reflog inspection: introduce shortcut "-g"

A short-hand "-g" for "git log --walk-reflogs" and "git
show-branch --reflog" makes it easier to access the reflog
info.

[jc: added -g to show-branch for symmetry]

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-rev-list.txt

@@ -191,7 +191,7 @@ limiting may be applied.
 	In addition to the '<commit>' listed on the command
 	line, read them from the standard input.
 
---walk-reflogs::
+-g, --walk-reflogs::
 
 	Instead of walking the commit ancestry chain, walk
 	reflog entries from the most recent one to older ones.

Documentation/git-show-branch.txt

@@ -11,7 +11,7 @@ SYNOPSIS
 'git-show-branch' [--all] [--remotes] [--topo-order] [--current]
 		[--more=<n> | --list | --independent | --merge-base]
 		[--no-name | --sha1-name] [--topics] [<rev> | <glob>]...
-'git-show-branch' --reflog[=<n>[,<base>]] [--list] <ref>
+'git-show-branch' (-g|--reflog)[=<n>[,<base>]] [--list] <ref>
 
 DESCRIPTION
 -----------
@@ -100,8 +100,8 @@ OPTIONS
 --reflog[=<n>[,<base>]] <ref>::
 	Shows <n> most recent ref-log entries for the given
 	ref.  If <base> is given, <n> entries going back from
-	that entry.  <base> can be specified as count or date
-
+	that entry.  <base> can be specified as count or date.
+	`-g` can be used as a short-hand for this option.
 
 Note that --more, --list, --independent and --merge-base options
 are mutually exclusive.

builtin-show-branch.c

@@ -649,11 +649,13 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 			dense = 0;
 		else if (!strcmp(arg, "--date-order"))
 			lifo = 0;
-		else if (!strcmp(arg, "--reflog")) {
+		else if (!strcmp(arg, "--reflog") || !strcmp(arg, "-g")) {
 			reflog = DEFAULT_REFLOG;
 		}
 		else if (!strncmp(arg, "--reflog=", 9))
 			parse_reflog_param(arg + 9, &reflog, &reflog_base);
+		else if (!strncmp(arg, "-g=", 3))
+			parse_reflog_param(arg + 3, &reflog, &reflog_base);
 		else
 			usage(show_branch_usage);
 		ac--; av++;

revision.c

@@ -868,7 +868,8 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				handle_reflog(revs, flags);
 				continue;
 			}
-			if (!strcmp(arg, "--walk-reflogs")) {
+			if (!strcmp(arg, "-g") ||
+					!strcmp(arg, "--walk-reflogs")) {
 				init_reflog_walk(&revs->reflog_info);
 				continue;
 			}