Re: [XeTeX] ifcat changed?

2017-04-16 Thread Apostolos Syropoulos
>Definitely a bug. The TeXbook defines the behaviour of \if and \ifcat, >and all control sequences are considered to have character code 256 >and category code 16, unless \let equal to a non-active character, in >which case they have the value of that character. After comparing the relevant code

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Zdenek Wagner
2017-04-16 10:08 GMT+02:00 Julian Bradfield : > On 2017-04-15, Bruno Le Floch wrote: > > The primitive conditional "\ifcat\relax\cr true\else false\fi" gives > > "true" in pdfTeX, LuaTeX, (e)(u)pTeX, and XeTeX from some time ago > > (could be

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Philip Taylor
Zdenek Wagner wrote: > Not all control sequences but primitives. Again, I would respectfully suggest that Knuth's own words are the best guidance here : > *\**if * > > TeX will expand macros following *\if* until two unexpandable tokens are > found. If either token is a control sequence,

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Julian Bradfield
On 2017-04-16, Zdenek Wagner wrote: > 2017-04-16 10:08 GMT+02:00 Julian Bradfield : >> Definitely a bug. The TeXbook defines the behaviour of \if and \ifcat, >> and all control sequences are considered to have character code 256 >> and

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Julian Bradfield
On 2017-04-15, Bruno Le Floch wrote: > The primitive conditional "\ifcat\relax\cr true\else false\fi" gives > "true" in pdfTeX, LuaTeX, (e)(u)pTeX, and XeTeX from some time ago > (could be years), but "false" in XeTeX 0.6 Definitely a bug. The TeXbook defines the

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Apostolos Syropoulos
>As far as I can tell from the sources, the bug likely was there from the >start, and only affects \span, \cr and \crcr.  Basically, their >character code is too small.  This can be fixed by changing >"special_char" from 65537 to 1114112 or so, to make the values of >"span_code", "cr_code",

Re: [XeTeX] ifcat changed?

2017-04-16 Thread Bruno Le Floch
Filed https://sourceforge.net/p/xetex/bugs/138/ with a text essentially identical to my message below explaining the bug's origin and how to fix it. On 04/16/2017 06:50 AM, Julian Bradfield wrote: > On 2017-04-16, Zdenek Wagner wrote: >> 2017-04-16 10:08 GMT+02:00 Julian