Use optimized zend_array_dup_immutable()

We can make some assumptions about the value of the fields.

Author: iluuu1994

Zend/zend_hash.c

@@ -2435,6 +2435,34 @@ static zend_always_inline uint32_t zend_array_dup_elements(const HashTable *sour
 	return idx;
 }
 
+ZEND_API HashTable* ZEND_FASTCALL zend_array_dup_immutable(const HashTable *source)
+{
+	IS_CONSISTENT(source);
+	ZEND_ASSERT(GC_FLAGS(source) & IS_ARRAY_IMMUTABLE);
+
+	HashTable *target;
+	ALLOC_HASHTABLE(target);
+
+	*target = *source;
+
+	/* Immutable arrays don't have an iterator count. */
+	ZEND_ASSERT(HT_FLAGS(source) == (HT_FLAGS(source) & HASH_FLAG_MASK));
+
+	GC_SET_REFCOUNT(target, 1);
+	GC_TYPE_INFO(target) = GC_ARRAY;
+	target->pDestructor = ZVAL_PTR_DTOR;
+
+	if (HT_IS_PACKED(source)) {
+		HT_SET_DATA_ADDR(target, emalloc(HT_PACKED_SIZE(target)));
+		memcpy(HT_GET_DATA_ADDR(target), HT_GET_DATA_ADDR(source), HT_PACKED_USED_SIZE(source));
+	} else {
+		HT_SET_DATA_ADDR(target, emalloc(HT_SIZE(target)));
+		memcpy(HT_GET_DATA_ADDR(target), HT_GET_DATA_ADDR(source), HT_USED_SIZE(source));
+	}
+
+	return target;
+}
+
 ZEND_API HashTable* ZEND_FASTCALL zend_array_dup(const HashTable *source)
 {
 	uint32_t idx;

Zend/zend_hash.h

@@ -345,6 +345,7 @@ ZEND_API HashTable* ZEND_FASTCALL _zend_new_array(uint32_t size);
 ZEND_API HashTable* ZEND_FASTCALL zend_new_pair(const zval *val1, const zval *val2);
 ZEND_API uint32_t zend_array_count(HashTable *ht);
 ZEND_API HashTable* ZEND_FASTCALL zend_array_dup(const HashTable *source);
+ZEND_API HashTable* ZEND_FASTCALL zend_array_dup_immutable(const HashTable *source);
 ZEND_API void ZEND_FASTCALL zend_array_destroy(HashTable *ht);
 ZEND_API HashTable* zend_array_to_list(const HashTable *source);
 ZEND_API void ZEND_FASTCALL zend_symtable_clean(HashTable *ht);

Zend/zend_vm_def.h

@@ -6442,7 +6442,7 @@ ZEND_VM_HANDLER(210, ZEND_ARRAY_DUP, CONST, UNUSED)
 	zend_array *copy;
 	USE_OPLINE
 
-	copy = zend_array_dup(Z_ARRVAL_P(GET_OP1_ZVAL_PTR(BP_VAR_R)));
+	copy = zend_array_dup_immutable(Z_ARRVAL_P(GET_OP1_ZVAL_PTR(BP_VAR_R)));
 	ZVAL_ARR(EX_VAR(opline->result.var), copy);
 
 	ZEND_VM_NEXT_OPCODE();