git_config_free(cfg);
+}
+
+void test_worktree_config__exists(void)
+{
+	git_config *cfg, *wtcfg, *snap;
+	const char *str;
+
+	cl_git_pass(git_repository_config(&cfg, fixture.repo));
+	cl_git_pass(git_repository_config(&wtcfg, fixture.worktree));
+
+	cl_git_pass(git_config_snapshot(&snap, cfg));
+	cl_git_pass(git_config_get_string(&str, snap, "worktreetest.config"));
+	cl_assert_equal_s("mainrepo", str);
+	git_config_free(snap);
+
+	cl_git_pass(git_config_snapshot(&snap, wtcfg));
+	cl_git_pass(git_config_get_string(&str, snap, "worktreetest.config"));
+	cl_assert_equal_s("worktreerepo", str);
+	git_config_free(snap);
+
+	git_config_free(cfg);
+	git_config_free(wtcfg);
+}
+
+void test_worktree_config__set_level_worktree(void)
+{
+	git_config *cfg;
+	git_config *wtcfg;
+	int32_t val;
+
+	cl_git_pass(git_repository_config(&cfg, fixture.repo));
+	cl_git_pass(git_config_open_level(&wtcfg, cfg, GIT_CONFIG_LEVEL_WORKTREE));
+	cl_git_pass(git_config_set_int32(wtcfg, "worktree.specific", 42));
+
+	cl_git_pass(git_config_get_int32(&val, cfg, "worktree.specific"));
+	cl_assert_equal_i(val, 42);
+
+	/* reopen to verify config has been set */
+	git_config_free(cfg);
+	cl_git_pass(git_repository_config(&cfg, fixture.repo));
+	cl_git_pass(git_config_get_int32(&val, cfg, "worktree.specific"));
+	cl_assert_equal_i(val, 42);
+
+	cl_git_fail_with(GIT_ENOTFOUND, git_config_delete_entry(cfg, "worktree.specific"));
+
+	cl_git_pass(git_config_delete_entry(wtcfg, "worktree.specific"));
+	cl_git_fail_with(GIT_ENOTFOUND, git_config_get_int32(&val, cfg, "worktree.specific"));
+
+	git_config_free(cfg);
+	git_config_free(wtcfg);
+}

tests/resources/testrepo/.gitted/config

@@ -3,6 +3,8 @@
         filemode = true
         bare = false
         logallrefupdates = true
+[extensions]
+	worktreeconfig = true
 [remote "test"]
 	url = git://github.com/libgit2/libgit2
 	fetch = +refs/heads/*:refs/remotes/test/*

tests/resources/testrepo/.gitted/config.worktree

@@ -0,0 +1,2 @@
+[worktreetest]
+	config = mainrepo

tests/resources/testrepo/.gitted/worktrees/testrepo-worktree/config.worktree

@@ -0,0 +1,2 @@
+[worktreetest]
+	config = worktreerepo