Values of 0 and undef treated the same

[pajlpajl]

The method get_shp_shx_header_value incorrectly returns undef instead of 0. Values of 0 are valid for coordinates and occur, say, at the Greenwich meridian. The line below is incorrect:
return $self->{'shx' . $val} || $self->{'shp_' . $val} || undef;
This line is correct:
return $self->{'shx_' . $val} // $self->{'shp_' . $val} // undef;
The line just a few lines above it
if (!($self->{'shx_' . $val} || $self->{'shp_' . $val})) {
will call $self->_read_shx_header() needlessly a second or more times and would also be improved using defined().

I did not review whether anything similar occurs elsewhere in the code.

[shawnlaffan]

Thanks for reporting.

As with #22, a pull request with a test would be appreciated.

In terms of the defined-or operator, we currently support 5.8. That said, bumping the minimum perl to 5.10 is an open issue (see #2).

At the very least the trailing || undef could be removed as it is redundant.

[pajlpajl]

If you just remove the trailing undef, it may still be incorrect. return $self->{'shx_' . $val} || $self->{'shp_' . $val}; You may have $self->{'shx_' . $val} validly set to zero, and if $self->{'shp_' . $val} is not defined, you will get undef returned. And if you exchange shx <-> shp you get 0 returned. So the whole construct is not well-defined. The below would suffice I think: return defined($self->{'shx_' . $val}) ? $self->{'shx_' . $val} : $self->{'shp_' . $val} From: shawnlaffan <notifications@github.com> Sent: Sunday, February 10, 2019 5:05 PM To: shawnlaffan/Geo-ShapeFile <Geo-ShapeFile@noreply.github.com> Cc: Dr. Peter A. J. Liggatt <pliggatt@microdecisions.com>; Author <author@noreply.github.com> Subject: Re: [shawnlaffan/Geo-ShapeFile] Values of 0 and undef treated the same (#23) Thanks for reporting. As with #22<#22>, a pull request with a test would be appreciated. In terms of the defined-or operator, we currently support 5.8. That said, bumping the minimum perl to 5.10 is an open issue (see #2<#2>). At the very least the trailing || undef could be removed as it is redundant. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#23 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AQsLifWXLcpgBmnMGIPKWu76A_zYy8G5ks5vMJeWgaJpZM4azKds>.

[shawnlaffan]

[update - fixed incorrect cpan syntax]

A dev release is now on CPAN at https://metacpan.org/release/SLAFFAN/Geo-ShapeFile-2.65_001

Could you please test if this works? If it does, and cpan testers stays green, then I will upload a new version.

You might already know this, but you can test it locally without installing it using these steps (updating path separators as needed for your OS):

cpanm --look Geo::ShapeFile@2.65_001
perl Makefile.PL
gmake
gmake test

perl -Mblib \path\to\your_perl_script_or_app.pl

You can also call it from some other path using

perl -Mblib=\path\to\geo_shapefile_build_dir\blib your_perl_script_or_app.pl

Or you can just add the blib\lib and blib\auto folders to the PERL5LIB env var.

[pajlpajl]

This works for me now, thank you. However, this edit at line 426: if (!defined ($self->{'shx_' . $val} || $self->{'shp_' . $val})) { may still not do what you want. For instance: perl -e 'if (!defined( 0 || undef)) {print "Got here\n"}' prints “Got here”, and if either value is 0, you do not need the if clause to execute. if (!defined ($self->{'shx_' . $val}) && !defined($self->{'shp_' . $val})) { or unless (defined ($self->{'shx_' . $val}) || defined($self->{'shp_' . $val})) { may be what you need. From: shawnlaffan <notifications@github.com> Sent: Sunday, February 10, 2019 6:03 PM To: shawnlaffan/Geo-ShapeFile <Geo-ShapeFile@noreply.github.com> Cc: Dr. Peter A. J. Liggatt <pliggatt@microdecisions.com>; Author <author@noreply.github.com> Subject: Re: [shawnlaffan/Geo-ShapeFile] Values of 0 and undef treated the same (#23) A dev release is now on CPAN at https://metacpan.org/release/SLAFFAN/Geo-ShapeFile-2.65_001 Could you please test if this works? If it does, and cpan testers stays green, then I will upload a new version. You might already know this, but you can test it locally without installing it using these steps (updating path separators as needed for your OS): cpanm --look Geo::ShapeFile::2.65_001 perl Makefile.PL gmake gmake test perl -Mblib \path\to\your_perl_script_or_app.pl You can also call it from some other path using perl -Mblib=\path\to\geo_shapefile_build_dir\blib your_perl_script_or_app.pl Or you can just add the blib\lib and blib\auto folders to the PERL5LIB env var. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#23 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AQsLiXOOFanlKIAqZS_v3MlBeDBJ5fIcks5vMKU7gaJpZM4azKds>.

[shawnlaffan]

version 2.66 is now on cpan: https://metacpan.org/release/SLAFFAN/Geo-ShapeFile-2.66

[shawnlaffan]

Marking as fixed.