Revised 'Fixed a possible deadlock when detaching a receiver from a device' from version 2.3.9, which sometimes caused a black screen when switching channels

CONTRIBUTORS

@@ -3607,3 +3607,6 @@ J
  for reporting a possible discrepancy of the primary device number in the LSTD and
  PRIM commands
  for adding support for EAC3 audio from other sources
+
+Stefan Verse <Verse@amotronics.de>
+ for fixing an occasional black screen when switching channels

HISTORY

@@ -9463,3 +9463,6 @@ Video Disk Recorder Revision History
 - Added a device hook for detecting whether a device provides EIT data (thanks to
   Winfried K<>hler).
 - Fixed memory handling in cString::Append() (reported by Stefan Herdler).
+- Revised 'Fixed a possible deadlock when detaching a receiver from a device' from
+  version 2.3.9, which sometimes caused a black screen when switching channels
+  (thanks to Stefan Verse).

device.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: device.c 4.31 2020/06/10 14:52:43 kls Exp $
+ * $Id: device.c 4.32 2020/06/12 09:28:44 kls Exp $
  */
 
 #include "device.h"
@@ -1822,17 +1822,16 @@ void cDevice::Detach(cReceiver *Receiver)
   bool receiversLeft = false;
   mutexReceiver.Lock();
   for (int i = 0; i < MAXRECEIVERS; i++) {
-      if (receiver[i] == Receiver) {
+      if (receiver[i] == Receiver)
          receiver[i] = NULL;
-         Receiver->device = NULL;
-         Receiver->Activate(false);
-         for (int n = 0; n < Receiver->numPids; n++)
-             DelPid(Receiver->pids[n]);
-         }
       else if (receiver[i])
          receiversLeft = true;
       }
   mutexReceiver.Unlock();
+  Receiver->device = NULL;
+  Receiver->Activate(false);
+  for (int n = 0; n < Receiver->numPids; n++)
+      DelPid(Receiver->pids[n]);
   if (camSlot) {
      if (Receiver->priority > MINPRIORITY) { // priority check to avoid an infinite loop with the CAM slot's caPidReceiver
         camSlot->StartDecrypting();