catch attempts to save a fact that deletes a cloze card

anki/facts.py

@@ -45,6 +45,8 @@ from facts where id = ?""", self.id)
         self._fmap = self.deck.models.fieldMap(self._model)
 
     def flush(self, mod=None):
+        if self.model()['cloze']:
+            self._clozeFlush()
         self.mod = mod if mod else intTime()
         self.usn = self.deck.usn()
         sfld = stripHTML(self.fields[self.deck.models.sortIdx(self._model)])
@@ -177,3 +179,25 @@ insert or replace into facts values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""",
             else:
                 d.append((ord, None))
         return [x[1] for x in sorted(d)]
+
+    # Flushing cloze facts
+    ##################################################
+
+    def _clozeFlush(self):
+        tmpls = self.deck.findTemplates(self)
+        ok = []
+        for t in tmpls:
+            ok.append(t['ord'])
+        # check if there are cards referencing a deleted cloze
+        if self.deck.db.scalar(
+            "select 1 from cards where fid = ? and ord not in %s" %
+            ids2str(ok), self.id):
+            # there are; abort, as the UI should have handled this
+            raise Exception("UI should have deleted cloze")
+        # generate missing cards
+        # for t in tmpls:
+        #     if not self.deck.db.scalar(
+        #         "select 1 from cards where fid = ? and ord = ?",
+        #         self.id, t['ord']):
+        #         add.append(t)
+        #     have = self.deck.db.scalar(

anki/models.py

@@ -437,10 +437,14 @@ select id from facts where mid = ?)""" % " ".join(map),
     def _updateRequired(self, m):
         req = []
         flds = [f['name'] for f in m['flds']]
+        cloze = False
         for t in m['tmpls']:
             ret = self._reqForTemplate(m, flds, t)
+            if ret[1]:
+                cloze = True
             req.append((t['ord'], ret[0], ret[1]))
         m['req'] = req
+        m['cloze'] = cloze
 
     def _reqForTemplate(self, m, flds, t):
         a = []

tests/test_models.py

@@ -1,6 +1,6 @@
 # coding: utf-8
 
-from tests.shared import getEmptyDeck
+from tests.shared import getEmptyDeck, assertException
 from anki.utils import stripHTML
 
 def test_modelDelete():
@@ -164,6 +164,11 @@ def test_cloze():
     assert d.addFact(f) == 0
     f['Text'] = "hello {{c1::foo}}"
     assert d.addFact(f) == 1
+    # deleting a cloze should fail; the ui should clean up invalid cards
+    f['Text'] = "hello"
+    assertException(Exception, lambda: f.flush())
+
+
 
 def test_modelChange():
     deck = getEmptyDeck()