Changes in behavior

The message that a binary file matches is now sent to standard error
and the message has been reworded from "Binary file FOO matches" to
"grep: FOO: binary file matches", to avoid confusion with ordinary
output or when file names contain spaces and the like, and to be
more consistent with other diagnostics. For example, commands
like 'grep PATTERN FILE | wc' no longer add 1 to the count of
matching text lines due to the presence of the message. Like other
stderr messages, the message is now omitted if the --no-messages
(-s) option is given.

Two other stderr messages now use the typical form too. They are
now "grep: FOO: warning: recursive directory loop" and "grep: FOO:
input file is also the output".

The --files-without-match (-L) option has reverted to its behavior
in grep 3.1 and earlier. That is, grep -L again succeeds when a
line is selected, not when a file is listed. The behavior in grep
3.2 through 3.4 was causing compatibility problems.