Fixed bug #78776

By using the normal inheritance check if the parent is abstract
as well.

Author: nikic

NEWS

@@ -8,6 +8,8 @@ PHP                                                                        NEWS
     (Alexey Kachalin)
   . Fixed bug #78973 (Destructor during CV freeing causes segfault if opline
     never saved). (Nikita)
+  . Fixed bug #78776 (Abstract method implementation from trait does not check
+    "static"). (Nikita)
 
 - OPcache:
   . Fixed bug #78961 (erroneous optimization of re-assigned $GLOBALS). (Dmitry)

Zend/tests/bug78776.phpt

@@ -0,0 +1,28 @@
+--TEST--
+Bug #78776: Abstract method implementation from trait does not check "static"
+--FILE--
+<?php
+
+abstract class A
+{
+    abstract public function createApp();
+}
+
+class B extends A
+{
+    use C;
+}
+
+trait C
+{
+    public static function createApp()
+    {
+        echo "You should not be here\n";
+    }
+}
+
+B::createApp();
+
+?>
+--EXPECTF--
+Fatal error: Cannot make non static method A::createApp() static in class C in %s on line %d

Zend/zend_inheritance.c

@@ -812,15 +812,15 @@ static zend_always_inline inheritance_status do_inheritance_check_on_method_ex(z
 		parent = proto;
 	}
 
-	if (!check_only && child_zv && child->common.prototype != proto) {
+	if (!check_only && child->common.prototype != proto) {
 		do {
 			if (child->common.scope != ce
 			 && child->type == ZEND_USER_FUNCTION
 			 && !child->op_array.static_variables) {
 				if (ce->ce_flags & ZEND_ACC_INTERFACE) {
 					/* Few parent interfaces contain the same method */
 					break;
-				} else {
+				} else if (child_zv) {
 					/* op_array wasn't duplicated yet */
 					zend_function *new_function = zend_arena_alloc(&CG(arena), sizeof(zend_op_array));
 					memcpy(new_function, child, sizeof(zend_op_array));
@@ -1585,17 +1585,14 @@ static void zend_add_trait_method(zend_class_entry *ce, const char *name, zend_s
 			}
 			zend_hash_update_mem(*overridden, key, fn, sizeof(zend_function));
 			return;
-		} else if (existing_fn->common.fn_flags & ZEND_ACC_ABSTRACT &&
-				(existing_fn->common.scope->ce_flags & ZEND_ACC_INTERFACE) == 0) {
-			/* Make sure the trait method is compatible with previosly declared abstract method */
-			perform_delayable_implementation_check(
-				ce, fn, existing_fn, /*always_error*/ 1);
-		} else if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
+		} else if ((fn->common.fn_flags & ZEND_ACC_ABSTRACT)
+				&& !(existing_fn->common.fn_flags & ZEND_ACC_ABSTRACT)) {
 			/* Make sure the abstract declaration is compatible with previous declaration */
 			perform_delayable_implementation_check(
 				ce, existing_fn, fn, /*always_error*/ 1);
 			return;
-		} else if (UNEXPECTED(existing_fn->common.scope->ce_flags & ZEND_ACC_TRAIT)) {
+		} else if (UNEXPECTED((existing_fn->common.scope->ce_flags & ZEND_ACC_TRAIT)
+				&& !(existing_fn->common.fn_flags & ZEND_ACC_ABSTRACT))) {
 			/* two traits can't define the same non-abstract method */
 #if 1
 			zend_error_noreturn(E_COMPILE_ERROR, "Trait method %s has not been applied, because there are collisions with other trait methods on %s",