Spurious $GLOBALS name attribute caused 404 with widgetized theme

I had modified my custom theme to add widgetized sidebars, but as soon as I added the appropriate code, I got a series of 404 errors. After many days of tracing through the code, I found that I’d picked up a spurious $GLOBALS[‘name’] variable of value “Search Sidebar” that was throwing off the SQL request to the DB.

Here’s what I found….

Through my tracing I could see that a $GLOBALS[‘name’] was being added into the DB query when I used the widgetized theme, which wasn’t there with the old theme.

By tracing the flow through all the modules called by wp-blog-header.php I could see that nothing was set in $GLOBALS[‘name’] before my custom functions.php. However after the functions call, it was set to “Search Sidebar”.

I put some tracing statements into the code to see what was going on:

<?php
/**
 * @package WordPress
 * @subpackage Kyoto-Green-3
 */
$sidebars = array('Home Sidebar',
                'Single Sidebar',
                'Page Sidebar',
                'List Sidebar',
                'Gallery Sidebar',
                'Library Sidebar',
                'Search Sidebar');
foreach($sidebars as $name) {
        $dae_error = ">>>> 9a. Name: " . $name . " global name: " . $GLOBALS['name'];
        error_log($dae_error, 0);
        register_sidebar(array('name' => $name,
                'before_widget' => '<div class="block">',
                'after_widget' => '</div><div class="blockfooter"></div>',
                'before_title' => '<h2>',
                'after_title' => '</h2>'));
        $dae_error = ">>>> 9b. Name: " . $name . " global name: " . $GLOBALS['name'];
        error_log($dae_error, 0);
};
?>

My php error log showed:

[20-Aug-2009 07:40:13] >>>> 6yb. In wp-settings; global name:
[20-Aug-2009 07:40:13] >>>> 6yc. In wp-settings; global name:
[20-Aug-2009 07:40:13] >>>> 6yd. In wp-settings; global name:
[20-Aug-2009 07:40:13] >>>> 9a. Name: Home Sidebar global name: Home Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Home Sidebar global name: Home Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: Single Sidebar global name: Single Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Single Sidebar global name: Single Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: Page Sidebar global name: Page Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Page Sidebar global name: Page Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: List Sidebar global name: List Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: List Sidebar global name: List Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: Gallery Sidebar global name: Gallery Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Gallery Sidebar global name: Gallery Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: Library Sidebar global name: Library Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Library Sidebar global name: Library Sidebar
[20-Aug-2009 07:40:13] >>>> 9a. Name: Search Sidebar global name: Search Sidebar
[20-Aug-2009 07:40:13] >>>> 9b. Name: Search Sidebar global name: Search Sidebar
[20-Aug-2009 07:40:13] >>>> 6yy. In wp-settings; global name: Search Sidebar
[20-Aug-2009 07:40:13] >>>> 6zz. In wp-settings; global name: Search Sidebar

So each iteration of the foreach loop was setting the $GLOBALS[‘name’] to the current $name value.

The fix was easy; I merely unset the variable at the bottom of the loop (I suppose I could have done it outside the loop):

<?php
/**
 * @package WordPress
 * @subpackage Kyoto-Green-3
 */
$sidebars = array('Home Sidebar',
                'Single Sidebar',
                'Page Sidebar',
                'List Sidebar',
                'Gallery Sidebar',
                'Library Sidebar',
                'Search Sidebar');
foreach($sidebars as $name) {
        register_sidebar(array('name' => $name,
                'before_widget' => '<div class="block">',
                'after_widget' => '</div><div class="blockfooter"></div>',
                'before_title' => '<h2>',
                'after_title' => '</h2>'));
        unset($GLOBALS['name']);
};
?>

I don’t know enough about how PHP processes variables and assigns GLOBAL variables, but this behaviour looks wrong to me.

Can anyone explain why this is happening and if there’s a better way to resolve the issue? Perhaps use other variable names that don’t clash with the wp_query ones?