Description:
------------
Hello,

I notice you about this bug that causes that PHP fails and 'Segmentation Fault' and so you can see "Error Gateway" in browser!!

Only happens with new released version PHP 7.1.0 and without execution code! just reading the file fpdf.php that I use to generate PDF files (http://www.fpdf.org) and in function "Image" in main class:


This code in the file and "without execution" causes segmentation fault when PHP only read the file:


	if($w<0)
		$w = -$info['w']*72/$w/$this->k;
	if($h<0)
		$h = -$info['h']*72/$h/$this->k;




To solve it... I have changed avoiding /$w and /$h because it's seem that PHP consider value as 0 or whatever


	if($w<0)
		$w = -$info['w']*72/min($w,1)/$this->k;
	if($h<0)
		$h = -$info['h']*72/min($h,1)/$this->k;


Thanks and happy new year from Spain ;)

Eduardo Ruiz

Test script:
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// Just create a file with these lines and without execution and read it:


	if($w<0)
		$w = -$info['w']*72/$w/$this->k;
	if($h<0)
		$h = -$info['h']*72/$h/$this->k;

Expected result:
----------------
No segmentation fault!!!

Actual result:
--------------
Segmentation Fault and Gateway error