Fix post-reload trigger.

CHANGES.md

@@ -35,6 +35,9 @@ Maintenance release.
 
 ### Fixes
 
+[#5104](https://github.com/cylc/cylc-flow/pull/5104) - Fix retriggering of
+failed tasks after a reload.
+
 [#5119](https://github.com/cylc/cylc-flow/pull/5119) - Fix formatting of
 deprecation warnings at validation.
 

cylc/flow/task_job_mgr.py

@@ -767,7 +767,10 @@ def _manip_task_jobs_callback(
         tasks = {}
         for itask in itasks:
             while itask.reload_successor is not None:
+                # Note submit number could be incremented since reload.
+                subnum = itask.submit_num
                 itask = itask.reload_successor
+                itask.submit_num = subnum
             if itask.point is not None and itask.submit_num:
                 submit_num = "%02d" % (itask.submit_num)
                 tasks[(str(itask.point), itask.tdef.name, submit_num)] = itask

cylc/flow/task_pool.py

@@ -153,14 +153,10 @@ def stop_task_done(self):
 
     def _swap_out(self, itask):
         """Swap old task for new, during reload."""
-        if itask.point in self.hidden_pool:
-            if itask.identity in self.hidden_pool[itask.point]:
-                self.hidden_pool[itask.point][itask.identity] = itask
-                self.hidden_pool_changed = True
-        elif (
-            itask.point in self.main_pool
-            and itask.identity in self.main_pool[itask.point]
-        ):
+        if itask.identity in self.hidden_pool.get(itask.point, set()):
+            self.hidden_pool[itask.point][itask.identity] = itask
+            self.hidden_pool_changed = True
+        elif itask.identity in self.main_pool.get(itask.point, set()):
             self.main_pool[itask.point][itask.identity] = itask
             self.main_pool_changed = True
 

tests/functional/reload/27-stall-retrigger.t

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#-------------------------------------------------------------------------------
+
+# Test retriggering a failed task after fixing the bug and reloading.
+# It should run correctly with the updated settings.
+
+# https://github.com/cylc/cylc-flow/issues/5103
+
+. "$(dirname "$0")/test_header"
+set_test_number 2
+reftest

tests/functional/reload/27-stall-retrigger/bin/stall-handler.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Change "script = false" -> "true" in 1/foo, then reload and retrigger it.
+
+if grep "\[command\] reload_workflow" "${CYLC_WORKFLOW_LOG_DIR}/log" >/dev/null; then
+    # Abort if not the first call (avoid an endless loop if the reload does not
+    # have the intended effect).
+    cylc stop --now --now "${CYLC_WORKFLOW_ID}"
+    exit 1
+fi
+sed -i "s/false/true/" "${CYLC_WORKFLOW_RUN_DIR}/flow.cylc"
+cylc reload "${CYLC_WORKFLOW_ID}"
+cylc trigger "${CYLC_WORKFLOW_ID}//1/foo"

tests/functional/reload/27-stall-retrigger/flow.cylc

@@ -0,0 +1,13 @@
+# Use a stall handler to fix and reload the workflow config, then retrigger the
+# failed task, which should run successfully with the new settings.
+[scheduler]
+   [[events]]
+       stall handlers = stall-handler.sh
+       expected task failures = 1/foo
+[scheduling]
+    [[graph]]
+        R1 = "foo => bar"
+[runtime]
+    [[foo]]
+        script = false
+    [[bar]]

tests/functional/reload/27-stall-retrigger/reference.log

@@ -0,0 +1,3 @@
+1/foo -triggered off [] in flow 1
+1/foo -triggered off [] in flow 1
+1/bar -triggered off ['1/foo'] in flow 1