Merge branch 'ks/config-file-stdin'

"git config" learned to read from the standard input when "-" is
given as the value to its "--file" parameter (attempting an
operation to update the configuration in the standard input of
course is rejected).

* ks/config-file-stdin:
  config: teach "git config --file -" to read from the standard input
  config: change git_config_with_options() interface
  builtin/config.c: rename check_blob_write() -> check_write()
  config: disallow relative include paths from blobs

5 files changed, 145 insertions, 77 deletions

diff --git a/builtin/config.c b/builtin/config.c
index 92ebf23f0a..5677c942b6 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -21,8 +21,7 @@ static char key_delim = ' ';
 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 struct git_config_source given_config_source;
 static int actions, types;
 static const char *get_color_slot, *get_colorbool_slot;
 static int end_null;
@@ -55,8 +54,8 @@ static struct option builtin_config_options[] = {
 	OPT_BOOL(0, "global", &use_global_config, N_("use global config file")),
 	OPT_BOOL(0, "system", &use_system_config, N_("use system config file")),
 	OPT_BOOL(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_STRING('f', "file", &given_config_source.file, N_("file"), N_("use given config file")),
+	OPT_STRING(0, "blob", &given_config_source.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),
@@ -224,8 +223,7 @@ static int get_value(const char *key_, const char *regex_)
 	}
 
 	git_config_with_options(collect_config, &values,
-				given_config_file, given_config_blob,
-				respect_includes);
+				&given_config_source, respect_includes);
 
 	ret = !values.nr;
 
@@ -309,8 +307,7 @@ 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, given_config_blob,
-				respect_includes);
+				&given_config_source, respect_includes);
 
 	if (!get_color_found && def_color)
 		color_parse(def_color, "command line", parsed_color);
@@ -339,8 +336,7 @@ 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, given_config_blob,
-				respect_includes);
+				&given_config_source, respect_includes);
 
 	if (get_colorbool_found < 0) {
 		if (!strcmp(get_colorbool_slot, "color.diff"))
@@ -362,9 +358,12 @@ static int get_colorbool(int print)
 		return get_colorbool_found ? 0 : 1;
 }
 
-static void check_blob_write(void)
+static void check_write(void)
 {
-	if (given_config_blob)
+	if (given_config_source.use_stdin)
+		die("writing to stdin is not supported");
+
+	if (given_config_source.blob)
 		die("writing config blobs is not supported");
 }
 
@@ -435,7 +434,7 @@ static int get_urlmatch(const char *var, const char *url)
 	}
 
 	git_config_with_options(urlmatch_config_entry, &config,
-				given_config_file, NULL, respect_includes);
+				&given_config_source, respect_includes);
 
 	for_each_string_list_item(item, &values) {
 		struct urlmatch_current_candidate_value *matched = item->util;
@@ -464,18 +463,24 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	int nongit = !startup_info->have_repository;
 	char *value;
 
-	given_config_file = getenv(CONFIG_ENVIRONMENT);
+	given_config_source.file = getenv(CONFIG_ENVIRONMENT);
 
 	argc = parse_options(argc, argv, prefix, builtin_config_options,
 			     builtin_config_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 
 	if (use_global_config + use_system_config + use_local_config +
-	    !!given_config_file + !!given_config_blob > 1) {
+	    !!given_config_source.file + !!given_config_source.blob > 1) {
 		error("only one config file at a time.");
 		usage_with_options(builtin_config_usage, builtin_config_options);
 	}
 
+	if (given_config_source.file &&
+			!strcmp(given_config_source.file, "-")) {
+		given_config_source.file = NULL;
+		given_config_source.use_stdin = 1;
+	}
+
 	if (use_global_config) {
 		char *user_config = NULL;
 		char *xdg_config = NULL;
@@ -493,24 +498,24 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 
 		if (access_or_warn(user_config, R_OK, 0) &&
 		    xdg_config && !access_or_warn(xdg_config, R_OK, 0))
-			given_config_file = xdg_config;
+			given_config_source.file = xdg_config;
 		else
-			given_config_file = user_config;
+			given_config_source.file = user_config;
 	}
 	else if (use_system_config)
-		given_config_file = git_etc_gitconfig();
+		given_config_source.file = git_etc_gitconfig();
 	else if (use_local_config)
-		given_config_file = git_pathdup("config");
-	else if (given_config_file) {
-		if (!is_absolute_path(given_config_file) && prefix)
-			given_config_file =
+		given_config_source.file = git_pathdup("config");
+	else if (given_config_source.file) {
+		if (!is_absolute_path(given_config_source.file) && prefix)
+			given_config_source.file =
 				xstrdup(prefix_filename(prefix,
 							strlen(prefix),
-							given_config_file));
+							given_config_source.file));
 	}
 
 	if (respect_includes == -1)
-		respect_includes = !given_config_file;
+		respect_includes = !given_config_source.file;
 
 	if (end_null) {
 		term = '\0';
@@ -549,57 +554,58 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	if (actions == ACTION_LIST) {
 		check_argc(argc, 0, 0);
 		if (git_config_with_options(show_all_config, NULL,
-					    given_config_file,
-					    given_config_blob,
+					    &given_config_source,
 					    respect_includes) < 0) {
-			if (given_config_file)
+			if (given_config_source.file)
 				die_errno("unable to read config file '%s'",
-					  given_config_file);
+					  given_config_source.file);
 			else
 				die("error processing config file(s)");
 		}
 	}
 	else if (actions == ACTION_EDIT) {
 		check_argc(argc, 0, 0);
-		if (!given_config_file && nongit)
+		if (!given_config_source.file && nongit)
 			die("not in a git directory");
-		if (given_config_blob)
+		if (given_config_source.use_stdin)
+			die("editing stdin is not supported");
+		if (given_config_source.blob)
 			die("editing blobs is not supported");
 		git_config(git_default_config, NULL);
-		launch_editor(given_config_file ?
-			      given_config_file : git_path("config"),
+		launch_editor(given_config_source.file ?
+			      given_config_source.file : git_path("config"),
 			      NULL, NULL);
 	}
 	else if (actions == ACTION_SET) {
 		int ret;
-		check_blob_write();
+		check_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);
+		ret = git_config_set_in_file(given_config_source.file, argv[0], value);
 		if (ret == CONFIG_NOTHING_SET)
 			error("cannot overwrite multiple values with a single value\n"
 			"       Use a regexp, --add or --replace-all to change %s.", argv[0]);
 		return ret;
 	}
 	else if (actions == ACTION_SET_ALL) {
-		check_blob_write();
+		check_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
-		return git_config_set_multivar_in_file(given_config_file,
+		return git_config_set_multivar_in_file(given_config_source.file,
 						       argv[0], value, argv[2], 0);
 	}
 	else if (actions == ACTION_ADD) {
-		check_blob_write();
+		check_write();
 		check_argc(argc, 2, 2);
 		value = normalize_value(argv[0], argv[1]);
-		return git_config_set_multivar_in_file(given_config_file,
+		return git_config_set_multivar_in_file(given_config_source.file,
 						       argv[0], value, "^$", 0);
 	}
 	else if (actions == ACTION_REPLACE_ALL) {
-		check_blob_write();
+		check_write();
 		check_argc(argc, 2, 3);
 		value = normalize_value(argv[0], argv[1]);
-		return git_config_set_multivar_in_file(given_config_file,
+		return git_config_set_multivar_in_file(given_config_source.file,
 						       argv[0], value, argv[2], 1);
 	}
 	else if (actions == ACTION_GET) {
@@ -623,26 +629,26 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 		return get_urlmatch(argv[0], argv[1]);
 	}
 	else if (actions == ACTION_UNSET) {
-		check_blob_write();
+		check_write();
 		check_argc(argc, 1, 2);
 		if (argc == 2)
-			return git_config_set_multivar_in_file(given_config_file,
+			return git_config_set_multivar_in_file(given_config_source.file,
 							       argv[0], NULL, argv[1], 0);
 		else
-			return git_config_set_in_file(given_config_file,
+			return git_config_set_in_file(given_config_source.file,
 						      argv[0], NULL);
 	}
 	else if (actions == ACTION_UNSET_ALL) {
-		check_blob_write();
+		check_write();
 		check_argc(argc, 1, 2);
-		return git_config_set_multivar_in_file(given_config_file,
+		return git_config_set_multivar_in_file(given_config_source.file,
 						       argv[0], NULL, argv[1], 1);
 	}
 	else if (actions == ACTION_RENAME_SECTION) {
 		int ret;
-		check_blob_write();
+		check_write();
 		check_argc(argc, 2, 2);
-		ret = git_config_rename_section_in_file(given_config_file,
+		ret = git_config_rename_section_in_file(given_config_source.file,
 							argv[0], argv[1]);
 		if (ret < 0)
 			return ret;
@@ -651,9 +657,9 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 	else if (actions == ACTION_REMOVE_SECTION) {
 		int ret;
-		check_blob_write();
+		check_write();
 		check_argc(argc, 1, 1);
-		ret = git_config_rename_section_in_file(given_config_file,
+		ret = git_config_rename_section_in_file(given_config_source.file,
 							argv[0], NULL);
 		if (ret < 0)
 			return ret;
diff --git a/cache.h b/cache.h
index 4c0043113c..bb0097e929 100644
--- a/cache.h
+++ b/cache.h
@@ -1148,6 +1148,12 @@ extern int update_server_info(int);
 #define CONFIG_INVALID_PATTERN 6
 #define CONFIG_GENERIC_ERROR 7
 
+struct git_config_source {
+	unsigned int use_stdin:1;
+	const char *file;
+	const char *blob;
+};
+
 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 *);
@@ -1157,8 +1163,7 @@ 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,
-				   const char *blob_ref,
+				   struct git_config_source *config_source,
 				   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 *);
diff --git a/config.c b/config.c
index 7f5b800ff3..6821cef00a 100644
--- a/config.c
+++ b/config.c
@@ -21,6 +21,7 @@ struct config_source {
 		} buf;
 	} u;
 	const char *name;
+	const char *path;
 	int die_on_error;
 	int linenr;
 	int eof;
@@ -101,12 +102,12 @@ static int handle_path_include(const char *path, struct config_include_data *inc
 	if (!is_absolute_path(path)) {
 		char *slash;
 
-		if (!cf || !cf->name)
+		if (!cf || !cf->path)
 			return error("relative config includes must come from files");
 
-		slash = find_last_dir_sep(cf->name);
+		slash = find_last_dir_sep(cf->path);
 		if (slash)
-			strbuf_add(&buf, cf->name, slash - cf->name + 1);
+			strbuf_add(&buf, cf->path, slash - cf->path + 1);
 		strbuf_addstr(&buf, path);
 		path = buf.buf;
 	}
@@ -1021,24 +1022,35 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data)
 	return ret;
 }
 
-int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+static int do_config_from_file(config_fn_t fn,
+		const char *name, const char *path, FILE *f, void *data)
 {
-	int ret;
-	FILE *f = fopen(filename, "r");
+	struct config_source top;
 
-	ret = -1;
-	if (f) {
-		struct config_source top;
+	top.u.file = f;
+	top.name = name;
+	top.path = path;
+	top.die_on_error = 1;
+	top.do_fgetc = config_file_fgetc;
+	top.do_ungetc = config_file_ungetc;
+	top.do_ftell = config_file_ftell;
 
-		top.u.file = f;
-		top.name = filename;
-		top.die_on_error = 1;
-		top.do_fgetc = config_file_fgetc;
-		top.do_ungetc = config_file_ungetc;
-		top.do_ftell = config_file_ftell;
+	return do_config_from(&top, fn, data);
+}
 
-		ret = do_config_from(&top, fn, data);
+static int git_config_from_stdin(config_fn_t fn, void *data)
+{
+	return do_config_from_file(fn, "<stdin>", NULL, stdin, data);
+}
+
+int git_config_from_file(config_fn_t fn, const char *filename, void *data)
+{
+	int ret = -1;
+	FILE *f;
 
+	f = fopen(filename, "r");
+	if (f) {
+		ret = do_config_from_file(fn, filename, filename, f, data);
 		fclose(f);
 	}
 	return ret;
@@ -1053,6 +1065,7 @@ int git_config_from_buf(config_fn_t fn, const char *name, const char *buf,
 	top.u.buf.len = len;
 	top.u.buf.pos = 0;
 	top.name = name;
+	top.path = NULL;
 	top.die_on_error = 0;
 	top.do_fgetc = config_buf_fgetc;
 	top.do_ungetc = config_buf_ungetc;
@@ -1161,8 +1174,7 @@ int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 }
 
 int git_config_with_options(config_fn_t fn, void *data,
-			    const char *filename,
-			    const char *blob_ref,
+			    struct git_config_source *config_source,
 			    int respect_includes)
 {
 	char *repo_config = NULL;
@@ -1180,10 +1192,12 @@ int git_config_with_options(config_fn_t fn, void *data,
 	 * If we have a specific filename, use it. Otherwise, follow the
 	 * regular lookup sequence.
 	 */
-	if (filename)
-		return git_config_from_file(fn, filename, data);
-	else if (blob_ref)
-		return git_config_from_blob_ref(fn, blob_ref, data);
+	if (config_source && config_source->use_stdin)
+		return git_config_from_stdin(fn, data);
+	else if (config_source && config_source->file)
+		return git_config_from_file(fn, config_source->file, data);
+	else if (config_source && config_source->blob)
+		return git_config_from_blob_ref(fn, config_source->blob, data);
 
 	repo_config = git_pathdup("config");
 	ret = git_config_early(fn, data, repo_config);
@@ -1194,7 +1208,7 @@ int git_config_with_options(config_fn_t fn, void *data,
 
 int git_config(config_fn_t fn, void *data)
 {
-	return git_config_with_options(fn, data, NULL, NULL, 1);
+	return git_config_with_options(fn, data, NULL, 1);
 }
 
 /*
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index 967359344d..c9c426c273 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -475,15 +475,28 @@ ein.bahn=strasse
 EOF
 
 test_expect_success 'alternative GIT_CONFIG' '
-	GIT_CONFIG=other-config git config -l >output &&
+	GIT_CONFIG=other-config git config --list >output &&
 	test_cmp expect output
 '
 
 test_expect_success 'alternative GIT_CONFIG (--file)' '
-	git config --file other-config -l > output &&
+	git config --file other-config --list >output &&
 	test_cmp expect output
 '
 
+test_expect_success 'alternative GIT_CONFIG (--file=-)' '
+	git config --file - --list <other-config >output &&
+	test_cmp expect output
+'
+
+test_expect_success 'setting a value in stdin is an error' '
+	test_must_fail git config --file - some.value foo
+'
+
+test_expect_success 'editing stdin is an error' '
+	test_must_fail git config --file - --edit
+'
+
 test_expect_success 'refer config from subdirectory' '
 	mkdir x &&
 	(
diff --git a/t/t1305-config-include.sh b/t/t1305-config-include.sh
index a70707620f..9ba2ba11c3 100755
--- a/t/t1305-config-include.sh
+++ b/t/t1305-config-include.sh
@@ -113,7 +113,7 @@ test_expect_success 'missing include files are ignored' '
 test_expect_success 'absolute includes from command line work' '
 	echo "[test]one = 1" >one &&
 	echo 1 >expect &&
-	git -c include.path="$PWD/one" config test.one >actual &&
+	git -c include.path="$(pwd)/one" config test.one >actual &&
 	test_cmp expect actual
 '
 
@@ -122,6 +122,36 @@ test_expect_success 'relative includes from command line fail' '
 	test_must_fail git -c include.path=one config test.one
 '
 
+test_expect_success 'absolute includes from blobs work' '
+	echo "[test]one = 1" >one &&
+	echo "[include]path=$(pwd)/one" >blob &&
+	blob=$(git hash-object -w blob) &&
+	echo 1 >expect &&
+	git config --blob=$blob test.one >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'relative includes from blobs fail' '
+	echo "[test]one = 1" >one &&
+	echo "[include]path=one" >blob &&
+	blob=$(git hash-object -w blob) &&
+	test_must_fail git config --blob=$blob test.one
+'
+
+test_expect_success 'absolute includes from stdin work' '
+	echo "[test]one = 1" >one &&
+	echo 1 >expect &&
+	echo "[include]path=\"$(pwd)/one\"" |
+	git config --file - test.one >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'relative includes from stdin line fail' '
+	echo "[test]one = 1" >one &&
+	echo "[include]path=one" |
+	test_must_fail git config --file - test.one
+'
+
 test_expect_success 'include cycles are detected' '
 	cat >.gitconfig <<-\EOF &&
 	[test]value = gitconfig