Fix skipped lazy init on primed SIMPLE_WRITE

Go through the normal assignment path, which includes an IS_UNDEF check.

Fixes GH-17998
Closes GH-17999

NEWS

@@ -15,6 +15,8 @@ PHP                                                                        NEWS
     (nielsdos)
   . Fixed bug GH-17988 (Incorrect handling of hooked props without get hook in
     get_object_vars()). (ilutov)
+  . Fixed bug GH-17998 (Skipped lazy object initialization on primed
+    SIMPLE_WRITE cache). (ilutov)
 
 - DOM:
   . Fixed bug GH-17991 (Assertion failure dom_attr_value_write). (nielsdos)

Zend/tests/lazy_objects/gh17998.phpt

@@ -0,0 +1,31 @@
+--TEST--
+GH-17998: Skipped lazy init on primed SIMPLE_WRITE
+--FILE--
+<?php
+
+class C {
+    public $prop {
+        set => $value;
+    }
+}
+
+$nonLazy = new C;
+
+$lazy = (new ReflectionClass(C::class))->newLazyProxy(function () {
+    echo "init\n";
+    return new C;
+});
+
+function foo(C $c) {
+    $c->prop = 1;
+    var_dump($c->prop);
+}
+
+foo($nonLazy);
+foo($lazy);
+
+?>
+--EXPECT--
+int(1)
+init
+int(1)

Zend/zend_vm_def.h

@@ -2450,12 +2450,14 @@ ZEND_VM_C_LABEL(assign_object):
 			void **cache_slot = CACHE_ADDR(opline->extended_value);
 			uintptr_t prop_offset = (uintptr_t)CACHED_PTR_EX(cache_slot + 1);
 			zval *property_val;
+			zend_property_info *prop_info;
 
 			if (EXPECTED(IS_VALID_PROPERTY_OFFSET(prop_offset))) {
+				prop_info = (zend_property_info*) CACHED_PTR_EX(cache_slot + 2);
+
+ZEND_VM_C_LABEL(assign_obj_simple):
 				property_val = OBJ_PROP(zobj, prop_offset);
 				if (Z_TYPE_P(property_val) != IS_UNDEF) {
-					zend_property_info *prop_info = (zend_property_info*) CACHED_PTR_EX(cache_slot + 2);
-
 					if (prop_info != NULL) {
 						value = zend_assign_to_typed_prop(prop_info, property_val, value, &garbage EXECUTE_DATA_CC);
 						ZEND_VM_C_GOTO(free_and_exit_assign_obj);
@@ -2527,14 +2529,12 @@ ZEND_VM_C_LABEL(fast_assign_obj):
 			} else {
 				ZEND_ASSERT(IS_HOOKED_PROPERTY_OFFSET(prop_offset));
 				if (ZEND_IS_PROPERTY_HOOK_SIMPLE_WRITE(prop_offset)) {
-					zend_property_info *prop_info = CACHED_PTR_EX(cache_slot + 2);
-					property_val = OBJ_PROP(zobj, prop_info->offset);
-					if (ZEND_TYPE_IS_SET(prop_info->type)) {
-						value = zend_assign_to_typed_prop(prop_info, property_val, value, &garbage EXECUTE_DATA_CC);
-						ZEND_VM_C_GOTO(free_and_exit_assign_obj);
-					} else {
-						ZEND_VM_C_GOTO(fast_assign_obj);
+					prop_info = CACHED_PTR_EX(cache_slot + 2);
+					prop_offset = prop_info->offset;
+					if (!ZEND_TYPE_IS_SET(prop_info->type)) {
+						prop_info = NULL;
 					}
+					ZEND_VM_C_GOTO(assign_obj_simple);
 				}
 				/* Fall through to write_property for hooks. */
 			}