pack-objects: new option --honor-pack-keep

This adds a new option to pack-objects which will cause it to ignore an
object which appears in a local pack which has a .keep file, even if it
was specified for packing.

This option will be used by the porcelain repack.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-pack-objects.txt

@@ -109,6 +109,11 @@ base-name::
 	The default is unlimited, unless the config variable
 	`pack.packSizeLimit` is set.
 
+--honor-pack-keep::
+	This flag causes an object already in a local pack that
+	has a .keep file to be ignored, even if it appears in the
+	standard input.
+
 --incremental::
 	This flag causes an object already in a pack ignored
 	even if it appears in the standard input.

builtin-pack-objects.c

@@ -71,6 +71,7 @@ static int reuse_delta = 1, reuse_object = 1;
 static int keep_unreachable, unpack_unreachable, include_tag;
 static int local;
 static int incremental;
+static int ignore_packed_keep;
 static int allow_ofs_delta;
 static const char *base_name;
 static int progress = 1;
@@ -703,6 +704,8 @@ static int add_object_entry(const unsigned char *sha1, enum object_type type,
 				return 0;
 			if (local && !p->pack_local)
 				return 0;
+			if (ignore_packed_keep && p->pack_local && p->pack_keep)
+				return 0;
 		}
 	}
 
@@ -2042,6 +2045,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			incremental = 1;
 			continue;
 		}
+		if (!strcmp("--honor-pack-keep", arg)) {
+			ignore_packed_keep = 1;
+			continue;
+		}
 		if (!prefixcmp(arg, "--compression=")) {
 			char *end;
 			int level = strtoul(arg+14, &end, 0);