ping
Am 09.02.2016 um 16:51 schrieb Simon Reinhardt:
> Hi,
>
> Argp provides line wrapping of help and usage output. For this it
> maintains a buffer in the struct argp_fmtstream_t. During line breaking
> the buffer's contents grow due to the inserted spaces needed to indent
> the lines (function __argp_fmtstream_update in lib/argp-fmtstream.c).
> This breaks once the buffer is full and produces malformatted output.
> Example program:
>
> #include <config.h>
> #include <argp.h>
>
> static struct argp_option options[] = {
> {"test", 't', 0, 0, "1\n2\n3\n4\n5\n6"},
> {0}
> };
>
> static struct argp argp = {options};
>
> int
> main (int argc, char **argv)
> {
> argp_parse(&argp, argc, argv, 0, 0, 0);
> return 0;
> }
>
> This gives
> $ ./report --help
> Usage: report [OPTION...]
>
> -t, --test 1
> 2
> 3
> 4
> 5
> 6
> -?, --help give this help list
> --usage give a short usage message
>
> The indentation that should prefix the '6' erroneously prefixes the
> 'Usage' line.
>
> The suggested fix to __argp_fmtstream_update works by making it flush
> everything ASAP. This way no formatting of content inside the buffer is
> needed.
>
> This passes the existing tests (test-argp.c, test-argp-2.sh). In
> addition it produces identical --help and --usage output for GNU tar's
> large option table (see attached file tar.c).
>
> Further Nitpicking:
>
> before overlong words that exceed the line length one gets a spurious
> newline before the word:
>
> static struct argp_option options[] = {
> {"x", 'x', 0, 0,
> "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
> "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"},
> {0}
> };
>
> will produce the --help output
> Usage: bigword [OPTION...]
>
> -x, --x
> xxxxxxx(...)
> -?, --help give this help list
> --usage give a short usage message
>
> This is fixed by flushing at the end of indent_to in argp-help.c
>
> Cheers,
> Simon
>
