git-tag: introduce long forms for the options

Long forms are better to memorize and more reliably uniform across
commands.

Design notes:

-u,--local-user is named following the analogous gnupg option.

-l,--list is not an argument taking option but a mode switch.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-tag.txt

@@ -43,22 +43,27 @@ GnuPG key for signing.
 OPTIONS
 -------
 -a::
+--annotate::
 	Make an unsigned, annotated tag object
 
 -s::
+--sign::
 	Make a GPG-signed tag, using the default e-mail address's key
 
 -u <key-id>::
+--local-user=<key-id>::
 	Make a GPG-signed tag, using the given key
 
 -f::
 --force::
 	Replace an existing tag with the given name (instead of failing)
 
 -d::
+--delete::
 	Delete existing tags with the given names.
 
 -v::
+--verify::
 	Verify the gpg signature of the given tag names.
 
 -n<num>::
@@ -69,20 +74,26 @@ OPTIONS
 	If the tag is not annotated, the commit message is displayed instead.
 
 -l <pattern>::
-	List tags with names that match the given pattern (or all if no pattern is given).
-	Typing "git tag" without arguments, also lists all tags.
+--list <pattern>::
+	List tags with names that match the given pattern (or all if no
+	pattern is given).  Running "git tag" without arguments also
+	lists all tags. The pattern is a shell wildcard (i.e., matched
+	using fnmatch(3)).  Multiple patterns may be given; if any of
+	them matches, the tag is shown.
 
 --contains <commit>::
 	Only list tags which contain the specified commit.
 
 -m <msg>::
+--message=<msg>::
 	Use the given tag message (instead of prompting).
 	If multiple `-m` options are given, their values are
 	concatenated as separate paragraphs.
 	Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
 	is given.
 
 -F <file>::
+--file=<file>::
 	Take the tag message from the given file.  Use '-' to
 	read the message from the standard input.
 	Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`

builtin/tag.c

@@ -377,21 +377,21 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 	struct msg_arg msg = { 0, STRBUF_INIT };
 	struct commit_list *with_commit = NULL;
 	struct option options[] = {
-		OPT_BOOLEAN('l', NULL, &list, "list tag names"),
+		OPT_BOOLEAN('l', "list", &list, "list tag names"),
 		{ OPTION_INTEGER, 'n', NULL, &lines, "n",
 				"print <n> lines of each tag message",
 				PARSE_OPT_OPTARG, NULL, 1 },
-		OPT_BOOLEAN('d', NULL, &delete, "delete tags"),
-		OPT_BOOLEAN('v', NULL, &verify, "verify tags"),
+		OPT_BOOLEAN('d', "delete", &delete, "delete tags"),
+		OPT_BOOLEAN('v', "verify", &verify, "verify tags"),
 
 		OPT_GROUP("Tag creation options"),
-		OPT_BOOLEAN('a', NULL, &annotate,
+		OPT_BOOLEAN('a', "annotate", &annotate,
 					"annotated tag, needs a message"),
-		OPT_CALLBACK('m', NULL, &msg, "message",
+		OPT_CALLBACK('m', "message", &msg, "message",
 			     "tag message", parse_msg_arg),
-		OPT_FILENAME('F', NULL, &msgfile, "read message from file"),
-		OPT_BOOLEAN('s', NULL, &sign, "annotated and GPG-signed tag"),
-		OPT_STRING('u', NULL, &keyid, "key-id",
+		OPT_FILENAME('F', "file", &msgfile, "read message from file"),
+		OPT_BOOLEAN('s', "sign", &sign, "annotated and GPG-signed tag"),
+		OPT_STRING('u', "local-user", &keyid, "key-id",
 					"use another key to sign the tag"),
 		OPT__FORCE(&force, "replace the tag if exists"),