Add separate static property through trait if parent already declares it

Fixes GH-10935
Closes GH-10937

NEWS

@@ -29,6 +29,8 @@ PHP                                                                        NEWS
     (ilutov)
   . Fix bug GH-10168, GH-10582 (Various segfaults with destructors and VM return
     values). (dstogov, nielsdos, ilutov)
+  . Fix bug GH-10935 (Use of trait doesn't redeclare static property if class
+    has inherited it from its parent). (ilutov)
 
 - Date:
   . Implement More Appropriate Date/Time Exceptions RFC. (Derick)

UPGRADING

@@ -35,6 +35,10 @@ PHP 8.3 UPGRADE NOTES
     proc_get_status() to check whether the result was cached.
   . Zend Max Execution Timers is now enabled by default for ZTS builds on
     Linux.
+  . Uses of traits with static properties will now redeclare static properties
+    inherited from the parent class. This will create a separate static property
+    storage for the current class. This is analogous to adding the static
+    property to the class directly without traits.
 
 - FFI:
   . C functions that have a return type of void now return null instead of

Zend/tests/gh10935.phpt

@@ -0,0 +1,83 @@
+--TEST--
+GH-1093: Add separate static property through trait if parent already declares it
+--FILE--
+<?php
+trait Foo {
+    static $test;
+
+    public static function getFooSelf() {
+        return self::$test;
+    }
+
+    public static function getFooStatic() {
+        return static::$test;
+    }
+}
+trait Bar {
+    public static function getBarSelf() {
+        return self::$test;
+    }
+
+    public static function getBarStatic() {
+        return static::$test;
+    }
+}
+
+class A {
+    use Foo;
+    use Bar;
+
+    public static function getASelf() {
+        return self::$test;
+    }
+
+    public static function getAStatic() {
+        return static::$test;
+    }
+}
+
+class B extends A {
+    use Foo;
+
+    public static function getBSelf() {
+        return self::$test;
+    }
+
+    public static function getBStatic() {
+        return static::$test;
+    }
+}
+
+A::$test = 'A';
+B::$test = 'B';
+
+echo 'A::$test: ' . A::$test . "\n";
+echo 'A::getASelf(): ' . A::getASelf() . "\n";
+echo 'A::getAStatic(): ' . A::getAStatic() . "\n";
+echo 'A::getFooSelf(): ' . A::getFooSelf() . "\n";
+echo 'A::getFooStatic(): ' . A::getFooStatic() . "\n";
+echo 'B::$test: ' . B::$test . "\n";
+echo 'B::getASelf(): ' . B::getASelf() . "\n";
+echo 'B::getAStatic(): ' . B::getAStatic() . "\n";
+echo 'B::getBSelf(): ' . B::getBSelf() . "\n";
+echo 'B::getBStatic(): ' . B::getBStatic() . "\n";
+echo 'B::getFooSelf(): ' . B::getFooSelf() . "\n";
+echo 'B::getFooStatic(): ' . B::getFooStatic() . "\n";
+echo 'B::getBarSelf(): ' . B::getBarSelf() . "\n";
+echo 'B::getBarStatic(): ' . B::getBarStatic() . "\n";
+?>
+--EXPECT--
+A::$test: A
+A::getASelf(): A
+A::getAStatic(): A
+A::getFooSelf(): A
+A::getFooStatic(): A
+B::$test: B
+B::getASelf(): A
+B::getAStatic(): B
+B::getBSelf(): B
+B::getBStatic(): B
+B::getFooSelf(): B
+B::getFooStatic(): B
+B::getBarSelf(): A
+B::getBarStatic(): B

Zend/zend_inheritance.c

@@ -2377,7 +2377,9 @@ static void zend_do_traits_property_binding(zend_class_entry *ce, zend_class_ent
 								ZSTR_VAL(prop_name),
 								ZSTR_VAL(ce->name));
 					}
-					continue;
+					if (!(flags & ZEND_ACC_STATIC)) {
+						continue;
+					}
 				}
 			}
 

ext/opcache/zend_persist.c

@@ -1082,7 +1082,15 @@ void zend_update_parent_ce(zend_class_entry *ce)
 				end = parent->parent ? parent->parent->default_static_members_count : 0;
 				for (; i >= end; i--) {
 					zval *p = &ce->default_static_members_table[i];
-					ZVAL_INDIRECT(p, &parent->default_static_members_table[i]);
+					/* The static property may have been overridden by a trait
+					 * during inheritance. In that case, the property default
+					 * value is replaced by zend_declare_typed_property() at the
+					 * property index of the parent property. Make sure we only
+					 * point to the parent property value if the child value was
+					 * already indirect. */
+					if (Z_TYPE_P(p) == IS_INDIRECT) {
+						ZVAL_INDIRECT(p, &parent->default_static_members_table[i]);
+					}
 				}
 
 				parent = parent->parent;