Allow pickaxe and diff-filter options to be used by git log.

Handle the -S option when passed to git log such that only the
appropriate commits are displayed.  Also per Junio's comments, do
the same for "--diff-filter", so that it too can be used as an option
to git log.  By default no patch or diff information is displayed.

Signed-off-by: Sean Estabrooks <seanlkml@sympatico.ca>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-log.c

@@ -19,6 +19,13 @@ static int cmd_log_wc(int argc, const char **argv, char **envp,
 	rev->commit_format = CMIT_FMT_DEFAULT;
 	rev->verbose_header = 1;
 	argc = setup_revisions(argc, argv, rev, "HEAD");
+	if (rev->always_show_header) {
+		if (rev->diffopt.pickaxe || rev->diffopt.filter) {
+			rev->always_show_header = 0;
+			if (rev->diffopt.output_format == DIFF_FORMAT_RAW)
+				rev->diffopt.output_format = DIFF_FORMAT_NO_OUTPUT;
+		}
+	}
 
 	if (argc > 1)
 		die("unrecognized argument: %s", argv[1]);