fix(dash-spv): re-open committed ranges for gap-limit scripts derived after commit (#846)

dash-spv/src/sync/filters/batch.rs

@@ -69,6 +69,12 @@ impl FiltersBatch {
     pub(super) fn filters_mut(&mut self) -> &mut HashMap<FilterMatchKey, BlockFilter> {
         &mut self.filters
     }
+    /// Take the loaded filters out of this batch, leaving it empty. Used at
+    /// commit to move a committed batch's filters into the manager's retained
+    /// committed-filter set without cloning.
+    pub(super) fn take_filters(&mut self) -> HashMap<FilterMatchKey, BlockFilter> {
+        std::mem::take(&mut self.filters)
+    }
     /// Returns whether this batch is verified (filters verified against their headers).
     pub(super) fn verified(&self) -> bool {
         self.verified

dash-spv/src/sync/filters/block_match_tracker.rs

@@ -153,6 +153,14 @@ impl BlockMatchTracker {
         self.blocks_remaining.is_empty() && self.processed_blocks_per_wallet.is_empty()
     }
 
+    /// True while any matched block is still awaiting its `BlockProcessed`.
+    /// Used to hold off `FiltersSyncComplete` while a committed-range re-open
+    /// (issue #846) has a below-frontier block in flight that no active batch
+    /// accounts for.
+    pub(super) fn has_in_flight(&self) -> bool {
+        !self.blocks_remaining.is_empty()
+    }
+
     /// Drop all in-flight and processed-record state.
     pub(super) fn clear(&mut self) {
         self.blocks_remaining.clear();