fix: do not use the RTSP restream when ZM_MIN_RTSP_PORT is not set

ZoneMinder's RTSP server only starts when ZM_MIN_RTSP_PORT is set, and it
defaults to empty. The go2rtc and Janus managers decided to use the
restream from the monitor's RTSP Server flag (Janus: its restream flag)
alone, so with the port unset they built rtsp://127.0.0.1:0/<name>.
go2rtc was given that as the monitor's primary stream and as
<id>_ZoneMinderPrimary, neither of which can play; Janus pointed its
mountpoint at it.

Use the restream only when the port is set as well, and warn when a
monitor asks for it without one, so the camera's own stream is used.
MonitorStream applies the same test before choosing the
_ZoneMinderPrimary stream, which is no longer registered in that case.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/zm_monitor_go2rtc.cpp

@@ -43,7 +43,13 @@ Monitor::Go2RTCManager::Go2RTCManager(Monitor *parent_)
     Warning("Go2RTC: No endpoint configured in ZM_GO2RTC_PATH, using default: %s", Go2RTC_endpoint.c_str());
   }
 
-  Use_RTSP_Restream = parent->RTSPServer();
+  // ZoneMinder's RTSP server only runs when ZM_MIN_RTSP_PORT is set, so without it
+  // there is no restream to point go2rtc at; use the camera's own stream instead.
+  Use_RTSP_Restream = parent->RTSPServer() && config.min_rtsp_port;
+  if (parent->RTSPServer() && !config.min_rtsp_port) {
+    Warning("Go2RTC: monitor %u has RTSP Server enabled but ZM_MIN_RTSP_PORT is not set, "
+            "so there is no restream; using the camera stream", parent->Id());
+  }
   if (Use_RTSP_Restream) {
     if (parent->server_id) {
       Server server(parent->server_id);

src/zm_monitor_janus.cpp

@@ -39,7 +39,12 @@ Monitor::JanusManager::~JanusManager() {
 
 void Monitor::JanusManager::load_from_monitor() {
   //constructor takes care of init and calls add_to
-  Use_RTSP_Restream = parent->restream;
+  // The restream needs ZoneMinder's RTSP server, which only runs when ZM_MIN_RTSP_PORT is set.
+  Use_RTSP_Restream = parent->restream && config.min_rtsp_port;
+  if (parent->restream && !config.min_rtsp_port) {
+    Warning("Janus: monitor %u is set to use the RTSP restream but ZM_MIN_RTSP_PORT is not set, "
+            "so there is no restream; using the camera stream", parent->Id());
+  }
   profile_override = parent->janus_profile_override;
   rtsp_session_timeout = parent->janus_rtsp_session_timeout;
   if ((config.janus_path != nullptr) && (config.janus_path[0] != '\0')) {

web/js/MonitorStream.js

@@ -35,7 +35,10 @@ function MonitorStream(monitorData) {
   this.RTSP2WebEnabled = monitorData.RTSP2WebEnabled;
   this.RTSP2WebType = null;
   this.StreamChannel = monitorData.StreamChannel;
-  this.RTSPServer = monitorData.RTSPServer;
+  // ZoneMinder's RTSP restream only exists when its RTSP server runs, which needs
+  // ZM_MIN_RTSP_PORT; without it zmc registers no ZoneMinderPrimary stream.
+  this.RTSPServer = monitorData.RTSPServer &&
+    (typeof ZM_MIN_RTSP_PORT !== 'undefined') && !!ZM_MIN_RTSP_PORT;
   this.Go2RTCEnabled = monitorData.Go2RTCEnabled;
   this.Go2RTCMSEBufferCleared = true;
   this.currentChannelStream = null;