update-index: do not die too early in a read-only repository.

diff --git a/Documentation/git-check-ref-format.txt b/Documentation/git-check-ref-format.txt
index 3ea720dd005f7a9b4a66a419cf5438a3a7d0fa8b..13a5f43049c25e1df3bcbcbbed482acce0cebc8b 100644 (file)
--- a/Documentation/git-check-ref-format.txt
+++ b/Documentation/git-check-ref-format.txt
@@ -19,8 +19,9 @@ branch head is stored under `$GIT_DIR/refs/heads` directory, and
 a tag is stored under `$GIT_DIR/refs/tags` directory.  git
 imposes the following rules on how refs are named:
 
-. It could be named hierarchically (i.e. separated with slash
-  `/`), but each of its component cannot begin with a dot `.`;
+. It can include slash `/` for hierarchical (directory)
+  grouping, but no slash-separated component can begin with a
+  dot `.`;
 
 . It cannot have two consecutive dots `..` anywhere;