Delete the duplicate sprout key during an upgrade.

zebra-state/src/service/finalized_state/disk_format/upgrade.rs

@@ -291,8 +291,12 @@ impl DbFormatChange {
 
             // Writing the trees back to the database automatically caches their roots.
             let mut batch = DiskWriteBatch::new();
+            // Delete the previous `Height` tip key format, which is now a duplicate.
+            // It's ok to do a full delete, because the trees are restored later in the batch.
+            batch.delete_range_sprout_tree(&db, &Height(0), &Height::MAX);
             // Fix the cached root of the Sprout genesis tree in its anchors column family.
-            // The genesis update to the tip tree is overwritten by the actual tip in the batch.
+            // It's ok to write the genesis tree to the tip tree index, because is overwritten by
+            // the actual tip later in the batch.
             batch.update_sprout_tree(&db, &sprout_genesis_tree);
             // Update the sprout tip key format in the database.
             batch.update_sprout_tree(&db, &sprout_tip_tree);

zebra-state/src/service/finalized_state/zebra_db/shielded.rs

@@ -400,6 +400,18 @@ impl DiskWriteBatch {
         self.zs_insert(&orchard_tree_cf, height, tree);
     }
 
+    /// Deletes the range of Sprout note commitment trees at the given [`Height`]s.
+    /// Doesn't delete anchors from the anchor index. Doesn't delete the upper bound.
+    pub fn delete_range_sprout_tree(&mut self, zebra_db: &ZebraDb, from: &Height, to: &Height) {
+        let sprout_tree_cf = zebra_db
+            .db
+            .cf_handle("sprout_note_commitment_tree")
+            .unwrap();
+
+        // TODO: convert zs_delete_range() to take std::ops::RangeBounds
+        self.zs_delete_range(&sprout_tree_cf, from, to);
+    }
+
     /// Deletes the Sapling note commitment tree at the given [`Height`].
     pub fn delete_sapling_tree(&mut self, zebra_db: &ZebraDb, height: &Height) {
         let sapling_tree_cf = zebra_db
@@ -409,7 +421,8 @@ impl DiskWriteBatch {
         self.zs_delete(&sapling_tree_cf, height);
     }
 
-    /// Deletes the range of Sapling note commitment trees at the given [`Height`]s. Doesn't delete the upper bound.
+    /// Deletes the range of Sapling note commitment trees at the given [`Height`]s.
+    /// Doesn't delete anchors from the anchor index. Doesn't delete the upper bound.
     #[allow(dead_code)]
     pub fn delete_range_sapling_tree(&mut self, zebra_db: &ZebraDb, from: &Height, to: &Height) {
         let sapling_tree_cf = zebra_db
@@ -430,7 +443,8 @@ impl DiskWriteBatch {
         self.zs_delete(&orchard_tree_cf, height);
     }
 
-    /// Deletes the range of Orchard note commitment trees at the given [`Height`]s. Doesn't delete the upper bound.
+    /// Deletes the range of Orchard note commitment trees at the given [`Height`]s.
+    /// Doesn't delete anchors from the anchor index. Doesn't delete the upper bound.
     #[allow(dead_code)]
     pub fn delete_range_orchard_tree(&mut self, zebra_db: &ZebraDb, from: &Height, to: &Height) {
         let orchard_tree_cf = zebra_db