[PATCH v3 2/6] blame: replace usage end blurb with better option spec

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the "git blame -h" output to be consistent with "git bundle
-h"'s, i.e. before this we'd emit:

    $ git blame -h
    usage: git blame [<options>] [<rev-opts>] [<rev>] [--] <file>

        <rev-opts> are documented in git-rev-list(1)
    [...]

Now instead of that we'll emit:

    $ git blame -h
    usage: git blame [<options>] [<git rev-list args>] [<rev>] [--] <file>
    [...]

This makes it consistent with the usage spec used for "git bundle":

    $ git bundle -h
    usage: git bundle create [<options>] <file> <git-rev-list args>
    [...]

The use of this in "blame" dated back to 5817da01434 (git-blame:
migrate to incremental parse-option [1/2], 2008-07-08), and the use in
"bundle" to 2e0afafebd8 (Add git-bundle: move objects and
references by archive, 2007-02-22).

Once we get rid of this special case we can also use usage_msg_opt()
to emit the error message we'd get on an invalid "-L <range>"
argument, which means we can get rid of the old-style "blame_usage"
variable entirely. This makes the output friendlier, before we'd emit say:

    $ git blame -L1,2,3,4 Makefile
    usage: git blame [<options>] [<rev-opts>] [<rev>] [--] <file>
    $

Now we'll instead emit:

    $ git blame -L1,2,3,4 Makefile
    fatal: Invalid -L <range> parameter

    usage: git blame [<options>] [<git rev-list args>] [<rev>] [--] <file>
    [...]
    $

The "[...]" there elides the "git blame" option summary.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/blame.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/builtin/blame.c b/builtin/blame.c
index 641523ff9af..e469829bc76 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -29,12 +29,8 @@
 #include "refs.h"
 #include "tag.h"
 
-static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");
-
 static const char *blame_opt_usage[] = {
-	blame_usage,
-	"",
-	N_("<rev-opts> are documented in git-rev-list(1)"),
+	N_("git blame [<options>] [<git rev-list args>] [<rev>] [--] <file>"),
 	NULL
 };
 
@@ -1107,7 +1103,8 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 				    nth_line_cb, &sb, lno, anchor,
 				    &bottom, &top, sb.path,
 				    the_repository->index))
-			usage(blame_usage);
+			usage_msg_opt(_("Invalid -L <range> parameter"),
+				      blame_opt_usage, options);
 		if ((!lno && (top || bottom)) || lno < bottom)
 			die(Q_("file %s has only %lu line",
 			       "file %s has only %lu lines",
-- 
2.33.0.995.ga5ea46173a2