rev-list: allow -n<n> as shorthand for --max-count=<n>

Both -n<n> and -n <n> are supported.  POSIX versions of head(1) and
tail(1) allow their line limits to be parsed this way.  I find
--max-count to be a commonly used option, and also similar in spirit to
head/tail, so I decided to make life easier on my worn out (and lazy :)
fingers with this patch.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>

rev-list.c

@@ -749,6 +749,16 @@ int main(int argc, const char **argv)
 		struct commit *commit;
 		unsigned char sha1[20];
 
+		if (!strcmp(arg, "-n")) {
+			if (++i >= argc)
+				die("-n requires an argument");
+			max_count = atoi(argv[i]);
+			continue;
+		}
+		if (!strncmp(arg,"-n",2)) {
+			max_count = atoi(arg + 2);
+			continue;
+		}
 		if (!strncmp(arg, "--max-count=", 12)) {
 			max_count = atoi(arg + 12);
 			continue;

rev-parse.c

@@ -165,6 +165,21 @@ int main(int argc, char **argv)
 			show_file(arg);
 			continue;
 		}
+		if (!strcmp(arg,"-n")) {
+			if (++i >= argc)
+				die("-n requires an argument");
+			if ((filter & DO_FLAGS) && (filter & DO_REVS)) {
+				show(arg);
+				show(argv[i]);
+			}
+			continue;
+		}
+		if (!strncmp(arg,"-n",2)) {
+			if ((filter & DO_FLAGS) && (filter & DO_REVS))
+				show(arg);
+			continue;
+		}
+
 		if (*arg == '-') {
 			if (!strcmp(arg, "--")) {
 				as_is = 1;