Current and previous versions of ISO/IEC 9945-1 (POSIX), particularly SUSv3
(2001) and SUSv4 (2008), require strfmon() to return rather meaningless
strings when used with the POSIX "C" locale. In particular, the standard
POSIX locale does not define a currency symbol, a monetary radix symbol
(decimal point) or a negative sign. This means strfmon(..., "%n", -123.45)
is supposed to produce "12345" instead of something like "$-123.45"!
The new xstrfmon() overcomes these limitations by using snprintf() as
appropriate.
This makes the main source code look a little cleaner, at the expense of
background magic happening in the configure-generated config.h. But this
magic was already happening for _GNU_SOURCE, __EXTENSIONS__ and the like.
The only wrinkle is that newer versions of NcursesW cause ./configure to
include "-D_XOPEN_SOURCE=600" as part of the compilation command line--on
systems that support _XOPEN_SOURCE=700. The AC_DEFINE/AC_DEFINE_UNQUOTED
macros automatically comment out any "#undef" lines in config.h, so the
file lib/xopen_source.h works around this limitation. It is
automatically included by config.h.
The Minix C library does not seem to support Unicode well (for example,
wcwidth() returns -1 for UTF-8 byte sequences), the native curses library
is quite buggy, playing around with the Gnulib wcwidth module did not fix
issues with Unicode--it's all in the "too hard" basket!
Note that although Star Traders compiles and installs successfully,
running the binary with a locale set to use non-ASCII strings currently
fails with "mkchstr: 'STRING': Illegal byte sequence" ("STRING" being the
translated string).
Rewrite a check that unscramble_table[] is of the right size as an
assertion, which prevents Clang from issuing a warning that the "result
of comparison of constant 256 with expression of type 'const unsigned
char' is always false".
Oh for the day that C11's _Static_assert can be used amongst all
compilers! But perhaps Gnulib's assert-h module can be used instead...
This version of the AX_CFLAGS_WARN_ALL macro uses a far more robust
method of detecting compilers to select appropriate warning flags. It
also uses the AX_PREPEND_FLAG macro instead of AX_APPEND_FLAG.
This version of ax_cflags_warn_all.m4 (and ax_prepend_flag.m4) has been
submitted upstream; see https://savannah.gnu.org/patch/?9673 for details.
The function wctob() returns an int that can be -1; a conversion to
unsigned char will make that value 0xFF. Although the "if" statement
still works in this case, we should be more diligent in our programming.
Arithmetic on void * pointers is undefined, according to Section 6.5.6
Paragraph 2, Section 6.2.5 Paragraph 1 and Section 6.2.5 Paragraph 19 of
the ISO/IEC 9899:1999 C99 standard: the void type is incomplete and thus
its size cannot be determined.
GCC allows pointer arithmetic on void * as an extension (and only warns
if "-Wpointer-arith" is given); the Oracle Developer Studio C compiler
issues a warning by default.
Newer versions of libncurses/libncursesw "#define _XOPEN_SOURCE 600" in
their pkg-config file. This change forces _XOPEN_SOURCE to be redefined
to 700 in that case.
The latest versions of the GNU Compiler Collection complain about signed
and unsigned integer comparisons when run with the "-Wextra" flag. Keep
those compilers happy.
Previous versions of the GNU Portability Library, and versions of the GNU
C Library as released with various Linux distributions, used strings no
longer present in the current version of the GNU Portability Library.
When used on systems with those strings, Star Traders could not provide
appropriate translations. This patch fixes that problem.
If Native Language Support is disabled, the program does not use the GNU
Gettext library and thus all strings are in ASCII format: enhanced Curses
is not needed in such situations.
In particular, mention the Clang LLVM compiler, require POSIX.1-2008
instead of POSIX.1-2001, and require libiconv if the GNU Gettext library
requires it.
