When system calls indicate an error they return -1, not some arbitrary
value < 0. errno is only updated in this case. Change all (most?)
callers of syscalls to follow this better, and let's see if this strictness
helps us in the future.

Quiet compiler warnings; as applied to usr.bin/cvs by millert@

ok millert@

Convert xfree to free. From Fritjof Bornebusch. ok deraadt

Replace <sys/param.h> with <limits.h> and other less dirty headers where
possible. Annotate <sys/param.h> lines with their current reasons. Switch
to PATH_MAX, NGROUPS_MAX, HOST_NAME_MAX+1, LOGIN_NAME_MAX, etc. Change
MIN() and MAX() to local definitions of MINIMUM() and MAXIMUM() where
sensible to avoid pulling in the pollution. These are the files confirmed
through binary verification.
ok guenther, millert, doug (helped with the verification protocol)

An internal function called xrealloc() is actually a fail-hard
reallocarray()... so rename it.

Zap some stored values never read; From Fritjof Bornebusch; ok nicm@

Switch rcsdiff(1) binary file detection from !(isprint() || isspace()) to
checking for embedded NULs, as was done for grep(1) and diff(1) some time ago.
Avoids problems with e.g. latin1-encoded files being treated as binary, since
isprint() uses only ASCII by default and rcsdiff(1) doesn't call setlocale().
ok sthen

Remove some unneeded includes and dead code, from Michael W Bombardieri.

ok jasper xsa

Move an isqrt() call outside a macro, from Michael W Bombardieri.

ok ray

Reduce variable/function name and whitespace differences between
cvs/rcs.

OK xsa zinovik

Combine two diff_output lines into one, from diff.

OK stsp xsa nicm

Die immediately if pread fails. It's a fatal error so treat it as
such. Besides, we weren't handling the NULL being returned.

From diff. Minor nit by nicm.

OK xsa stsp nicm

Use warnx instead of warn since errno wasn't set. From diff.

OK xsa stsp nicm

Sync with diff/diffreg.c r1.75:
Return -1 on error as advertised.
Handle case when only one stream failed.

OK xsa, stsp

More cvs/diff/rcs convergence:
1. Mostly variable/function renaming, SIZE_T_MAX->SIZE_MAX, and
spacing.
2. One strchr -> strncspn.
3. diff had a weird thing where it set file[12] = ofile[12] but
never updated file or ofile, then if file and ofile were different
it freed it. I removed it.

OK millert

use strcspn to properly overwrite '\n' in fgets returned buffer

ok pyr@, ray@, millert@, moritz@, chl@

Rename rcs_diffreg() to diffreg().

OK joris@

Sync cvs/rcs diff code.

OK joris and xsa.

diff(1) sync, mostly spacing and moving crap around, except:
- stone() and newcand() cannot return < 0, so don't check it.
- \r, \v, \f are also whitespace

OK joris

Some syncs with diff(1):
- prepare() only returns 0, so change it to void and remove code
that checks its return value.
- Rename diff_len[] to len[].
- Remove casts that made the code a no-op:
(size_t)filesize <= SIZE_MAX

OK xsa

Remove cand structure (but not its definition).

Remove unused struct diff_arg.

Get rid of another useless variable, another difference between our
diff code and diff(1).

OK niallo@

Since xrealloc dies on failure it is safe to directly assign to the
original pointer. Theo agrees, and so does the rest of the tree
(ssh, etc. all do this already).

Saves a bunch of variables and assignments.

OK niallo@

Some spacing syncs with diff(1).

"in formation" -> "information"

OK niallo@

Line up comments with the rest of the file, like in diff(1).

sync with espie@'s latest change to diff(1).

from src/usr.bin/diff/diffreg.c rev 1.67:

improve -p for C++ code: classes definition often have
public:/protected:/private: at the start of line.
This lets the -p scanner just take note of the section and keep
looking for the actual class definition.

Also increase function name bufsize so it shows most of these pesky C++
decls...

OK niallo@ espie@.

As done in OpenCVS, general includes cleanup sweep. OK otto@.

Fix const inconsistencies, void pointer artithmetic;
Based on diff from otto@ in OpenCVS. OK otto@.

Plug memory leak.

OK niallo@.

Add support to rcsdiff for all the other diff flags that
are pertinent to files (not directories) and that do not
conflict with rcsdiff-specific flags. OK xsa@

files_differ() should return -1 on error, according to comments. Make
it so.

Add checks for all return values.

``put it in'' xsa@

spacing

Use fstat instead of stat, simplifie switch statement into if
statement, and remove __inline.

OK xsa@

Remove (size_t) casts on integer constants.

We should not cover up lint's shortcomings, especially if they no
longer exist.

``This is definately good.'' niallo@.

- fix rcsdiff exit status on success/errors; now matches gnu/usr.bin/rcs.
- add DIAGNOSTICS section to rcsdiff.1 wrt exit codes.
ok ray@ and jmc@ for man page bits.

Check return values for all strlcpy, and strlcat calls.

OK xsa@ and probably others.

err() cleanup;

fork our code we shared between openrcs/cvs into the openrcs dir.

this was starting to become inhuman to maintain without
ugly ugly hacks in the shared code, and it will be easier
to make specific changes for openrcs without touching the
soon-to-be-replaced opencvs code.

Quiet compiler warnings; as applied to usr.bin/cvs by millert@

ok millert@

Convert xfree to free. From Fritjof Bornebusch. ok deraadt

Replace <sys/param.h> with <limits.h> and other less dirty headers where
possible. Annotate <sys/param.h> lines with their current reasons. Switch
to PATH_MAX, NGROUPS_MAX, HOST_NAME_MAX+1, LOGIN_NAME_MAX, etc. Change
MIN() and MAX() to local definitions of MINIMUM() and MAXIMUM() where
sensible to avoid pulling in the pollution. These are the files confirmed
through binary verification.
ok guenther, millert, doug (helped with the verification protocol)

An internal function called xrealloc() is actually a fail-hard
reallocarray()... so rename it.

Zap some stored values never read; From Fritjof Bornebusch; ok nicm@

Switch rcsdiff(1) binary file detection from !(isprint() || isspace()) to
checking for embedded NULs, as was done for grep(1) and diff(1) some time ago.
Avoids problems with e.g. latin1-encoded files being treated as binary, since
isprint() uses only ASCII by default and rcsdiff(1) doesn't call setlocale().
ok sthen

Remove some unneeded includes and dead code, from Michael W Bombardieri.

ok jasper xsa

Move an isqrt() call outside a macro, from Michael W Bombardieri.

ok ray

Reduce variable/function name and whitespace differences between
cvs/rcs.

OK xsa zinovik

Combine two diff_output lines into one, from diff.

OK stsp xsa nicm

Die immediately if pread fails. It's a fatal error so treat it as
such. Besides, we weren't handling the NULL being returned.

From diff. Minor nit by nicm.

OK xsa stsp nicm

Use warnx instead of warn since errno wasn't set. From diff.

OK xsa stsp nicm

Sync with diff/diffreg.c r1.75:
Return -1 on error as advertised.
Handle case when only one stream failed.

OK xsa, stsp

More cvs/diff/rcs convergence:
1. Mostly variable/function renaming, SIZE_T_MAX->SIZE_MAX, and
spacing.
2. One strchr -> strncspn.
3. diff had a weird thing where it set file[12] = ofile[12] but
never updated file or ofile, then if file and ofile were different
it freed it. I removed it.

OK millert

use strcspn to properly overwrite '\n' in fgets returned buffer

ok pyr@, ray@, millert@, moritz@, chl@

Rename rcs_diffreg() to diffreg().

OK joris@

Sync cvs/rcs diff code.

OK joris and xsa.

diff(1) sync, mostly spacing and moving crap around, except:
- stone() and newcand() cannot return < 0, so don't check it.
- \r, \v, \f are also whitespace

OK joris

Some syncs with diff(1):
- prepare() only returns 0, so change it to void and remove code
that checks its return value.
- Rename diff_len[] to len[].
- Remove casts that made the code a no-op:
(size_t)filesize <= SIZE_MAX

OK xsa

Remove cand structure (but not its definition).

Remove unused struct diff_arg.

Get rid of another useless variable, another difference between our
diff code and diff(1).

OK niallo@

Since xrealloc dies on failure it is safe to directly assign to the
original pointer. Theo agrees, and so does the rest of the tree
(ssh, etc. all do this already).

Saves a bunch of variables and assignments.

OK niallo@

Some spacing syncs with diff(1).

"in formation" -> "information"

OK niallo@

Line up comments with the rest of the file, like in diff(1).

sync with espie@'s latest change to diff(1).

from src/usr.bin/diff/diffreg.c rev 1.67:

improve -p for C++ code: classes definition often have
public:/protected:/private: at the start of line.
This lets the -p scanner just take note of the section and keep
looking for the actual class definition.

Also increase function name bufsize so it shows most of these pesky C++
decls...

OK niallo@ espie@.

As done in OpenCVS, general includes cleanup sweep. OK otto@.

Fix const inconsistencies, void pointer artithmetic;
Based on diff from otto@ in OpenCVS. OK otto@.

Plug memory leak.

OK niallo@.

Add support to rcsdiff for all the other diff flags that
are pertinent to files (not directories) and that do not
conflict with rcsdiff-specific flags. OK xsa@

files_differ() should return -1 on error, according to comments. Make
it so.

Add checks for all return values.

``put it in'' xsa@

spacing

Use fstat instead of stat, simplifie switch statement into if
statement, and remove __inline.

OK xsa@

Remove (size_t) casts on integer constants.

We should not cover up lint's shortcomings, especially if they no
longer exist.

``This is definately good.'' niallo@.

- fix rcsdiff exit status on success/errors; now matches gnu/usr.bin/rcs.
- add DIAGNOSTICS section to rcsdiff.1 wrt exit codes.
ok ray@ and jmc@ for man page bits.

Check return values for all strlcpy, and strlcat calls.

OK xsa@ and probably others.

err() cleanup;

fork our code we shared between openrcs/cvs into the openrcs dir.

this was starting to become inhuman to maintain without
ugly ugly hacks in the shared code, and it will be easier
to make specific changes for openrcs without touching the
soon-to-be-replaced opencvs code.