read-tree: use OPT_BOOL instead of OPT_SET_INT

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 1abf078c4e1c79ee11b05c2a26d83ba28c809a66..506431267ed0ef15bce2570d3f1bf69e7268e8f0 100644 (file)
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -783,10 +783,11 @@ core.sparseCheckout::
        linkgit:git-read-tree[1] for more information.
 
 core.abbrev::
-       Set the length object names are abbreviated to.  If unspecified,
-       many commands abbreviate to 7 hexdigits, which may not be enough
-       for abbreviated object names to stay unique for sufficiently long
-       time.
+       Set the length object names are abbreviated to.  If
+       unspecified or set to "auto", an appropriate value is
+       computed based on the approximate number of packed objects
+       in your repository, which hopefully is enough for
+       abbreviated object names to stay unique for some time.
 
 add.ignoreErrors::
 add.ignore-errors (deprecated)::