Accept only one approval per run

This change includes:
* fix for multiple approvals that overwrite the approver in the Events
* get the run only once

server/fishtest/rundb.py

@@ -1316,15 +1316,20 @@ def stop_run(self, run_id):
 
     def approve_run(self, run_id, approver):
         run = self.get_run(run_id)
+        if run is None:
+            return None, "Run not found!"
         # Can't self approve
         if run["args"]["username"] == approver:
-            return False
-
-        run["approved"] = True
-        run["approver"] = approver
-        self.buffer(run, True)
-        self.task_time = 0
-        return True
+            return None, "Self approval is disabled!"
+        # Only one approval per run
+        if not run["approved"]:
+            run["approved"] = True
+            run["approver"] = approver
+            self.buffer(run, True)
+            self.task_time = 0
+            return run, "Run approved"
+        else:
+            return None, "Run already approved!"
 
     def purge_run(self, run, p=0.001, res=7.0, iters=1):
         # Only purge finished runs

server/fishtest/views.py

@@ -1079,16 +1079,13 @@ def tests_approve(request):
         return HTTPFound(location=request.route_url("login"))
     username = request.authenticated_userid
     run_id = request.POST["run-id"]
-    if request.rundb.approve_run(run_id, username):
-        run = request.rundb.get_run(run_id)
-        update_nets(request, run)
-        request.actiondb.approve_run(
-            username=username,
-            run=run,
-        )
-        cached_flash(request, "Approved run")
+    run, message = request.rundb.approve_run(run_id, username)
+    if run is None:
+        request.session.flash(message, "error")
     else:
-        request.session.flash("Unable to approve run!", "error")
+        update_nets(request, run)
+        request.actiondb.approve_run(username=username, run=run)
+        cached_flash(request, message)
     return HTTPFound(location=request.route_url("tests"))