Attempt to fix copy selection as find text bug, issue #497.

src/Edit.c

@@ -4978,7 +4978,7 @@ static INT_PTR CALLBACK EditFindReplaceDlgProc(HWND hwnd, UINT umsg, WPARAM wPar
 	}
 	return TRUE;
 
-	case WM_COPYDATA: {
+	case APPM_COPYDATA: {
 		HWND hwndFind = GetDlgItem(hwnd, IDC_FINDTEXT);
 		HWND hwndRepl = GetDlgItem(hwnd, IDC_REPLACETEXT);
 		LPEDITFINDREPLACE lpefr = (LPEDITFINDREPLACE)GetWindowLongPtr(hwnd, DWLP_USER);

src/Notepad2.c

@@ -3929,8 +3929,8 @@ LRESULT MsgCommand(HWND hwnd, WPARAM wParam, LPARAM lParam) {
 				DestroyWindow(hDlgFindReplace);
 				hDlgFindReplace = EditFindReplaceDlg(hwndEdit, &efrData, bReplace);
 			} else {
-				SendMessage(hDlgFindReplace, WM_COPYDATA, 0, 0);
 				SetForegroundWindow(hDlgFindReplace);
+				SendMessage(hDlgFindReplace, APPM_COPYDATA, 0, 0);
 			}
 		}
 	}

src/Notepad2.h

@@ -103,6 +103,9 @@ typedef struct NP2PARAMS {
 //#define APPM_CHANGENOTIFYCLEAR	(WM_APP + 3)
 #define APPM_TRAYMESSAGE			(WM_APP + 4)	// callback message from system tray
 #define APPM_POST_HOTSPOTCLICK		(WM_APP + 5)
+// TODO: WM_COPYDATA is blocked by the User Interface Privilege Isolation
+// https://www.codeproject.com/tips/1017834/how-to-send-data-from-one-process-to-another-in-cs
+#define APPM_COPYDATA				(WM_APP + 6)
 
 #define ID_WATCHTIMER				0xA000	// file watch timer
 #define ID_PASTEBOARDTIMER			0xA001	// paste board timer