[htmltmpl] H::T bug

[Mathew R. <mat...@re...>]

Hi Sam and others,

One problem I have encountered frequently enough to be annoying (but not =
enough to do anything about) was that ocassionally the line numbers of a =
TMPL error, didn't match up with the line that the error occurred on.  =
As a result of my work on making H::T support custom TMPL_xxxx tag =
definitions, I came across this bug as it become rather blatent, and =
thus have found the solution for it.

On line 2259/2260 H::T implements:

    pop(@fstack), (*fname, *fcounter, *fmax) =3D \ ( =
@{$fstack[$#fstack]} )
      if ($fcounter > $fmax);

The implementation of TMPL_INCLUDE essentially inserts the included =
files' text at the current point of the statement, thus any text after =
the TMPL_INCLUDE (before the next 'chunk'), is essentially appended to =
the end of the included text.=20

This code suffers the problem that if a TMPL_INCLUDE is referenced near =
the end of a template file, then it doesn't correctly unroll the =
@fstack, thus it:
- incorrectly handles the end of the previous file -> as the previous =
file ends up with the wrong line number
- doesn't unroll more than one included file (thus each previous file =
will also end up with the wrong line number, as well)
- it is possible to hit a max include limit (ie TMPL_INCLUDE's > =
max_includes), due to the mis-handling of the end of the included =
template file(s).

The solution to this is to take into account the number of '\n's =
introduced by the appending of the text before the next chunk.  The code =
should read:

    while ($fcounter > $fmax) {
      my $counter_offset =3D $fcounter - $fmax;
      pop(@fstack), (*fname, *fcounter, *fmax) =3D \ ( =
@{$fstack[$#fstack]} );
      $fcounter +=3D $counter_offset;
    }


cheers,
Mathew


PS.  I was able to find this error by adding a support to H::T for an =
'includes_debug' option (ie. I added this option and the following code =
around line 2208).  Which if set, the following code gets executed:

          if ($options->{includes_debug}) {
            require 'Data/Dumper.pm';
            print STDERR "TMPL_INCLUDE stack: ", =
Data::Dumper::Dumper(\@fstack);
          }

ie: I think this would be a useful addition to compliment the existing =
debug options.