The code assumed that printing numbers with thousand separators
and decimal points would always produce only US-ASCII characters.
This was used for buffer sizes (with snprintf(), no overflows)
and aligning columns of the progress indicator and --list. That
assumption was wrong (e.g. LC_ALL=fi_FI.UTF-8 with glibc), so
multibyte character support was added in this commit. The old
way is used if the operating system doesn't have enough multibyte
support (e.g. lacks wcwidth()).
The sizes of buffers were increased to accomodate multibyte
characters. I don't know how big they should be exactly, but
they aren't used for anything critical, so it's not too bad.
If they still aren't big enough, I hopefully get a bug report.
snprintf() takes care of avoiding buffer overflows.
Some static buffers were replaced with buffers allocated on
stack. double_to_str() was removed. uint64_to_str() and
uint64_to_nicestr() now share the static buffer and test
for thousand separator support.
Integrity check names "None" and "Unknown-N" (2 <= N <= 15)
were marked to be translated. I had forgot these, plus they
wouldn't have worked correctly anyway before this commit,
because printing tables with multibyte strings didn't work.
Thanks to Marek Černocký for reporting the bug about
misaligned table columns in --list output.
Originally both base-2 and base-10 were supported, but since
there seems to be little need for base-10 in XZ Utils, treat
everything as base-2 and also be more relaxed about the case
of the first letter of the suffix. Now xz will accept e.g.
KiB, Ki, k, K, kB, and KB, and interpret them all as 1024. The
recommended spelling of the suffixes are still KiB, MiB, and GiB.
Seems that in addition on Windows and DOS, also OpenBSD
lacks support for %'d style printf() format strings.
So far that is the only modern POSIX-like system I know
with this problem, but after this hack, the thousand
separator shouldn't be a problem on any system.
Maybe testing if a format string like %'d produces
reasonable output is invoking undefined behavior on some
systems, but so far all the problematic systems I've tried
just print the raw format string (e.g. %'d prints 'd).
Maybe Autoconf test would have been better, but this
hack works also for cross-compilation, and avoids
recompilation in case the system libc starts to support
the thousand separator.
Don't round the memory usage limit in xzdec --help to avoid
an integer overflow and to not give wrong impression that
the limit is high enough when it may not actually be.
