git-init: accept --bare option

It is unfortunate that "git init --bare" does not work and the only reason
why "init" did not learn its own "--bare" option is because "git --bare
init" already does the job (and as an option to the git 'potty', it is
more generic solution).

This teaches "git init" its own "--bare" option, so that both "git --bare init"
and "git init --bare" works mostly the same way.

[jc: rewrote the log message and added test]

Signed-off-by: Luciano Rocha <strange@nsk.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-init.txt

@@ -8,7 +8,7 @@ git-init - Create an empty git repository or reinitialize an existing one
 
 SYNOPSIS
 --------
-'git-init' [-q | --quiet] [--template=<template_directory>] [--shared[=<permissions>]]
+'git-init' [-q | --quiet] [--bare] [--template=<template_directory>] [--shared[=<permissions>]]
 
 
 OPTIONS
@@ -20,6 +20,11 @@ OPTIONS
 
 Only print error and warning messages, all other output will be suppressed.
 
+--bare::
+
+Create a bare repository. If GIT_DIR environment is not set, it is set to the
+current working directory.
+
 --template=<template_directory>::
 
 Provide the directory from which templates will be used.  The default template

builtin-init-db.c

@@ -364,7 +364,7 @@ static int guess_repository_type(const char *git_dir)
 }
 
 static const char init_db_usage[] =
-"git-init [-q | --quiet] [--template=<template-directory>] [--shared]";
+"git-init [-q | --quiet] [--bare] [--template=<template-directory>] [--shared[=<permissions>]]";
 
 /*
  * If you want to, you can share the DB area with any number of branches.
@@ -383,7 +383,12 @@ int cmd_init_db(int argc, const char **argv, const char *prefix)
 		const char *arg = argv[1];
 		if (!prefixcmp(arg, "--template="))
 			template_dir = arg+11;
-		else if (!strcmp(arg, "--shared"))
+		else if (!strcmp(arg, "--bare")) {
+			static char git_dir[PATH_MAX+1];
+			is_bare_repository_cfg = 1;
+			setenv(GIT_DIR_ENVIRONMENT, getcwd(git_dir,
+						sizeof(git_dir)), 0);
+		} else if (!strcmp(arg, "--shared"))
 			shared_repository = PERM_GROUP;
 		else if (!prefixcmp(arg, "--shared="))
 			shared_repository = git_config_perm("arg", arg+9);

t/t0001-init.sh

@@ -79,6 +79,17 @@ test_expect_success 'GIT_DIR bare' '
 	check_config git-dir-bare.git true unset
 '
 
+test_expect_success 'init --bare' '
+
+	(
+		unset GIT_DIR GIT_WORK_TREE GIT_CONFIG
+		mkdir git-init-bare.git &&
+		cd git-init-bare.git &&
+		git init --bare
+	) &&
+	check_config git-init-bare.git true unset
+'
+
 test_expect_success 'GIT_DIR non-bare' '
 
 	(