Here's the sub that prints the debug message and appends the content: 
sub verbose_add_content {
  printf "depth: %d adding: ((%s))\n", $depth, $_[1];
  $_[0] .= $_[1]
}

[download]
As we can see, it prints $_[1] and appends $_[1]. Of course, the value of $_[1] should be exactly the same each time (barring a weird use of tied scalars).

So, my best guess is that something else is going on. Is it possible that the script you're editing and the script you're running are two different files? I've made that mistake a few times.

If the bug doesn't reveal itself soon, you may want to package up all the files involved, put them on the web, and post a link, so that other monks can download it and run the same test you're using.

In reply to Re: Recursive string building: stepwise and final strings differ by chipmunk
in thread Recursive string building: stepwise and final strings differ by princepawn

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.