bmodels: and a couple of code comments

Signed-off-by: Mattia Rizzolo <mattia@debian.org>

backend/models.py

@@ -824,10 +824,15 @@ class AM(models.Model):
             am.proc_held = []
             ams[am] = am
 
+        # loop through open processes and collect the AM status of each
         for p in pmodels.AMAssignment.objects.filter(
-                unassigned_by__isnull=True, process__frozen_by__isnull=True,
-                process__approved_by__isnull=True,
-                process__closed_time__isnull=True).select_related("am"):
+                    # The process is still open
+                    process__frozen_by__isnull=True,
+                    process__approved_by__isnull=True,
+                    process__closed_time__isnull=True,
+                    # The AM hasn't been unassigned
+                    unassigned_by__isnull=True,
+                ).select_related("am"):
             am = ams[p.am]
             if p.paused:
                 am.proc_held.append(p)