xxdiff and libxcb assertion

[Clausen, Jörn <joern.clausen%uni-bielefeld.de@localhost>]

I just managed to compile textproc/xxdiff on Solaris 11. The last time I 
had success with this was version 3.3.8 way back in 2012 on Solaris 10.

Unfortunately, the binary bails out immediately with

Assertion failed: XCB_SEQUENCE_COMPARE(request, <=, c->out.request), 
file ../../unpacked-src/src/xcb_out.c, line 373
Abort

when given two or three files or directories to compare ("xxdiff --help" 
works, for that matter...)

The assertion is triggered in libxcb, which is correctly taken from 
pkgsrc, not Solaris:

$ ldd /opt/pkg-hrz/20191004/bin/xxdiff | grep xcb
        libxcb.so.1 =>   /opt/pkg-hrz/20191004/lib/libxcb.so.1


This is the code that fails the assertion:

    assert(XCB_SEQUENCE_COMPARE(request, <=, c->out.request));
    if(XCB_SEQUENCE_COMPARE(c->out.request_written, >=, request))

Without understanding what's going on here: Is it okay that something 
about c->out.request is asserted and then c->out.request_written is 
used? This looks odd to me. A few lines down the code, this assertion is 
used:

    assert(XCB_SEQUENCE_COMPARE(c->out.request_written, >=, request));

Any enlightenment is appreciated :)

BTW: On NetBSD, xxdiff works as expected...

--
Jörn Clausen
Plattformen & Serverdienste
BITS - Bielefelder IT-Servicezentrum
https://www.uni-bielefeld.de/bits