Description:
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If a Library call does not return within 2s after the max_execution_time has been exceeded, zend_timeout_handler() in Zend/zend_execute_API.c approx. Line 1201 emits the error message to STDERR instead of writing it into the error_log and then kills the child. As a result, the following message, without any further explanation, is logged in error_log:

child 23444 exited with code 1 after 360.705768 seconds from start

If catch_workers_output is enabled, the "Maximum execution [...] exceeded" message is logged in error_log, prefixed with "said into stderr".

This is a regression from PHP 7.0. (tested with 7.0.15, which logs a message in error_log, while 7.1.1 does not with the default configuration).

Test script:
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<?php
/* generate an image with lots of colors using imagemagick:
convert -size 4096x4096 -define gradient:direction=east gradient:red-green PNG48:hor_gradient.png
convert hor_gradient.png -rotate 90 gradient_h.png
convert -size 4096x4096 gradient: PNG48:linear_gradient.png
composite linear_gradient.png -compose Multiply gradient_h.png grad.png

or download from http://can avan.de/lots_of_colors.png
*/

$i = new imagick();
$i->readimage('grad.png');
print($i->getImageColors()."\n");


Expected result:
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"Fatal error: Maximum execution time of 30+2 seconds" should be logged in the configured error_log, just like the "Fatal error: Maximum execution time of 30 seconds" message. 

This should be independent of the catch_workers_output setting.

Actual result:
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Only "child 1903 exited with code 1 after 68.983009 seconds from start" is logged.