Fix block removal if there are duplicate successors

php · Jul 22, 2017 · 96665fb · 96665fb
1 parent 1e9ad4a
commit 96665fb
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Showing 2 changed files with 21 additions and 1 deletion.
diff --git 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
@@ -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