do not write null sha1s to on-disk index

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 9f7cba2be6a97cb85072d22b3317d37d1afe80bf..ba7cd13483194399762b0f48e218ddb4011dfcf1 100644 (file)
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -52,6 +52,9 @@ endif::git-format-patch[]
 --patience::
        Generate a diff using the "patience diff" algorithm.
 
+--histogram::
+       Generate a diff using the "histogram diff" algorithm.
+
 --stat[=<width>[,<name-width>[,<count>]]]::
        Generate a diffstat.  You can override the default
        output width for 80-column terminal by `--stat=<width>`.