Terminal: Fix possible double lock

Check if fMouseClipboard is be_clipboard, and do nothing in that case.
This could happen if SetMouseClipboard has never been called, for example when running as a replicant.
Also updated copyright year.

Change-Id: I2468d80404c429797bd8c906f3aa747ffc414fa8
Reviewed-on: https://review.haiku-os.org/c/haiku/+/9309
Tested-by: Commit checker robot <[email protected]>
Reviewed-by: Adrien Destugues <[email protected]>

src/apps/terminal/TermView.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2023, Haiku, Inc. All rights reserved.
+ * Copyright 2001-2025, Haiku, Inc. All rights reserved.
  * Copyright 2003-2004 Kian Duffy, [email protected]
  * Parts Copyright 1998-1999 Kazuho Okui and Takashi Murai.
  * All rights reserved. Distributed under the terms of the MIT license.
@@ -1695,7 +1695,7 @@ TermView::MessageReceived(BMessage *message)
 			// This message originates from the system clipboard. Overwrite
 			// the contents of the mouse clipboard with the ones from the
 			// system clipboard, in case it contains text data.
-			if (be_clipboard->Lock()) {
+			if (be_clipboard != fMouseClipboard && be_clipboard->Lock()) {
 				if (fMouseClipboard->Lock()) {
 					BMessage* clipMsgA = be_clipboard->Data();
 					const char* text;