Fixed Bug #55355: Inheritance chain was not regarded when checking whether the abstract method of a trait is satisfied.

Zend/tests/traits/bug55355.phpt

@@ -0,0 +1,46 @@
+--TEST--
+Bug #55355 (Abstract functions required by a trait are not correctly found when implemented in an ancestor class)
+--FILE--
+<?php
+
+// A trait that has a abstract function
+trait ATrait {
+	function bar() {
+		$this->foo();
+	}
+	abstract function foo(); 
+}
+
+// A class on the second level in the
+// inheritance chain
+class Level2Impl {
+	function foo() {}
+}
+
+class Level1Indirect extends Level2Impl {}
+
+// A class on the first level in the
+// inheritance chain
+class Level1Direct {
+    function foo() {}
+}
+
+// Trait Uses
+
+class Direct {
+    use ATrait;
+    function foo() {}
+}
+
+class BaseL2 extends Level1Indirect {
+    use ATrait;
+}
+
+class BaseL1 extends Level1Direct {
+    use ATrait;
+}
+
+echo 'DONE';
+?>
+--EXPECT--
+DONE

Zend/zend_compile.c

@@ -3645,6 +3645,14 @@ static int zend_traits_merge_functions_to_class(zend_function *fn TSRMLS_DC, int
 		zend_function* parent_function;
 		if (ce->parent && zend_hash_quick_find(&ce->parent->function_table, hash_key->arKey, hash_key->nKeyLength, hash_key->h, (void**) &parent_function) != FAILURE) {
 			prototype = parent_function; /* ->common.fn_flags |= ZEND_ACC_ABSTRACT; */
+			
+			/* we got that method in the parent class, and are going to override it,
+			   except, if the trait is just asking to have an abstract method implemented. */
+			if (fn->common.fn_flags & ZEND_ACC_ABSTRACT) {
+				/* then we clean up an skip this method */
+				zend_function_dtor(fn);
+				return ZEND_HASH_APPLY_REMOVE;
+			}
 		}
 
 		fn->common.scope = ce;