comment on

My suspicion is...

If you get a credit on the account, such that either $tcount, $tcash, or one of the others reach zero, you won't trigger the last, and will fall through to an inadvertant (and incorrect) change to $tcredit.

and the rewritten code doesn't suffer the same fate because

it doesn't have the possibility of falling through into a $tcredit update.

That's white type above. Select it to see it.

In reply to Re: Pop quiz: find the bug by dws
in thread Pop quiz: find the bug by Ovid

Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
Want more info? How to link or How to display code and escape characters are good places to start.


Do you know where your variables are?
	PerlMonks