send-email: relay '-v N' to format-patch

send-email relays unrecognized arguments to its format-patch call.
Passing '-v N' leads to an error because -v is consumed as
send-email's --validate.  For example,

  git send-email -v 3 @{u}

fails with

  fatal: ambiguous argument '3': unknown revision or path not in the
  working tree.  [...]

To prevent this, add the short --reroll-count option to send-email's
main option list and explicitly provide it to the format-patch call.

There other format-patch options that send-email doesn't relay
properly, including at least -n, -N, and the diff option -D.  Punt on
these because dealing with them is more complicated:

 * they would require configuring send-email to not ignore option case

 * send-email makes three GetOptions() calls with different sets of
   options, the last being the main set of options.  Unlike -v, which
   is consumed by the last GetOptions call, the -n, -N, and -D options
   are consumed as abbreviations by the earlier calls.

Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -220,6 +220,10 @@ my $compose_filename;
 my $force = 0;
 my $dump_aliases = 0;
 
+# Variables to prevent short format-patch options from being captured
+# as abbreviated send-email options
+my $reroll_count;
+
 # Handle interactive edition of files.
 my $multiedit;
 my $editor;
@@ -542,6 +546,7 @@ my %options = (
 		    "batch-size=i" => \$batch_size,
 		    "relogin-delay=i" => \$relogin_delay,
 		    "git-completion-helper" => \$git_completion_helper,
+		    "v=s" => \$reroll_count,
 );
 $rc = GetOptions(%options);
 
@@ -782,7 +787,9 @@ if (@rev_list_opts) {
 	die __("Cannot run git format-patch from outside a repository\n")
 		unless $repo;
 	require File::Temp;
-	push @files, $repo->command('format-patch', '-o', File::Temp::tempdir(CLEANUP => 1), @rev_list_opts);
+	push @files, $repo->command('format-patch', '-o', File::Temp::tempdir(CLEANUP => 1),
+				    defined $reroll_count ? ('-v', $reroll_count) : (),
+				    @rev_list_opts);
 }
 
 @files = handle_backup_files(@files);

t/t9001-send-email.sh

@@ -2334,6 +2334,12 @@ test_expect_success $PREREQ 'test that send-email works outside a repo' '
 		"$(pwd)/0001-add-main.patch"
 '
 
+test_expect_success $PREREQ 'send-email relays -v 3 to format-patch' '
+	test_when_finished "rm -f out" &&
+	git send-email --dry-run -v 3 -1 >out &&
+	grep "PATCH v3" out
+'
+
 test_expect_success $PREREQ 'test that sendmail config is rejected' '
 	test_config sendmail.program sendmail &&
 	test_must_fail git send-email \