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 7dc1bdb6ef62f1325f8cf0567aa65c56728522ec..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;
 
@@ -45,6 +46,8 @@ refname expressions (see gitlink:git-rev-parse[1]).  Namely:
 
 . colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
   value and store it in dstref" in fetch and push operations.
+  It may also be used to select a specific object such as with
+  gitlink:git-cat-file[1] "git-cat-file blob v1.3.3:refs.c".
 
 
 GIT