the command line where an option is expected, the option parser
used just one byte of the unknown letter when reporting an error.
+ * In v1.8.1, the attribute parser was tightened too restrictive to
+ error out upon seeing an entry that begins with an ! (exclamation),
+ which may confuse users to expect a "negative match", which does
+ not exist. This has been demoted to a warning; such an entry is
+ still ignored.
+
* "git apply --summary" has been taught to make sure the similarity
value shown in its output is sensible, even when the input had a
bogus value.