Fix index deletion bug (#3447)

Author: schmidt-sebastian

firebase-firestore/src/main/java/com/google/firebase/firestore/local/SQLiteIndexManager.java

@@ -217,7 +217,7 @@ public void addFieldIndex(FieldIndex index) {
   public void deleteFieldIndex(FieldIndex index) {
     db.execute("DELETE FROM index_configuration WHERE index_id = ?", index.getIndexId());
     db.execute("DELETE FROM index_entries WHERE index_id = ?", index.getIndexId());
-    db.execute("DELETE FROM index_state WHERE index_id = ?", index.getIndexState());
+    db.execute("DELETE FROM index_state WHERE index_id = ?", index.getIndexId());
 
     nextIndexToUpdate.remove(index);
     Map<Integer, FieldIndex> collectionIndices = memoizedIndexes.get(index.getCollectionGroup());

firebase-firestore/src/test/java/com/google/firebase/firestore/local/SQLiteIndexManagerTest.java

@@ -651,6 +651,21 @@ public void testDeleteFieldIndexRemovesEntryFromCollectionGroup() {
     assertEquals("coll2", collectionGroup);
   }
 
+  @Test
+  public void testDeleteFieldIndexRemovesAllMetadata() {
+    indexManager.addFieldIndex(
+        fieldIndex("coll", 1, IndexState.create(1, IndexOffset.NONE), "value", Kind.ASCENDING));
+    addDoc("coll/doc", map("value", 1));
+    indexManager.updateCollectionGroup("coll", IndexOffset.NONE);
+
+    validateRowCount(1);
+
+    FieldIndex existingIndex = indexManager.getFieldIndexes("coll").iterator().next();
+    indexManager.deleteFieldIndex(existingIndex);
+
+    validateRowCount(0);
+  }
+
   @Test
   public void testChangeUser() {
     IndexManager indexManager = persistence.getIndexManager(User.UNAUTHENTICATED);
@@ -714,4 +729,21 @@ private void verifyResults(Query query, String... documents) {
     List<DocumentKey> keys = Arrays.stream(documents).map(s -> key(s)).collect(Collectors.toList());
     assertWithMessage("Result for %s", query).that(results).containsExactlyElementsIn(keys);
   }
+
+  /** Validates the row count in the SQLite tables that are used for indexing. */
+  private void validateRowCount(int expectedRows) {
+    SQLitePersistence persistence = (SQLitePersistence) this.persistence;
+    persistence
+        .query(
+            "SELECT "
+                + "(SELECT COUNT(*) FROM index_state) AS index_state_count, "
+                + "(SELECT COUNT(*) FROM index_entries) AS index_entries_count, "
+                + "(SELECT COUNT(*) FROM index_configuration) AS index_configuration_count")
+        .first(
+            value -> {
+              assertEquals(value.getInt(0), expectedRows);
+              assertEquals(value.getInt(1), expectedRows);
+              assertEquals(value.getInt(2), expectedRows);
+            });
+  }
 }