parse-options: multi-word argh should use dash to separate words

"When you need to use space, use dash" is a strange way to say that
you must not use a space.  Because it is more common for the command
line descriptions to use dashed-multi-words, you do not even want to
use spaces in these places.  Rephrase the documentation to avoid
this strangeness.

Fix a few existing multi-word argument help strings, i.e.

 - GPG key-ids given to -S/--gpg-sign are "key-id";
 - Refs used for storing notes are "notes-ref"; and
 - Expiry timestamps given to --expire are "expiry-date".

and update the corresponding documentation pages.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-cherry-pick.txt

@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git cherry-pick' [--edit] [-n] [-m parent-number] [-s] [-x] [--ff]
-		  [-S[<keyid>]] <commit>...
+		  [-S[<key-id>]] <commit>...
 'git cherry-pick' --continue
 'git cherry-pick' --quit
 'git cherry-pick' --abort
@@ -101,8 +101,8 @@ effect to your index in a row.
 --signoff::
 	Add Signed-off-by line at the end of the commit message.
 
--S[<keyid>]::
+-S[<key-id>]::
---gpg-sign[=<keyid>]::
+--gpg-sign[=<key-id>]::
 	GPG-sign commits.
 
 --ff::

Documentation/git-commit.txt

@@ -13,7 +13,7 @@ SYNOPSIS
 	   [-F <file> | -m <msg>] [--reset-author] [--allow-empty]
 	   [--allow-empty-message] [--no-verify] [-e] [--author=<author>]
 	   [--date=<date>] [--cleanup=<mode>] [--[no-]status]
-	   [-i | -o] [-S[<keyid>]] [--] [<file>...]
+	   [-i | -o] [-S[<key-id>]] [--] [<file>...]
 
 DESCRIPTION
 -----------

Documentation/git-merge.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
-	[-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
+	[-s <strategy>] [-X <strategy-option>] [-S[<key-id>]]
 	[--[no-]rerere-autoupdate] [-m <msg>] [<commit>...]
 'git merge' <msg> HEAD <commit>...
 'git merge' --abort

Documentation/git-notes.txt

@@ -14,7 +14,7 @@ SYNOPSIS
 'git notes' append [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
 'git notes' edit [<object>]
 'git notes' show [<object>]
-'git notes' merge [-v | -q] [-s <strategy> ] <notes_ref>
+'git notes' merge [-v | -q] [-s <strategy> ] <notes-ref>
 'git notes' merge --commit [-v | -q]
 'git notes' merge --abort [-v | -q]
 'git notes' remove [--ignore-missing] [--stdin] [<object>...]

Documentation/git-rev-parse.txt

@@ -290,14 +290,14 @@ The lines after the separator describe the options.
 Each line of options has this format:
 
 ------------
-<opt_spec><flags>*<arg_hint>? SP+ help LF
+<opt-spec><flags>*<arg-hint>? SP+ help LF
 ------------
 
-`<opt_spec>`::
+`<opt-spec>`::
 	its format is the short option character, then the long option name
 	separated by a comma. Both parts are not required, though at least one
 	is necessary. `h,help`, `dry-run` and `f` are all three correct
-	`<opt_spec>`.
+	`<opt-spec>`.
 
 `<flags>`::
 	`<flags>` are of `*`, `=`, `?` or `!`.
@@ -313,11 +313,11 @@ Each line of options has this format:
 
 	* Use `!` to not make the corresponding negated long option available.
 
-`<arg_hint>`::
+`<arg-hint>`::
-	`<arg_hint>`, if specified, is used as a name of the argument in the
+	`<arg-hint>`, if specified, is used as a name of the argument in the
-	help output, for options that take arguments. `<arg_hint>` is
+	help output, for options that take arguments. `<arg-hint>` is
-	terminated by the first whitespace. When you need to use space in the
+	terminated by the first whitespace.  It is customary to use a
-	argument hint use dash instead.
+	dash to separate words in a multi-word argument hint.
 
 The remainder of the line, after stripping the spaces, is used
 as the help associated to the option.

Documentation/git-revert.txt

@@ -8,7 +8,7 @@ git-revert - Revert some existing commits
 SYNOPSIS
 --------
 [verse]
-'git revert' [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<keyid>]] <commit>...
+'git revert' [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<key-id>]] <commit>...
 'git revert' --continue
 'git revert' --quit
 'git revert' --abort
@@ -80,8 +80,8 @@ more details.
 This is useful when reverting more than one commits'
 effect to your index in a row.
 
--S[<keyid>]::
+-S[<key-id>]::
---gpg-sign[=<keyid>]::
+--gpg-sign[=<key-id>]::
 	GPG-sign commits.
 
 -s::

builtin/checkout.c

@@ -1095,7 +1095,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "detach", &opts.force_detach, N_("detach the HEAD at named commit")),
 		OPT_SET_INT('t', "track",  &opts.track, N_("set upstream info for new branch"),
 			BRANCH_TRACK_EXPLICIT),
-		OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new branch"), N_("new unparented branch")),
+		OPT_STRING(0, "orphan", &opts.new_orphan_branch, N_("new-branch"), N_("new unparented branch")),
 		OPT_SET_INT('2', "ours", &opts.writeout_stage, N_("checkout our version for unmerged files"),
 			    2),
 		OPT_SET_INT('3', "theirs", &opts.writeout_stage, N_("checkout their version for unmerged files"),

builtin/commit.c

@@ -1472,7 +1472,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('e', "edit", &edit_flag, N_("force edit of commit")),
 		OPT_STRING(0, "cleanup", &cleanup_arg, N_("default"), N_("how to strip spaces and #comments from message")),
 		OPT_BOOL(0, "status", &include_status, N_("include status in commit message template")),
-		{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key id"),
+		{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
 		  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 		/* end commit message options */
 

builtin/merge.c

@@ -220,7 +220,7 @@ static struct option builtin_merge_options[] = {
 	OPT_BOOL(0, "abort", &abort_current_merge,
 		N_("abort the current in-progress merge")),
 	OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
-	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key id"),
+	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_END()

builtin/notes.c

@@ -939,7 +939,7 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
 	int result;
 	const char *override_notes_ref = NULL;
 	struct option options[] = {
-		OPT_STRING(0, "ref", &override_notes_ref, N_("notes_ref"),
+		OPT_STRING(0, "ref", &override_notes_ref, N_("notes-ref"),
 			   N_("use notes from <notes_ref>")),
 		OPT_END()
 	};

builtin/revert.c

@@ -89,7 +89,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 		OPT_STRING(0, "strategy", &opts->strategy, N_("strategy"), N_("merge strategy")),
 		OPT_CALLBACK('X', "strategy-option", &opts, N_("option"),
 			N_("option for merge strategy"), option_parse_x),
-		{ OPTION_STRING, 'S', "gpg-sign", &opts->gpg_sign, N_("key id"),
+		{ OPTION_STRING, 'S', "gpg-sign", &opts->gpg_sign, N_("key-id"),
 		  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 		OPT_END(),
 		OPT_END(),

builtin/tag.c

@@ -513,7 +513,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('s', "sign", &opt.sign, N_("annotated and GPG-signed tag")),
 		OPT_STRING(0, "cleanup", &cleanup_arg, N_("mode"),
 			N_("how to strip spaces and #comments from message")),
-		OPT_STRING('u', "local-user", &keyid, N_("key id"),
+		OPT_STRING('u', "local-user", &keyid, N_("key-id"),
 					N_("use another key to sign the tag")),
 		OPT__FORCE(&force, N_("replace the tag if exists")),
 		OPT_COLUMN(0, "column", &colopts, N_("show tag list in columns")),

parse-options.h

@@ -143,7 +143,7 @@ struct option {
 	{ OPTION_CALLBACK, (s), (l), (v), N_("time"),(h), 0,	\
 	  parse_opt_approxidate_cb }
 #define OPT_EXPIRY_DATE(s, l, v, h) \
-	{ OPTION_CALLBACK, (s), (l), (v), N_("expiry date"),(h), 0,	\
+	{ OPTION_CALLBACK, (s), (l), (v), N_("expiry-date"),(h), 0,	\
 	  parse_opt_expiry_date_cb }
 #define OPT_CALLBACK(s, l, v, a, h, f) \
 	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), 0, (f) }