t1510: fix typo in the comment of a test

diff --git a/Documentation/git-difftool.txt b/Documentation/git-difftool.txt
index 6fffbc7bf89d01b14505c03993de9d97d37e9404..db87f1d42382e32d7e3ee94e5c3d0a032b7430e2 100644 (file)
--- a/Documentation/git-difftool.txt
+++ b/Documentation/git-difftool.txt
@@ -56,14 +56,16 @@ the configured command line will be invoked with the following
 variables available: `$LOCAL` is set to the name of the temporary
 file containing the contents of the diff pre-image and `$REMOTE`
 is set to the name of the temporary file containing the contents
-of the diff post-image.  `$BASE` is provided for compatibility
-with custom merge tool commands and has the same value as `$LOCAL`.
+of the diff post-image.  `$MERGED` is the name of the file which is
+being compared. `$BASE` is provided for compatibility
+with custom merge tool commands and has the same value as `$MERGED`.
 
 -x <command>::
 --extcmd=<command>::
        Specify a custom command for viewing diffs.
        'git-difftool' ignores the configured defaults and runs
        `$command $LOCAL $REMOTE` when this option is specified.
+       Additionally, `$BASE` is set in the environment.
 
 -g::
 --gui::