GH-15992: fix error message for single abstract method not implemented

Zend/tests/bug69084.phpt

@@ -26,4 +26,4 @@ $b->main();
 
 ?>
 --EXPECTF--
-Fatal error: Class Bar contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Bar::doOtherStuff) in %s on line %d
+Fatal error: Class Bar contains 1 abstract method and must therefore be declared abstract or implement the remaining method (Bar::doOtherStuff) in %s on line %d

Zend/tests/errmsg_018.phpt

@@ -10,4 +10,4 @@ class test {
 echo "Done\n";
 ?>
 --EXPECTF--
-Fatal error: Class test contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (test::foo) in %s on line %d
+Fatal error: Class test contains 1 abstract method and must therefore be declared abstract or implement the remaining method (test::foo) in %s on line %d

Zend/tests/property_hooks/abstract_get_set_readonly.phpt

@@ -10,4 +10,4 @@ class C extends P {
 }
 ?>
 --EXPECTF--
-Fatal error: Class C contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (P::$prop::set) in %s on line %d
+Fatal error: Class C contains 1 abstract method and must therefore be declared abstract or implement the remaining method (P::$prop::set) in %s on line %d

Zend/tests/property_hooks/abstract_hook_in_non_abstract_class.phpt

@@ -12,4 +12,4 @@ class Test {
 
 ?>
 --EXPECTF--
-Fatal error: Class Test contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Test::$prop::get) in %s on line %d
+Fatal error: Class Test contains 1 abstract method and must therefore be declared abstract or implement the remaining method (Test::$prop::get) in %s on line %d

Zend/tests/property_hooks/abstract_hook_not_implemented.phpt

@@ -14,4 +14,4 @@ class B extends A {}
 
 ?>
 --EXPECTF--
-Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (A::$prop::get) in %s on line %d
+Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining method (A::$prop::get) in %s on line %d

Zend/tests/property_hooks/invalid_abstract_indirect.phpt

@@ -13,4 +13,4 @@ class B extends A {
 
 ?>
 --EXPECTF--
-Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (A::$prop::get) in %s on line %d
+Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining method (A::$prop::get) in %s on line %d

Zend/tests/property_hooks/invalid_abstract_indirect_2.phpt

@@ -12,4 +12,4 @@ class B extends A {
 
 ?>
 --EXPECTF--
-Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (A::$prop::get) in %s on line %d
+Fatal error: Class B contains 1 abstract method and must therefore be declared abstract or implement the remaining method (A::$prop::get) in %s on line %d

Zend/tests/traits/bugs/abstract-methods01.phpt

@@ -16,4 +16,4 @@ $test = new TraitsTest();
 $test->hello();
 ?>
 --EXPECTF--
-Fatal error: Class %s contains %d abstract method and must therefore be declared abstract or implement the remaining methods (%s) in %s on line %d
+Fatal error: Class %s contains %d abstract method and must therefore be declared abstract or implement the remaining method (%s) in %s on line %d

Zend/tests/traits/interface_002.phpt

@@ -21,4 +21,4 @@ new bar;
 
 ?>
 --EXPECTF--
-Fatal error: Class bar contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (baz::abc) in %s on line %d
+Fatal error: Class bar contains 1 abstract method and must therefore be declared abstract or implement the remaining method (baz::abc) in %s on line %d

Zend/zend_inheritance.c

@@ -3009,16 +3009,28 @@ void zend_verify_abstract_class(zend_class_entry *ce) /* {{{ */
 	}
 
 	if (ai.cnt) {
-		zend_error_noreturn(E_ERROR, !is_explicit_abstract && can_be_abstract
-			? "%s %s contains %d abstract method%s and must therefore be declared abstract or implement the remaining methods (" MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT ")"
-			: "%s %s must implement %d abstract private method%s (" MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT ")",
-			zend_get_object_type_uc(ce),
-			ZSTR_VAL(ce->name), ai.cnt,
-			ai.cnt > 1 ? "s" : "",
-			DISPLAY_ABSTRACT_FN(0),
-			DISPLAY_ABSTRACT_FN(1),
-			DISPLAY_ABSTRACT_FN(2)
+		if (!is_explicit_abstract && can_be_abstract) {
+			zend_error_noreturn(E_ERROR,
+				"%s %s contains %d abstract method%s and must therefore be declared abstract or implement the remaining method%s (" MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT ")",
+				zend_get_object_type_uc(ce),
+				ZSTR_VAL(ce->name), ai.cnt,
+				ai.cnt > 1 ? "s" : "",
+				ai.cnt > 1 ? "s" : "",
+				DISPLAY_ABSTRACT_FN(0),
+				DISPLAY_ABSTRACT_FN(1),
+				DISPLAY_ABSTRACT_FN(2)
+			);
+		} else {
+			zend_error_noreturn(E_ERROR,
+				"%s %s must implement %d abstract private method%s (" MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT MAX_ABSTRACT_INFO_FMT ")",
+				zend_get_object_type_uc(ce),
+				ZSTR_VAL(ce->name), ai.cnt,
+				ai.cnt > 1 ? "s" : "",
+				DISPLAY_ABSTRACT_FN(0),
+				DISPLAY_ABSTRACT_FN(1),
+				DISPLAY_ABSTRACT_FN(2)
 			);
+		}
 	} else {
 		/* now everything should be fine and an added ZEND_ACC_IMPLICIT_ABSTRACT_CLASS should be removed */
 		ce->ce_flags &= ~ZEND_ACC_IMPLICIT_ABSTRACT_CLASS;

tests/classes/abstract_by_interface_001.phpt

@@ -30,4 +30,4 @@ class Fails extends Root implements MyInterface {
 object(Leaf)#%d (0) {
 }
 
-Fatal error: Class Fails contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (MyInterface::MyInterfaceFunc) in %sabstract_by_interface_001.php on line %d
+Fatal error: Class Fails contains 1 abstract method and must therefore be declared abstract or implement the remaining method (MyInterface::MyInterfaceFunc) in %sabstract_by_interface_001.php on line %d

tests/classes/abstract_by_interface_002.phpt

@@ -30,4 +30,4 @@ class Fails extends Root implements MyInterface {
 object(Leaf)#%d (0) {
 }
 
-Fatal error: Class Fails contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (MyInterface::MyInterfaceFunc) in %sabstract_by_interface_002.php on line %d
+Fatal error: Class Fails contains 1 abstract method and must therefore be declared abstract or implement the remaining method (MyInterface::MyInterfaceFunc) in %sabstract_by_interface_002.php on line %d

tests/classes/abstract_derived.phpt

@@ -13,4 +13,4 @@ class derived extends base {
 ?>
 ===DONE===
 --EXPECTF--
-Fatal error: Class derived contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (derived::show) in %sabstract_derived.php on line %d
+Fatal error: Class derived contains 1 abstract method and must therefore be declared abstract or implement the remaining method (derived::show) in %sabstract_derived.php on line %d

tests/classes/abstract_not_declared.phpt

@@ -10,4 +10,4 @@ class fail {
 echo "Done\n"; // shouldn't be displayed
 ?>
 --EXPECTF--
-Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (fail::show) in %s on line %d
+Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining method (fail::show) in %s on line %d

tests/classes/abstract_redeclare.phpt

@@ -16,4 +16,4 @@ class fail extends pass {
 echo "Done\n"; // Shouldn't be displayed
 ?>
 --EXPECTF--
-Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (fail::show) in %sabstract_redeclare.php on line %d
+Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining method (fail::show) in %sabstract_redeclare.php on line %d

tests/classes/abstract_static.phpt

@@ -31,4 +31,4 @@ echo "Done\n"; // shouldn't be displayed
 --EXPECTF--
 Call to function show()
 
-Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (fail::func) in %sabstract_static.php(%d) : eval()'d code on line %d
+Fatal error: Class fail contains 1 abstract method and must therefore be declared abstract or implement the remaining method (fail::func) in %sabstract_static.php(%d) : eval()'d code on line %d

tests/classes/interface_must_be_implemented.phpt

@@ -12,4 +12,4 @@ class derived_a implements if_a {
 
 ?>
 --EXPECTF--
-Fatal error: Class derived_a contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (if_a::f_a) in %s on line %d
+Fatal error: Class derived_a contains 1 abstract method and must therefore be declared abstract or implement the remaining method (if_a::f_a) in %s on line %d

tests/classes/interfaces_002.phpt

@@ -23,4 +23,4 @@ echo "Message: " . $foo->getMessage() . "\n";
 ?>
 ===DONE===
 --EXPECTF--
-Fatal error: Class Exception_foo contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (ThrowableInterface::getErrno) in %s on line %d
+Fatal error: Class Exception_foo contains 1 abstract method and must therefore be declared abstract or implement the remaining method (ThrowableInterface::getErrno) in %s on line %d