give error when mapping fails

Cheat Engine/FileMapping.pas

@@ -67,19 +67,24 @@ constructor TFileMapping.create(filename: string);
   try
     //open file
     FileHandle := CreateFile(PChar(filename), GENERIC_READ or GENERIC_WRITE, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
-    if FileHandle = INVALID_HANDLE_VALUE then
+    if (FileHandle = 0) or (FileHandle=INVALID_HANDLE_VALUE) then
       FileHandle := CreateFile(PChar(filename), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
 
-    if FileHandle = INVALID_HANDLE_VALUE then
+    if (FileHandle = 0) or (FileHandle=INVALID_HANDLE_VALUE) then
       raise EFileMapError.create(Format(rsDoesNotExist, [filename]));
 
 
     FFileSize:=0;
     FFileSize:=GetFileSize(FileHandle,pointer(ptruint(@fileSize)+4));
 
+    if FFileSize=0 then
+      raise EFileMapError.create('Can not map an empty file');
+
+
     //still here, so create filemapping
     FileMapping := CreateFileMapping(FileHandle, nil, PAGE_WRITECOPY	, 0, 0, nil);
-    if FileMapping = 0 then raise EFileMapError.create(rsMappingFailed);
+    if (FileMapping = 0) or (FileMapping=INVALID_HANDLE_VALUE) then
+      raise EFileMapError.create(rsMappingFailed);
 
     //map it completely
     FFileContent:= MapViewOfFile(FileMapping, FILE_MAP_COPY , 0, 0, 0);