Fix #77627 method_exists on Closure::__invoke

Author: krakjoe

NEWS

@@ -8,6 +8,8 @@ PHP                                                                        NEWS
 - Standard:
   . Fixed bug #81048 (phpinfo(INFO_VARIABLES) "Array to string conversion").
     (cmb)
+  . Fixed bug #77627 (method_exists on Closure::__invoke inconsistency).
+    (krakjoe)
 
 03 Jun 2021, PHP 8.0.7
 

Zend/tests/bug77627.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Fix for #77627 method_exists on Closure::__invoke without object returns false
+--FILE--
+<?php
+var_dump(method_exists(Closure::class, "__invoke"));
+var_dump(method_exists(Closure::class, "__INVOKE"));
+
+$closure = function(){};
+
+var_dump(method_exists($closure, "__INVOKE"));
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)

Zend/zend_builtin_functions.c

@@ -950,16 +950,22 @@ ZEND_FUNCTION(method_exists)
 		func = Z_OBJ_HT_P(klass)->get_method(&obj, method_name, NULL);
 		if (func != NULL) {
 			if (func->common.fn_flags & ZEND_ACC_CALL_VIA_TRAMPOLINE) {
-				/* Returns true to the fake Closure's __invoke */
+				/* Returns true for the fake Closure's __invoke */
 				RETVAL_BOOL(func->common.scope == zend_ce_closure
-					&& zend_string_equals_literal(method_name, ZEND_INVOKE_FUNC_NAME));
+					&& zend_string_equals_literal_ci(method_name, ZEND_INVOKE_FUNC_NAME));
 
 				zend_string_release_ex(func->common.function_name, 0);
 				zend_free_trampoline(func);
 				return;
 			}
 			RETURN_TRUE;
 		}
+	} else {
+	    /* Returns true for fake Closure::__invoke */
+	    if (ce == zend_ce_closure
+	        && zend_string_equals_literal_ci(method_name, ZEND_INVOKE_FUNC_NAME)) {
+	        RETURN_TRUE;
+	    }
 	}
 	RETURN_FALSE;
 }