Fix missing displays on sesman restart

libipm/ercp.c

@@ -208,10 +208,7 @@ ercp_get_session_announce_event(struct trans *trans,
 
     if (rv == 0)
     {
-        if (display != NULL)
-        {
-            *display = i_display;
-        }
+        *display = i_display;
         *uid = (uid_t)i_uid;
         *type = (enum scp_session_type)i_type;
         *start_width = i_width;

libipm/ercp.h

@@ -188,7 +188,6 @@ ercp_send_session_announce_event(struct trans *trans,
  *
  * @param trans EICP transport
  * @param[out] display Display used by session.
- *             Pointer can be NULL if this is already known.
  * @param[out] uid UID of user logged in to session
  * @param[out] type Session type
  * @param[out] start_width Starting width of seenio

sesman/ercp_process.c

@@ -42,9 +42,10 @@ process_session_announce_event(struct session_item *si)
 {
     int rv;
     const char *start_ip_addr;
+    unsigned int display;
 
     rv = ercp_get_session_announce_event(si->sesexec_trans,
-                                         NULL,
+                                         &display,
                                          &si->uid,
                                          &si->type,
                                          &si->start_width,
@@ -53,10 +54,24 @@ process_session_announce_event(struct session_item *si)
                                          &si->guid,
                                          &start_ip_addr,
                                          &si->start_time);
+    if (rv == 0)
+    {
+        // We may already know the display we sent sesexec. If we do,
+        // check sesexec sent the same value back.
+        if (si->display >= 0 && display != (unsigned int)si->display)
+        {
+            LOG(LOG_LEVEL_ERROR, "Bugcheck: sesman expected display %d, got %u",
+                si->display, display);
+            rv = 1;
+        }
+    }
+
     if (rv == 0)
     {
         snprintf(si->start_ip_addr, sizeof(si->start_ip_addr),
                  "%s", start_ip_addr);
+        si->display = display;
+
         si->state = E_SESSION_RUNNING;
     }