Re: [Nmh-workers] nmh-1.7-RC1: scan with complex subjects dumps core

[Ralph Corderoy]

Hi Leonardo,

> Sure! Here what I see with your patch applied:
>
>  % scan -format '%(decode{subject})' +. 1
>  mbtowc(0x20) = 1
>  cntrl:0  space:1  blank:1  print:1
>  mbtowc(0x1f576) = 4
>  cntrl:0  space:0  blank:0  print:0
>  wcwidth(0x1f576) = -1

Yeah, I think the code was assuming if it's not cntrl, and not space,
then it must be print and therefore width >= 0.  But that's clearly not
true, even here, where Norm's sunglasses don't have a negative width,
e.g. U+0378.

    $ test/getcwidth --ctype | grep -m1 ' -1  [^cs]*$'
       378  -1  ------------
    $

That does mean I can reproduce the failed assertion using that rune.

    $ uip/scan -format '%(lit £)' .
    £
    $ uip/scan -format '%(lit ͸)' .
    scan: sbr/fmt_scan.c:280: cpstripped: Assertion `w >= 0' failed.

Sunglasses have a width of 1 here, that's why David and I don't see the
problem.

    $ test/getcwidth --ctype | grep 1f576
     1f576   1  address@hidden
    $

I've re-written the MULTIBYTE_ENABLED cpstripped() on git's master
branch, not the 1.7 one.  Could you give it a go with what failed
before, and ideally run a `make check' and if all's well a
`NMH_VALGRIND=1 VALGRIND_ME=1 make check' to give it a work out, it
takes a while, with your different definitions of Unicode widths.
docs/README.developers explains those two variables.

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy