Fix incorrect match default branch optimization

Fixes GH-11134

Author: iluuu1994

Zend/Optimizer/dfa_pass.c

@@ -1001,11 +1001,23 @@ static int zend_dfa_optimize_jmps(zend_op_array *op_array, zend_ssa *ssa)
 							|| (opline->opcode == ZEND_MATCH && (type == IS_LONG || type == IS_STRING));
 
 						if (!correct_type) {
-							removed_ops++;
-							MAKE_NOP(opline);
-							opline->extended_value = 0;
-							take_successor_ex(ssa, block_num, block, block->successors[block->successors_count - 1]);
-							goto optimize_nop;
+							if (opline->opcode != ZEND_MATCH) {
+								removed_ops++;
+								MAKE_NOP(opline);
+								opline->extended_value = 0;
+								take_successor_ex(ssa, block_num, block, block->successors[block->successors_count - 1]);
+								goto optimize_nop;
+							} else {
+								/* Match doesn't have a fallback chain, so we need to jump directly to the default branch. */
+								uint32_t target = ZEND_OFFSET_TO_OPLINE_NUM(op_array, opline, opline->extended_value);
+								opline->opcode = ZEND_JMP;
+								opline->extended_value = 0;
+								SET_UNUSED(opline->op1);
+								ZEND_SET_OP_JMP_ADDR(opline, opline->op1, op_array->opcodes + target);
+								SET_UNUSED(opline->op2);
+								take_successor_ex(ssa, block_num, block, ssa->cfg.map[target]);
+								goto optimize_jmp;
+							}
 						} else {
 							HashTable *jmptable = Z_ARRVAL_P(CT_CONSTANT_EX(op_array, opline->op2.constant));
 							zval *jmp_zv = type == IS_LONG

Zend/tests/match/gh11134.phpt

@@ -0,0 +1,28 @@
+--TEST--
+GH-11134: Incorrect match optimization
+--FILE--
+<?php
+
+function testMatch() {
+    return match ($unset ?? null) {
+        'foo' => 'foo',
+        'bar' => 'bar',
+        default => 'baz',
+    };
+}
+
+function testSwitch() {
+    switch ($unset ?? null) {
+        case 'foo': return 'foo';
+        case 'bar': return 'bar';
+        default: return 'baz';
+    }
+}
+
+var_dump(testMatch());
+var_dump(testSwitch());
+
+?>
+--EXPECT--
+string(3) "baz"
+string(3) "baz"