Fix bug #73668

Not bothering to implement special handling to get an accurate
range for this case.

NEWS

@@ -2,10 +2,14 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? 2017, PHP 7.1.1
 
-- Opcache:
+- Core:
   . Fixed bug #73663 ("Invalid opcode 65/16/8" occurs with a variable created
     with list()). (Laruence)
+
+- Opcache:
   . Fixed bug #73654 (Segmentation fault in zend_call_function). (Nikita)
+  . Fixed bug #73668 ("SIGFPE Arithmetic exception" in opcache when divide by
+    minus 1). (Nikita)
 
 01 Dec 2016, PHP 7.1.0
 

ext/opcache/Optimizer/zend_inference.c

@@ -610,6 +610,10 @@ static int zend_inference_calc_binary_op_range(
 				if (op2_min <= 0 && op2_max >= 0) {
 					break;
 				}
+				if (op1_min == ZEND_LONG_MIN && op2_max == -1) {
+					/* Avoid ill-defined division, which may trigger SIGFPE. */
+					break;
+				}
 				t1 = op1_min / op2_min;
 				t2 = op1_min / op2_max;
 				t3 = op1_max / op2_min;

ext/opcache/tests/bug73668.phpt

@@ -0,0 +1,8 @@
+--TEST--
+Bug #73668: "SIGFPE Arithmetic exception" in opcache when divide by minus 1
+--FILE--
+<?php
+$a/-1;
+?>
+--EXPECTF--
+Notice: Undefined variable: a in %s on line %d