From ddba99bfd8557a46f3231ca05021bc7068c3bec4 Mon Sep 17 00:00:00 2001
From: Athanasius <github@miggy.org>
Date: Wed, 10 Aug 2022 11:28:10 +0100
Subject: [PATCH 1/3] monitor: Handle NavRouteClear & un-() an assert

* Stop trying to load `NavRoute.json` if it contained a `NavRouteClear`.
* `assert` is a *keyword*, not a function.
---
 monitor.py | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/monitor.py b/monitor.py
index eb9fbfb3..859b2a50 100644
--- a/monitor.py
+++ b/monitor.py
@@ -1469,7 +1469,7 @@ class EDLogs(FileSystemEventHandler):  # type: ignore # See below
                                 self.state[category].pop(material)
 
                 module = self.state['Modules'][entry['Slot']]
-                assert(module['Item'] == self.canonicalise(entry['Module']))
+                assert module['Item'] == self.canonicalise(entry['Module'])
                 module['Engineering'] = {
                     'Engineer':      entry['Engineer'],
                     'EngineerID':    entry['EngineerID'],
@@ -2300,9 +2300,15 @@ class EDLogs(FileSystemEventHandler):  # type: ignore # See below
             )
             return False
 
-        # everything is good, lets set what we need to and make sure we dont try again
-        logger.info('Successfully read NavRoute file for last NavRoute event.')
-        self.state['NavRoute'] = file
+        # Handle it being `NavRouteClear`d already
+        if file['event'].lower() == 'navrouteclear':
+            logger.info('NavRoute file contained a NavRouteClear')
+            # We do *NOT* copy into/clear the `self.state['NavRoute']`
+        else:
+            # everything is good, lets set what we need to and make sure we dont try again
+            logger.info('Successfully read NavRoute file for last NavRoute event.')
+            self.state['NavRoute'] = file
+
         self._navroute_retries_remaining = 0
         self._last_navroute_journal_timestamp = None
         return True

From 1bb0bf9f74fcfee2a0b64da036b63a7a92e23af3 Mon Sep 17 00:00:00 2001
From: Athanasius <github@miggy.org>
Date: Wed, 10 Aug 2022 11:47:51 +0100
Subject: [PATCH 2/3] PLUGINS.md: Document `NavRouteClear` behaviour

---
 PLUGINS.md | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/PLUGINS.md b/PLUGINS.md
index b26ee58b..be479920 100644
--- a/PLUGINS.md
+++ b/PLUGINS.md
@@ -698,6 +698,18 @@ New in version 5.1.1:
 `state` now has a `ShipLockerJSON` member containing the un-changed, loaded,
 JSON from the `ShipLockerJSON.json` file.
 
+New in version 5.4.2+:
+
+We now handle the 'Update 13' `NavRouteClear` event by detecting if that's what
+is in the `NavRoute.json` file.  If this is the case then we log that, **but
+do NOT clear `state['NavRoute']`**.  Plugins will get sent the Journal
+`NavRouteClear` event anyway, and there might be some value to them retaining
+access to the prior plotted route.
+
+NB: It *is* possible, if a player is quick enough, to plot and clear a route
+before we load it, in which case we'd be retaining the *previous* plotted
+route.
+
 ___
 
 ##### Synthetic Events

From f28228285a5c6443d71687305f31c4dda3943a67 Mon Sep 17 00:00:00 2001
From: Athanasius <github@miggy.org>
Date: Wed, 10 Aug 2022 11:51:23 +0100
Subject: [PATCH 3/3] plugins/eddn: Do *NOT* alert user on 'no Route in
 NavRoute'

This can simply occur if the *first* load of `NavRoute.json` soft-fails,
meaning the plugin is receiving the bare Journal-file event, which has no
`Route` array.
---
 plugins/eddn.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/plugins/eddn.py b/plugins/eddn.py
index 4bea9bcd..b369e415 100644
--- a/plugins/eddn.py
+++ b/plugins/eddn.py
@@ -1111,8 +1111,10 @@ class EDDN:
         # Sanity check - Ref Issue 1342
         if 'Route' not in entry:
             logger.warning(f"NavRoute didn't contain a Route array!\n{entry!r}")
-            # LANG: No 'Route' found in NavRoute.json file
-            return _("No 'Route' array in NavRoute.json contents")
+            # This can happen if first-load of the file failed, and we're simply
+            # passing through the bare Journal event, so no need to alert
+            # the user.
+            return None
 
         #######################################################################
         # Elisions