Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

patch(1): give /dev/null patches special treatment

We have a bad habit of duplicating contents of files that are sourced from
/dev/null and applied more than once... take the more sane (in most ways)
GNU route and complain if the file exists and offer reversal options.

This still falls short a little bit as selecting "don't reverse, apply
anyway" will still give you duplicated file contents. There's probably other
issues as well, but awareness is the first step to happiness.

MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D21535

Remove automatic checkout feature.

Obtained from: DragonFly via OpenBSD
Relnotes: yes
MFC: never

patch(1): small include changes.

Mostly to match OpenBSD, no functional change.

Obtained from: OpenBSD

Fixes to exit status.

Exit with EXIT_FAILURE for invalid arguments.
Fixes NetBSD-PR 43517.

Print version string to stdout instead of stderr;
it is user-requested and not an error.

Obtained from: NetBSD
MFC after: 5 days

patch: Bring in xstrdup and use it when appropriate.

The function savestr allows NULL return values during Plan A patching so in
case of out of memory conditions, Plan B can step in. In many cases, NULL
value is not properly handled, so use xstrdup here (it's outside Plan A/B
patching, which means that even Plan B relies on successful operations).

Clean up some whitespaces while here

Obtained from: OpenBSD
MFC after: 2 weeks

Improve bsdpatch usability:

- Ask only once for "Apply anyway". [1]
- Tell user what file have failed patch rather than just how
many hunks failed.

Reported by: jmg via pfg [1]
Tested by: pfg [1]
Approved by: re (gjb)

Fix file selection logic for the RCS/SCCS case, as was done for the simple
file case before. Bump version because of the changed behavior, which now
matches the documentation.

Reviewed by: pfg

Revert r250972 to fix build.

The error handling for writes to the target file could lead to the final
fclose() being skipped. Fix this by using boolean "&" and "|" instead of
short-cut operators "&&" and "||".
While here, increment the last part of the version string. The reason is
the fixed output file selection logic in pch.c, which was committed as
r250943, yesterday.

Reviewed by: pfg

patch: Follow original versioning convention.

According to the README file [1] the 12u variant, unlike
the 12g variant, contains no copyleft code. It is therefore
convenient to keep using the original versioning scheme to
prevent confusions.

[1] http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/patch/README

- Refresh code with latest OpenBSD revisions.
- Remove $DragonFly$ tags as they are using git nowadays and VCS tags will
not help merging.
- Other changes to Copyright headers to make them consistent with other
source code, we intend to fork from this point.

Reviewed by: pfg

- Add a BSD-licensed patch, ported by Pedro F. Giffuni (pfg) from
DragonflyBSD and install it as bsdpatch. WITH_BSD_PATCH makes it
default and installs GNU patch as gnupatch.

Submitted by: pfg
Obtained from: The DragonflyBSD Project

Import of a BSD-licensed version of `patch', which will eventually
replace the version we currently have in src/gnu/usr.bin/patch/.
Among other things, this version includes a --posix option for strict
POSIX conformance.

This version is the current source from OpenBSD as of today. It is
their 3.5-release, plus a few updates to patch.c and pch.c that they
made about three weeks ago.

kill the undead

Finish importing Lite2's src/usr.bin, except for ex, diff, grep, mail,
pascal and vmstat.sparc. All changed files on the vendor branch should
already have been imported.

This commit was generated by cvs2svn to compensate for changes in r13122,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Usr.bin Sources