K 10
svn:author
V 6
kevans
K 8
svn:date
V 27
2020-10-27T12:27:26.458366Z
K 7
svn:log
V 363
diff: don't force the format to 'context' with -p immediately

Instead, leave the fomat as unspecified (if it hasn't been) and use the
-p flag as a hint to 'context' if no other formatting option is specified.

This fixes `diff -purw`, used frequently by emaste, and matches the behavior
of its GNU counterpart.

PR:		250015
Reviewed by:	emaste
MFC after:	1 week

END