config: allow disabling config includes

Documentation/git-config.adoc

@@ -476,7 +476,7 @@ GIT_CONFIG_SYSTEM::
 GIT_CONFIG_NOSYSTEM::
 	Whether to skip reading settings from the system-wide
 	$(prefix)/etc/gitconfig file. See linkgit:git[1] for details.
-
++
 See also <<FILES>>.
 
 GIT_CONFIG_COUNT::
@@ -502,6 +502,11 @@ GIT_CONFIG::
 	historical compatibility; there is generally no reason to use it
 	instead of the `--file` option.
 
+GIT_CONFIG_INCLUDES::
+	If GIT_CONFIG_INCLUDES is set to 0, then Git will not follow
+	`include.path` or `includeIf.*.path` directives when reading
+	configuration files.
+
 [[EXAMPLES]]
 EXAMPLES
 --------

Documentation/git.adoc

@@ -12,7 +12,7 @@ SYNOPSIS
 'git' [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]
     [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
     [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--no-lazy-fetch]
-    [--no-optional-locks] [--no-advice] [--bare] [--git-dir=<path>]
+    [--no-optional-locks] [--no-advice] [--no-includes] [--bare] [--git-dir=<path>]
     [--work-tree=<path>] [--namespace=<name>] [--config-env=<name>=<envvar>]
     <command> [<args>]
 
@@ -194,6 +194,10 @@ If you just want to run git as if it was started in `<path>` then use
 --no-advice::
 	Disable all advice hints from being printed.
 
+--no-includes::
+	Disable all `include.path` and `includeIf.*` config directives.
+	See linkgit:git-config[1] for more information.
+
 --literal-pathspecs::
 	Treat pathspecs literally (i.e. no globbing, no pathspec magic).
 	This is equivalent to setting the `GIT_LITERAL_PATHSPECS` environment

config.c

@@ -1595,9 +1595,14 @@ int config_with_options(config_fn_t fn, void *data,
 			const struct config_options *opts)
 {
 	struct config_include_data inc = CONFIG_INCLUDE_INIT;
+	int respect_includes = opts->respect_includes;
 	int ret;
 
-	if (opts->respect_includes) {
+	if (respect_includes &&
+	    !git_env_bool(CONFIG_INCLUDES_ENVIRONMENT, 1))
+		respect_includes = 0;
+
+	if (respect_includes) {
 		inc.fn = fn;
 		inc.data = data;
 		inc.opts = opts;

environment.h

@@ -52,6 +52,12 @@
  */
 #define GIT_ADVICE_ENVIRONMENT "GIT_ADVICE"
 
+/*
+ * Environment variable used to prevent following include.path or includeIf.*
+ * config directives.
+ */
+#define CONFIG_INCLUDES_ENVIRONMENT "GIT_CONFIG_INCLUDES"
+
 /*
  * Environment variable used in handshaking the wire protocol.
  * Contains a colon ':' separated list of keys with optional values

git.c

@@ -40,7 +40,7 @@ const char git_usage_string[] =
 	N_("git [-v | --version] [-h | --help] [-C <path>] [-c <name>=<value>]\n"
 	   "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
 	   "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--no-lazy-fetch]\n"
-	   "           [--no-optional-locks] [--no-advice] [--bare] [--git-dir=<path>]\n"
+	   "           [--no-optional-locks] [--no-advice] [--no-includes] [--bare] [--git-dir=<path>]\n"
 	   "           [--work-tree=<path>] [--namespace=<name>] [--config-env=<name>=<envvar>]\n"
 	   "           <command> [<args>]");
 
@@ -354,6 +354,10 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			setenv(GIT_ADVICE_ENVIRONMENT, "0", 1);
 			if (envchanged)
 				*envchanged = 1;
+		} else if (!strcmp(cmd, "--no-includes")) {
+			setenv(CONFIG_INCLUDES_ENVIRONMENT, "0", 1);
+			if (envchanged)
+				*envchanged = 1;
 		} else {
 			fprintf(stderr, _("unknown option: %s\n"), cmd);
 			usage(git_usage_string);

t/t1305-config-include.sh

@@ -396,4 +396,39 @@ test_expect_success 'onbranch without repository but explicit nonexistent Git di
 	test_must_fail nongit git --git-dir=nonexistent config get foo.bar
 '
 
+test_expect_success 'GIT_CONFIG_INCLUDES=0 disables include.path and includeIf' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config set include.path config.inc &&
+		git config set "includeIf.gitdir:*.path" config2.inc &&
+		git config set -f .git/config.inc foo.bar from-include &&
+		git config set -f .git/config2.inc foo.baz from-includeif &&
+		git config get foo.bar &&
+		git config get foo.baz &&
+		test_must_fail env GIT_CONFIG_INCLUDES=0 git config get foo.bar &&
+		test_must_fail env GIT_CONFIG_INCLUDES=0 git config get foo.baz &&
+		test_must_fail git --no-includes config get foo.bar &&
+		test_must_fail git --no-includes config get foo.baz &&
+		git config get --includes foo.bar &&
+		test_must_fail env GIT_CONFIG_INCLUDES=0 git config get --includes foo.bar &&
+		test_must_fail git --no-includes config get --includes foo.bar
+	)
+'
+
+test_expect_success 'GIT_CONFIG_INCLUDES=0 blocks included alias override' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	(
+		cd repo &&
+		git config set alias.test false &&
+		git config set include.path config.inc &&
+		git config set -f .git/config.inc alias.test status &&
+		git test &&
+		test_must_fail env GIT_CONFIG_INCLUDES=0 git test &&
+		test_must_fail git --no-includes test
+	)
+'
+
 test_done