Merge branch 'hv/config-from-blob'

Allow configuration data to be read from in-tree blob objects,
which would help working in a bare repository and submodule
updates.

* hv/config-from-blob:
  do not die when error in config parsing of buf occurs
  teach config --blob option to parse config from database
  config: make parsing stack struct independent from actual data source
  config: drop cf validity check in get_next_char()
  config: factor out config file stack management

Author: gitster

Documentation/git-config.txt

@@ -127,6 +127,13 @@ See also <<FILES>>.
 --file config-file::
 	Use the given config file instead of the one specified by GIT_CONFIG.
 
+--blob blob::
+	Similar to '--file' but use the given blob instead of a file. E.g.
+	you can use 'master:.gitmodules' to read values from the file
+	'.gitmodules' in the master branch. See "SPECIFYING REVISIONS"
+	section in linkgit:gitrevisions[7] for a more complete list of
+	ways to spell blob names.
+
 --remove-section::
 	Remove the given section from the configuration file.
 

builtin/config.c

@@ -21,6 +21,7 @@ static char term = '\n';
 
 static int use_global_config, use_system_config, use_local_config;
 static const char *given_config_file;
+static const char *given_config_blob;
 static int actions, types;
 static const char *get_color_slot, *get_colorbool_slot;
 static int end_null;
@@ -53,6 +54,7 @@ static struct option builtin_config_options[] = {
 	OPT_BOOLEAN(0, "system", &use_system_config, N_("use system config file")),
 	OPT_BOOLEAN(0, "local", &use_local_config, N_("use repository config file")),
 	OPT_STRING('f', "file", &given_config_file, N_("file"), N_("use given config file")),
+	OPT_STRING(0, "blob", &given_config_blob, N_("blob-id"), N_("read config from given blob object")),
 	OPT_GROUP(N_("Action")),
 	OPT_BIT(0, "get", &actions, N_("get value: name [value-regex]"), ACTION_GET),
 	OPT_BIT(0, "get-all", &actions, N_("get all values: key [value-regex]"), ACTION_GET_ALL),
@@ -218,7 +220,8 @@ static int get_value(const char *key_, const char *regex_)
 	}
 
 	git_config_with_options(collect_config, &values,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	ret = !values.nr;
 
@@ -302,7 +305,8 @@ static void get_color(const char *def_color)
 	get_color_found = 0;
 	parsed_color[0] = '\0';
 	git_config_with_options(git_get_color_config, NULL,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	if (!get_color_found && def_color)
 		color_parse(def_color, "command line", parsed_color);
@@ -331,7 +335,8 @@ static int get_colorbool(int print)
 	get_diff_color_found = -1;
 	get_color_ui_found = -1;
 	git_config_with_options(git_get_colorbool_config, NULL,
-				given_config_file, respect_includes);
+				given_config_file, given_config_blob,
+				respect_includes);
 
 	if (get_colorbool_found < 0) {
 		if (!strcmp(get_colorbool_slot, "color.diff"))
@@ -353,6 +358,12 @@ static int get_colorbool(int print)
 		return get_colorbool_found ? 0 : 1;
 }
 
+static void check_blob_write(void)
+{
+	if (given_config_blob)
+		die("writing config blobs is not supported");
+}
+
 int cmd_config(int argc, const char **argv, const char *prefix)
 {
 	int nongit = !startup_info->have_repository;
@@ -364,7 +375,8 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 			     builtin_config_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 
-	if (use_global_config + use_system_config + use_local_config + !!given_config_file > 1) {
+	if (use_global_config + use_system_config + use_local_config +
+	    !!given_config_file + !!given_config_blob > 1) {
 		error("only one config file at a time.");
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
@@ -443,6 +455,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		check_argc(argc, 0, 0);
 		if (git_config_with_options(show_all_config, NULL,
 					    given_config_file,
+					    given_config_blob,
 					    respect_includes) < 0) {
 			if (given_config_file)
 				die_errno("unable to read config file '%s'",
@@ -455,13 +468,16 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		check_argc(argc, 0, 0);
 		if (!given_config_file && nongit)
 			die("not in a git directory");
+		if (given_config_blob)
+			die("editing blobs is not supported");
 		git_config(git_default_config, NULL);
 		launch_editor(given_config_file ?
 			      given_config_file : git_path("config"),
 			      NULL, NULL);
 	}
 	else if (actions == ACTION_SET) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		value = normalize_value(argv[0], argv[1]);
 		ret = git_config_set_in_file(given_config_file, argv[0], value);
@@ -471,18 +487,21 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		return ret;
 	}
 	else if (actions == ACTION_SET_ALL) {
+		check_blob_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], value, argv[2], 0);
 	}
 	else if (actions == ACTION_ADD) {
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], value, "^$", 0);
 	}
 	else if (actions == ACTION_REPLACE_ALL) {
+		check_blob_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
 		return git_config_set_multivar_in_file(given_config_file,
@@ -505,6 +524,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		return get_value(argv[0], argv[1]);
 	}
 	else if (actions == ACTION_UNSET) {
+		check_blob_write();
 		check_argc(argc, 1, 2);
 		if (argc == 2)
 			return git_config_set_multivar_in_file(given_config_file,
@@ -514,12 +534,14 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 						      argv[0], NULL);
 	}
 	else if (actions == ACTION_UNSET_ALL) {
+		check_blob_write();
 		check_argc(argc, 1, 2);
 		return git_config_set_multivar_in_file(given_config_file,
 						       argv[0], NULL, argv[1], 1);
 	}
 	else if (actions == ACTION_RENAME_SECTION) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 2, 2);
 		ret = git_config_rename_section_in_file(given_config_file,
 							argv[0], argv[1]);
@@ -530,6 +552,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_REMOVE_SECTION) {
 		int ret;
+		check_blob_write();
 		check_argc(argc, 1, 1);
 		ret = git_config_rename_section_in_file(given_config_file,
 							argv[0], NULL);

cache.h

@@ -1176,11 +1176,15 @@ extern int update_server_info(int);
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int git_default_config(const char *, const char *, void *);
 extern int git_config_from_file(config_fn_t fn, const char *, void *);
+extern int git_config_from_buf(config_fn_t fn, const char *name,
+			       const char *buf, size_t len, void *data);
 extern void git_config_push_parameter(const char *text);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern int git_config(config_fn_t fn, void *);
 extern int git_config_with_options(config_fn_t fn, void *,
-				   const char *filename, int respect_includes);
+				   const char *filename,
+				   const char *blob_ref,
+				   int respect_includes);
 extern int git_config_early(config_fn_t fn, void *, const char *repo_config);
 extern int git_parse_ulong(const char *, unsigned long *);
 extern int git_config_int(const char *, const char *);