From: Nikita Popov <nikita.ppv@gmail.com>
Date: Sat, 22 Jul 2017 12:53:23 +0000 (+0200)
Subject: Fix block removal if there are duplicate successors
X-Git-Tag: php-7.2.0beta2~74
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=96665fbfe0d520035f672dc7919b541b288806ca;p=php

Fix block removal if there are duplicate successors
---

diff --git a/ext/opcache/Optimizer/zend_ssa.c b/ext/opcache/Optimizer/zend_ssa.c
index b0c087b1bd..a82d7ff225 100644
--- a/ext/opcache/Optimizer/zend_ssa.c
+++ b/ext/opcache/Optimizer/zend_ssa.c
@@ -1382,7 +1382,12 @@ void zend_ssa_remove_block(zend_op_array *op_array, zend_ssa *ssa, int i) /* {{{
 				break;
 			}
 		}
-		ZEND_ASSERT(pred_offset != -1);
+
+		/* If there are duplicate successors, the predecessors may have been removed in
+		 * a previous iteration already. */
+		if (pred_offset == -1) {
+			continue;
+		}
 
 		/* For phis in successor blocks, remove the operands associated with this block */
 		for (phi = next_ssa_block->phis; phi; phi = phi->next) {
diff --git a/ext/opcache/tests/block_removal_with_duplicate_successors.phpt b/ext/opcache/tests/block_removal_with_duplicate_successors.phpt
new file mode 100644
index 0000000000..750a169014
--- /dev/null
+++ b/ext/opcache/tests/block_removal_with_duplicate_successors.phpt
@@ -0,0 +1,15 @@
+--TEST--
+Removing a block that has duplicate successors
+--FILE--
+<?php
+function test($foo) {
+    $bar = 0;
+    if ($bar === 1 && $foo && PHP_SAPI !== 'cli') {
+        echo "foo\n";
+    }
+    echo "bar\n";
+}
+test(1);
+?>
+--EXPECT--
+bar