Merge branch 'maint-1.8.1' into maint

* maint-1.8.1:
  fast-export: fix argument name in error messages
  Documentation: distinguish between ref and offset deltas in pack-format

Author: gitster

Documentation/technical/pack-format.txt

@@ -26,7 +26,9 @@ Git pack format
 
      (deltified representation)
      n-byte type and length (3-bit type, (n-1)*7+4-bit length)
-     20-byte base object name
+     20-byte base object name if OBJ_REF_DELTA or a negative relative
+	 offset from the delta object's position in the pack if this
+	 is an OBJ_OFS_DELTA object
      compressed delta data
 
      Observation: length of each object is encoded in a variable

builtin/fast-export.c

@@ -43,7 +43,7 @@ static int parse_opt_signed_tag_mode(const struct option *opt,
 	else if (!strcmp(arg, "strip"))
 		signed_tag_mode = STRIP;
 	else
-		return error("Unknown signed-tag mode: %s", arg);
+		return error("Unknown signed-tags mode: %s", arg);
 	return 0;
 }
 
@@ -416,7 +416,7 @@ static void handle_tag(const char *name, struct tag *tag)
 			switch(signed_tag_mode) {
 			case ABORT:
 				die ("Encountered signed tag %s; use "
-				     "--signed-tag=<mode> to handle it.",
+				     "--signed-tags=<mode> to handle it.",
 				     sha1_to_hex(tag->object.sha1));
 			case WARN:
 				warning ("Exporting signed tag %s",