parse-options: move unsigned long option parsing out of pack-objects.c

The unsigned long option parsing (including 'k'/'m'/'g' suffix
parsing) is more widely applicable.  Add support for OPT_MAGNITUDE
to parse-options.h and change pack-objects.c use this support.

The error behavior on parse errors follows that of OPT_INTEGER.  The
name of the option that failed to parse is reported with a brief
message describing the expect format for the option argument and
then the full usage message for the command invoked.

This differs from the previous behavior for OPT_ULONG used in
pack-objects for --max-pack-size and --window-memory which used to
display the value supplied in the error message and did not display
the full usage message.

Signed-off-by: Charles Bailey <cbailey32@bloomberg.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/parse-options.c b/parse-options.c
index 80106c06b..3eceba446 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -180,6 +180,23 @@ static int get_value(struct parse_opt_ctx_t *p,
 			return opterror(opt, "expects a numerical value", flags);
 		return 0;
 
+	case OPTION_MAGNITUDE:
+		if (unset) {
+			*(unsigned long *)opt->value = 0;
+			return 0;
+		}
+		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
+			*(unsigned long *)opt->value = opt->defval;
+			return 0;
+		}
+		if (get_arg(p, opt, flags, &arg))
+			return -1;
+		if (!git_parse_ulong(arg, opt->value))
+			return opterror(opt,
+				"expects a non-negative integer value with an optional k/m/g suffix",
+				flags);
+		return 0;
+
 	default:
 		die("should not happen, someone must be hit on the forehead");
 	}