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Entry tags:
the hazards of coding for webservers vs. shell scripts
When I was doing some code cleanup a few months ago, I saw some lines that looked like this:
I decided that looked redundant and changed it to:
Take my advice: don't combine "my" statements and postfix conditionals. Ever.
I've updated the programming guidelines to warn people away from this as well.
The manifestation of this particular bug was to cause the $foo variable to be referenced in global scope if the conditional was false. In that situation, the assigned value would persist across execution threads, such that if two people in a row had a true $baz, the second user would see the first user's value of $foo. Even with use warnings and use strict in effect, Perl apparently thinks this is perfectly fine.
ETA:![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
exor674 says this command will find it (but not in BML files):
my $foo;
$foo = $bar unless $baz;I decided that looked redundant and changed it to:
my $foo = $bar unless $baz;Take my advice: don't combine "my" statements and postfix conditionals. Ever.
I've updated the programming guidelines to warn people away from this as well.
The manifestation of this particular bug was to cause the $foo variable to be referenced in global scope if the conditional was false. In that situation, the assigned value would persist across execution threads, such that if two people in a row had a true $baz, the second user would see the first user's value of $foo. Even with use warnings and use strict in effect, Perl apparently thinks this is perfectly fine.
ETA:
exor674 says this command will find it (but not in BML files):perlcritic --single-policy ProhibitConditionalDeclarations