Description:
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I have PHP compiled as apache2handler SAPI and using ErrorDocument, which points to an PHP script. If this ErrorDocument is triggered, then apache child crashes.

It must be connected with the bug #33987
and as ironic it is, PHP 4.4.1 Changelog claims, that #33987  is fixed. Bug #33987 is actually reported against PHP5.1 and not against 4.4.0. PHP 4.4.0 works fine with ErrorDocuments.

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I looked into the apache2handler source (sapi/apache2handler/sapi_apache2.c) and after debugging it was clear, that crash happens on line (538):

   if (parent_req && strcmp(parent_req->handler, PHP_MAGIC_TYPE) && strcmp(parent_req->handler, PHP_SOURCE_MAGIC_TYPE) && strcmp(parent_req->handler, PHP_SCRIPT)) {

If changed to this:

   if (parent_req && parent_req->handler && strcmp(parent_req->handler, PHP_MAGIC_TYPE) && strcmp(parent_req->handler, PHP_SOURCE_MAGIC_TYPE) && strcmp(parent_req->handler, PHP_SCRIPT)) {

then everything's fine and works.

The correct extra check is present in 5.1.0 (but for some odd reason not in 4.4.1 and 5.0.5).

Reproduce code:
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.htaccess
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ErrorDocument 404 /error.php?status=404

/error.php
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die( "File Not Found!" );


Expected result:
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File Not Found!

Actual result:
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Apache2 crashes.