* fix #40595: correctly access the list of parameters of the extended method table

+ added test

rtl/objpas/typinfo.pp

@@ -4622,7 +4622,7 @@ begin
   if Index >= ParamCount then
     Result := Nil
   else
-    Result := PVmtMethodParamArray(@params)[Index];
+    Result := PVmtMethodParam(@params) + Index;
 end;
 
 function TVMTMethodExEntry.GetResultLocs: PParameterLocations;

tests/webtbs/tw40595.pp

@@ -0,0 +1,74 @@
+Program tw40595;
+
+{$mode OBJFPC}{$H+}{$M+}
+{$Modeswitch advancedrecords}
+{$RTTI EXPLICIT PROPERTIES([vcPrivate,vcProtected,vcPublic,vcPublished])}
+{$RTTI EXPLICIT FIELDS([vcPrivate,vcProtected,vcPublic,vcPublished])}
+{$RTTI EXPLICIT METHODS([vcPrivate,vcProtected,vcPublic,vcPublished])}
+
+Uses
+  SysUtils,
+  TypInfo;
+
+Type
+  { TUser }
+
+  TUser = Class
+  Private
+    FName: string;
+    FID: Integer;
+  Public
+    Procedure PrintID;
+    Constructor Create;
+    Procedure PrintName;
+  Published
+    Property ID: Integer read FID write FID;
+    Property Name: string read FName write FName;
+  End;
+
+  { TUser }
+
+  Constructor TUser.Create;
+  Begin
+    FName := 'TUser.Name: ' + WChar($20A1) + ' ' + WChar($2211);
+  End;
+
+  Procedure TUser.PrintID;
+  Begin
+    WriteLn('User ID   : ', ID);
+  End;
+
+  Procedure TUser.PrintName;
+  Begin
+    WriteLn('User Name : ', Name);
+  End;
+
+const
+  MethodNames: array of String = (
+    'PrintID',
+    'Create',
+    'PrintName'
+  );
+Var
+  I: Integer;
+  Count: LongInt;
+  Method: PVmtMethodExEntry;
+  Methods: PExtendedMethodInfoTable;
+Begin
+  Count := GetMethodList(TUser, Methods, []);
+  If Methods <> nil Then
+  Begin
+    if Count <> Length(MethodNames) then
+      Halt(2);
+    For I := 0 To Pred(Count) Do
+    Begin
+      Method := Methods^[I];
+      if Method^.Name <> MethodNames[i] then
+        Halt(3 + i);
+      WriteLn(Format('%-10s - %d', [Method^.Name, Method^.Kind]));
+    End;
+    Freemem(Methods);
+  End else
+    Halt(1);
+End.
+