MFC r312404, r312519, r313277:

Use S_ISREG instead of manual & (also it's better to compare the
result from & and the pattern instead of just assuming it's one bit
value).

Pointed out by Tianjie Mao <tjmao tjmao com>.

MFC r277802, r277811:

sed: Fix resource leak and dereference after NULL.

process.c:
Protect access against NULL.

main.c:
Prevent outfile overwrite resource leak.

CID: 271181
CID: 1006930

Obtained from: NetBSD

MFC r268193, r268203:

Fix sed(1) usage: the -i extension is not an optional.

MFC r267692, r267703:
Add -u (unbuffered output) after GNU sed.

Obtained from: NetBSD

MFC r277802, r277811:

sed: Fix resource leak and dereference after NULL.

process.c:
Protect access against NULL.

main.c:
Prevent outfile overwrite resource leak.

CID: 271181
CID: 1006930

Obtained from: NetBSD

MFC r268193, r268203:

Fix sed(1) usage: the -i extension is not an optional.

MFC r267692, r267703:
Add -u (unbuffered output) after GNU sed.

Obtained from: NetBSD