win/tclWinChan.c Tcl_InitNotifier: Bug [2413550] Avoid reopening of serial channels which causes issues with Bluetooth virtual com. Patch by Rolf Schroedter.

1 files changed, 15 insertions, 10 deletions

diff --git a/win/tclWinSerial.c b/win/tclWinSerial.c
index d5244ac..312a2f8 100644
--- a/win/tclWinSerial.c
+++ b/win/tclWinSerial.c
@@ -1410,23 +1410,22 @@ SerialWriterThread(
 /*
  *----------------------------------------------------------------------
  *
- * TclWinSerialReopen --
+ * TclWinSerialOpen --
  *
- *	Reopens the serial port with the OVERLAPPED FLAG set
+ *	Opens or Reopens the serial port with the OVERLAPPED FLAG set
  *
  * Results:
- *	Returns the new handle, or INVALID_HANDLE_VALUE. Normally there
- *	shouldn't be any error, because the same channel has previously been
- *	succeesfully opened.
+ *	Returns the new handle, or INVALID_HANDLE_VALUE. 
+ *	I an existing channel is specified it is closed and reopened.
  *
  * Side effects:
- *	May close the original handle
+ *	May close/reopen the original handle
  *
  *----------------------------------------------------------------------
  */
 
 HANDLE
-TclWinSerialReopen(
+TclWinSerialOpen(
     HANDLE handle,
     CONST TCHAR *name,
     DWORD access)
@@ -1434,16 +1433,22 @@ TclWinSerialReopen(
     SerialInit();
 
     /*
+     * If an open channel is specified, close it
+     */
+
+    if ( handle != INVALID_HANDLE_VALUE && CloseHandle(handle) == FALSE) {
+	return INVALID_HANDLE_VALUE;
+    }
+
+    /*
      * Multithreaded I/O needs the overlapped flag set otherwise
      * ClearCommError blocks under Windows NT/2000 until serial output is
      * finished
      */
 
-    if (CloseHandle(handle) == FALSE) {
-	return INVALID_HANDLE_VALUE;
-    }
     handle = (*tclWinProcs->createFileProc)(name, access, 0, 0,
 	    OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
+
     return handle;
 }