- This form is to view the changes between two <commit>,
- for example, tips of two branches.
+ This is to view the changes between two arbitrary
+ <commit>.
+
+'git-diff' [--options] <commit>..<commit> [--] [<path>...]::
+
+ This is synonymous to the previous form. If <commit> on
+ one side is omitted, it will have the same effect as
+ using HEAD instead.
+
+'git-diff' [--options] <commit>...<commit> [--] [<path>...]::
+
+ This form is to view the changes on the branch containing
+ and up to the second <commit>, starting at a common ancestor
+ of both <commit>. "git-diff A...B" is equivalent to
+ "git-diff $(git-merge-base A B) B". You can omit any one
+ of <commit>, which has the same effect as using HEAD instead.