(svn r26544) [1.4] -Backport from trunk:

- Fix: [Windows] Crash when the operating system performs the "paint" callback during window creation [FS#5994] (r26539, r26538)
- Fix: OpenBSD compilation [FS#5992] (r26523)
- Fix: prevent from ever reading huge (or negative) amounts of data in strgen (r26521)
- Fix: Severity rating of dedicated server messages during world generation (r26518)

src/network/network_chat_gui.cpp

@@ -167,7 +167,7 @@ void NetworkUndrawChatMessage()
 		/* Put our 'shot' back to the screen */
 		blitter->CopyFromBuffer(blitter->MoveTo(_screen.dst_ptr, x, y), _chatmessage_backup, width, height);
 		/* And make sure it is updated next time */
-		_video_driver->MakeDirty(x, y, width, height);
+		VideoDriver::GetInstance()->MakeDirty(x, y, width, height);
 
 		_chatmessage_dirty = true;
 	}
@@ -254,7 +254,7 @@ void NetworkDrawChatMessage()
 	}
 
 	/* Make sure the data is updated next flush */
-	_video_driver->MakeDirty(x, y, width, height);
+	VideoDriver::GetInstance()->MakeDirty(x, y, width, height);
 
 	_chatmessage_visible = true;
 	_chatmessage_dirty = false;