Documentation: Describe other situations where -z affects git diff

diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index b3605c0ec560025e2b53286e4f69bc75c894140b..60fa684b1d99d798d8db4a1b0e89cd878f48c21a 100644 (file)
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -63,7 +63,9 @@ way to clean up all obsolete remote-tracking branches.
 OPTIONS
 -------
 -d::
-       Delete a branch. The branch must be fully merged in HEAD.
+       Delete a branch. The branch must be fully merged in its
+       upstream branch, or in `HEAD` if no upstream was set with
+       `--track` or `--set-upstream`.
 
 -D::
        Delete a branch irrespective of its merged status.