From 8497da27cf47f395a8288c47d9ff3ba32e95cfc4 Mon Sep 17 00:00:00 2001
From: Damien Elmes <gpg@ankiweb.net>
Date: Sun, 21 Apr 2019 18:02:12 +1000
Subject: [PATCH] ensure the list of note types is not empty

fixes an issue opening the add screen if a user manages to delete
all their note types with an add-on or a sync
---
 anki/collection.py | 3 +++
 anki/models.py     | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/anki/collection.py b/anki/collection.py
index 60ac01441..c9f93618a 100644
--- a/anki/collection.py
+++ b/anki/collection.py
@@ -872,6 +872,9 @@ and type = 0""", intTime(), self.usn())
         curs.execute("update revlog set ivl=round(ivl),lastIvl=round(lastIvl) where ivl!=round(ivl) or lastIvl!=round(lastIvl)")
         if curs.rowcount:
             problems.append("Fixed %d review history entries with v2 scheduler bug." % curs.rowcount)
+        # models
+        if self.models.ensureNotEmpty():
+            problems.append("Added missing note type.")
         # and finally, optimize
         self.optimize()
         newSize = os.stat(self.path)[stat.ST_SIZE]
diff --git a/anki/models.py b/anki/models.py
index 9da5822bb..d37b7e24e 100644
--- a/anki/models.py
+++ b/anki/models.py
@@ -96,10 +96,17 @@ class ModelManager:
     def flush(self):
         "Flush the registry if any models were changed."
         if self.changed:
+            self.ensureNotEmpty()
             self.col.db.execute("update col set models = ?",
                                  json.dumps(self.models))
             self.changed = False
 
+    def ensureNotEmpty(self):
+        if not self.models:
+            from anki.stdmodels import addBasicModel
+            addBasicModel(self.col)
+            return True
+
     # Retrieving and creating models
     #############################################################