header stays after enter null tag

I changed isset($block->subject) to !empty($block->subject), which now checks to see if the variable is empty, rather than set. Apparently $block->subject is not set to NULL when leaving the block title blank or entering <none>, so isset($block->subject) still returns TRUE, even though it's empty.

I don't know if this is a bug or a feature, but I'll provide the patch, and here's the old and new code of the entire file:

Old block.tpl.php:

<div id="block-<?php print $block->module .'-'. $block->delta; ?>" class="block block-<?php print $block->module ?><?php print (isset($block->subject) ? ' block-title' : '') ?><?php print ($zebra ? ' block-'.$zebra : '') ?>">  
  <div class="blockinner">
    <?php if (isset($block->subject)): ?><h2 class="title"><?php print $block->subject; ?></h2><?php endif; ?>
    <div class="content">
      <?php print $block->content; ?>
    </div>    
  </div>
</div>

New block.tpl.php

<div id="block-<?php print $block->module .'-'. $block->delta; ?>" class="block block-<?php print $block->module ?><?php print (!empty($block->subject) ? ' block-title' : '') ?><?php print ($zebra ? ' block-'.$zebra : '') ?>">  
  <div class="blockinner">
    <?php if (!empty($block->subject)): ?><h2 class="title"><?php print $block->subject; ?></h2><?php endif; ?>
    <div class="content">
      <?php print $block->content; ?>
    </div>    
  </div>
</div>

Forgot to set to 'needs review'.

Patch works fine.

Duplicate of #172876: Block Titles bar shown even if block title empty