Merge branch 'po/help-guides'

"git help" learned "-g" option to show the list of guides just like
list of commands are given with "-a".

* po/help-guides:
  doc: include --guide option description for "git help"
  help: mention -a and -g option, and 'git help <concept>' usage.
  builtin/help.c: add list_common_guides_help() function
  builtin/help.c: add --guide option
  builtin/help.c: split "-a" processing into two

Documentation/git-help.txt

@@ -8,31 +8,45 @@ git-help - Display help information about Git
 SYNOPSIS
 --------
 [verse]
-'git help' [-a|--all|-i|--info|-m|--man|-w|--web] [COMMAND]
+'git help' [-a|--all] [-g|--guide]
+	   [-i|--info|-m|--man|-w|--web] [COMMAND|GUIDE]
 
 DESCRIPTION
 -----------
 
-With no options and no COMMAND given, the synopsis of the 'git'
+With no options and no COMMAND or GUIDE given, the synopsis of the 'git'
 command and a list of the most commonly used Git commands are printed
 on the standard output.
 
-If the option '--all' or '-a' is given, then all available commands are
+If the option '--all' or '-a' is given, all available commands are
 printed on the standard output.
 
-If a Git subcommand is named, a manual page for that subcommand is brought
-up. The 'man' program is used by default for this purpose, but this
-can be overridden by other options or configuration variables.
+If the option '--guide' or '-g' is given, a list of the useful
+Git guides is also printed on the standard output.
+
+If a command, or a guide, is given, a manual page for that command or
+guide is brought up. The 'man' program is used by default for this
+purpose, but this can be overridden by other options or configuration
+variables.
 
 Note that `git --help ...` is identical to `git help ...` because the
 former is internally converted into the latter.
 
+To display the linkgit:git[1] man page, use `git help git`.
+
+This page can be displayed with 'git help help' or `git help --help`
+
 OPTIONS
 -------
 -a::
 --all::
 	Prints all the available commands on the standard output. This
-	option supersedes any other option.
+	option overrides any given command or guide name.
+
+-g::
+--guides::
+	Prints a list of useful guides on the standard output. This
+	option overrides any given command or guide name.
 
 -i::
 --info::

builtin/help.c

@@ -36,10 +36,12 @@ enum help_format {
 static const char *html_path;
 
 static int show_all = 0;
+static int show_guides = 0;
 static unsigned int colopts;
 static enum help_format help_format = HELP_FORMAT_NONE;
 static struct option builtin_help_options[] = {
-	OPT_BOOLEAN('a', "all", &show_all, N_("print all available commands")),
+	OPT_BOOL('a', "all", &show_all, N_("print all available commands")),
+	OPT_BOOL('g', "guides", &show_guides, N_("print list of useful guides")),
 	OPT_SET_INT('m', "man", &help_format, N_("show man page"), HELP_FORMAT_MAN),
 	OPT_SET_INT('w', "web", &help_format, N_("show manual in web browser"),
 			HELP_FORMAT_WEB),
@@ -49,7 +51,7 @@ static struct option builtin_help_options[] = {
 };
 
 static const char * const builtin_help_usage[] = {
-	N_("git help [--all] [--man|--web|--info] [command]"),
+	N_("git help [--all] [--guides] [--man|--web|--info] [command]"),
 	NULL
 };
 
@@ -413,6 +415,37 @@ static void show_html_page(const char *git_cmd)
 	open_html(page_path.buf);
 }
 
+static struct {
+	const char *name;
+	const char *help;
+} common_guides[] = {
+	{ "attributes", "Defining attributes per path" },
+	{ "glossary", "A Git glossary" },
+	{ "ignore", "Specifies intentionally untracked files to ignore" },
+	{ "modules", "Defining submodule properties" },
+	{ "revisions", "Specifying revisions and ranges for Git" },
+	{ "tutorial", "A tutorial introduction to Git (for version 1.5.1 or newer)" },
+	{ "workflows", "An overview of recommended workflows with Git"},
+};
+
+static void list_common_guides_help(void)
+{
+	int i, longest = 0;
+
+	for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
+		if (longest < strlen(common_guides[i].name))
+			longest = strlen(common_guides[i].name);
+	}
+
+	puts(_("The common Git guides are:\n"));
+	for (i = 0; i < ARRAY_SIZE(common_guides); i++) {
+		printf("   %s   ", common_guides[i].name);
+		mput_char(' ', longest - strlen(common_guides[i].name));
+		puts(_(common_guides[i].help));
+	}
+	putchar('\n');
+}
+
 int cmd_help(int argc, const char **argv, const char *prefix)
 {
 	int nongit;
@@ -428,7 +461,16 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 		git_config(git_help_config, NULL);
 		printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
 		list_commands(colopts, &main_cmds, &other_cmds);
+	}
+
+	if (show_guides)
+		list_common_guides_help();
+
+	if (show_all || show_guides) {
 		printf("%s\n", _(git_more_info_string));
+		/*
+		* We're done. Ignore any remaining args
+		*/
 		return 0;
 	}
 

git.c

@@ -13,7 +13,9 @@ const char git_usage_string[] =
 	"           <command> [<args>]";
 
 const char git_more_info_string[] =
-	N_("See 'git help <command>' for more information on a specific command.");
+	N_("'git help -a' and 'git help -g' lists available subcommands and some\n"
+	   "concept guides. See 'git help <command>' or 'git help <concept>'\n"
+	   "to read about a specific subcommand or concept.");
 
 static struct startup_info git_startup_info;
 static int use_pager = -1;