bug#50733: 28.0.1; project-find-regexp can block Emacs for a long time

[Gregory Heytings]

> > > Look closer at those matches which gid "missed", and you will see why 
> > > it didn't show them to you.
> >
> > I looked close (before you asked), and no, I don't see why some matches 
> > are not included.  For example it returns
> >
> > lib/tempname.c:212: __GT_FILE: create the file using open(O_CREAT|O_EXCL)
> >
> > but not
> >
> > lib/tempname.h:47: GT_FILE: create a large file using open(O_CREAT|O_EXCL)
> >
> > and it returns
> >
> > lib/open.c:99: /* Fail if one of O_CREAT, O_WRONLY, O_RDWR is specified and the 
> > filename
> >
> > but not
> >
> > lisp/gnus/nnmaildir.el:387: ;; If Emacs had O_CREAT|O_EXCL, we could return 
> > number-open here.
>
> Hint: they are all in comments.

Hint: read again, and look closer.  gid returns some matches in comments, 
some not.  For no apparent reason.