bug#42399: DejaGnu randomly truncates lines in runtest output

[Jacob Bachmeyer]

Andreas Schwab wrote:
> On Jul 16 2020, Alex Coplan wrote:
>   
> > Then, create a subdirectory bug.dg, containing a single file bug.exp
> > with the following contents:
> >
> >   global text
> >
> >   spawn "./a.out"
> >
> >   set prefix "\[^\r\n\]*"
> >   expect {
> >     -re "^$prefix\tPASSED:${text}*" {
> >     
>
> Are you sure you want to repeatedly match the last character in ${text}?
>   

That is what host_execute currently does in DejaGnu, since at least 2001 
to now.  The ${text} pattern fragment in lib/dejagnu.exp is a character 
class; I am considering replacing its use in host_execute and changing 
the {${text}*} in those patterns to {[^\n]+\n} which should fix this 
bug, but could have far-reaching effects on testsuites, which makes me 
somewhat reluctant to do so this close to a release.

This bug will be fixed in 1.6.4, but whether it will be fixed or a known 
bug in 1.6.3 is not yet determined.


-- Jacob