2 files changed, 20 insertions, 2 deletions
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index 684a9c50..eecae136 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -640,7 +640,7 @@ bool native_slot_set(upb_fieldtype_t type, const zend_class_entry* klass,
 bool native_slot_set_by_array(upb_fieldtype_t type,
                               const zend_class_entry* klass, void* memory,
                               zval* value TSRMLS_DC);
-void native_slot_init(upb_fieldtype_t type, void* memory, void* cache);
+void native_slot_init(upb_fieldtype_t type, void* memory, CACHED_VALUE* cache);
 // For each property, in order to avoid conversion between the zval object and
 // the actual data type during parsing/serialization, the containing message
 // object use the custom memory layout to store the actual data type for each
diff --git a/php/ext/google/protobuf/storage.c b/php/ext/google/protobuf/storage.c
index 29a3db86..c0e4da3e 100644
--- a/php/ext/google/protobuf/storage.c
+++ b/php/ext/google/protobuf/storage.c
@@ -210,7 +210,7 @@ bool native_slot_set_by_array(upb_fieldtype_t type,
   return true;
 }
 
-void native_slot_init(upb_fieldtype_t type, void* memory, void* cache) {
+void native_slot_init(upb_fieldtype_t type, void* memory, CACHED_VALUE* cache) {
   zval* tmp = NULL;
   switch (type) {
     case UPB_TYPE_FLOAT:
@@ -224,6 +224,9 @@ void native_slot_init(upb_fieldtype_t type, void* memory, void* cache) {
       break;
     case UPB_TYPE_STRING:
     case UPB_TYPE_BYTES:
+      DEREF(memory, CACHED_VALUE*) = cache;
+      ZVAL_EMPTY_STRING(CACHED_PTR_TO_ZVAL_PTR(cache));
+      break;
     case UPB_TYPE_MESSAGE:
       DEREF(memory, CACHED_VALUE*) = cache;
       break;
@@ -621,6 +624,21 @@ void layout_init(MessageLayout* layout, void* storage,
     int cache_index = slot_property_cache(layout, storage, field);
     CACHED_VALUE* property_ptr = &properties_table[cache_index];
 
+    // Clean up initial value by generated code. In the generated code of
+    // previous versions, each php field is given an initial value. However, the
+    // order to initialize these fields may not be consistent with the order of
+    // upb fields.
+    if (Z_TYPE_P(CACHED_PTR_TO_ZVAL_PTR(property_ptr)) == IS_STRING) {
+#if PHP_MAJOR_VERSION < 7
+      if (!IS_INTERNED(Z_STRVAL_PP(property_ptr))) {
+        FREE(Z_STRVAL_PP(property_ptr));
+      }
+#else
+      zend_string_release(Z_STR_P(property_ptr));
+#endif
+    }
+    ZVAL_NULL(CACHED_PTR_TO_ZVAL_PTR(property_ptr));
+
     if (upb_fielddef_containingoneof(field)) {
       memset(memory, 0, NATIVE_SLOT_MAX_SIZE);
       *oneof_case = ONEOF_CASE_NONE;