Undefined index <index> in bootstrap.inc lines 335, 85, 92

Undefined index Notices in /includes/bootstrap.inc when cache is enabled. Several people seem to notice this after installing taxonomy_cache, but I'm not sure how that would be related.

Proximate cause is that bootstrap.inc often assumes a value of 'false' for uninitialized variables, so with error_reporting set to E_ALL, this throws notices and warnings. Given how high bootstrap.inc is in the script, this leads to fatal "Headers already sent" errors.

Root problem is that the static $files array is being used before it gets assigned a value.

Here is a manual "diff" (it's not real diff output, I just wrote it down as I edited) of code that makes the problem go away, but since I'm just a couple days into using Drupal, I'm not sure whether this should be getting caught further upstream. In any case, this makes my install run without errors, warnings or notices:

line 85
<<   if (!$files[$type]) {
>>   if (empty($files[$type])) {


line 92
<<   elseif ($files[$type][$name]) {
>>   elseif (!empty($files[$type][$name])) {

line 335
>>  if (!empty($files[$type][$name])) {
<<  if ($files[$type][$name]) {

There is discussion of this issue in

http://drupal.org/node/14457