reads either one <commit> or a list of <commit>
separated with a single space from its standard input.
+
-When a single commit is given on one line of such input, it compares
-the commit with its parents. The following flags further affects its
-behavior. The remaining commits, when given, are used as if they are
+When a single commit is given, it compares the commit with its
+parents. The remaining commits, when given, are used as if they are
parents of the first commit.
++
+The ID of the first (or only) commit, followed by a newline, is
+printed before the differences.
++
+The following flags further affects its behavior.
-m::
By default, 'git-diff-tree --stdin' does not show