pibd: fix check for next required kernel segment

Author: ardocrat

chain/src/txhashset/desegmenter.rs

@@ -479,6 +479,7 @@ impl Desegmenter {
 		let mut return_vec = vec![];
 		// First check for required bitmap elements
 		if self.bitmap_cache.is_none() {
+			debug!("no bitmap cache available");
 			// Get current size of bitmap MMR
 			let local_pmmr_size = self.bitmap_accumulator.readonly_pmmr().unpruned_size();
 			// Get iterator over expected bitmap elements
@@ -498,6 +499,7 @@ impl Desegmenter {
 				}
 			}
 		} else {
+			debug!("bitmap cache available");
 			// We have all required bitmap segments and have recreated our local
 			// bitmap, now continue with other segments, evenly spreading requests
 			// among MMRs
@@ -530,6 +532,10 @@ impl Desegmenter {
 					let (_first, last) =
 						output_id.segment_pos_range(self.archive_header.output_mmr_size);
 					if last > local_output_mmr_size && !self.has_output_segment_with_id(output_id) {
+						debug!(
+							"push 1: {:?}, last: {} local size: {}",
+							output_id, last, local_output_mmr_size
+						);
 						return_vec.push(SegmentTypeIdentifier::new(SegmentType::Output, output_id));
 						elems_added += 1;
 					}
@@ -559,6 +565,10 @@ impl Desegmenter {
 					if last > local_rangeproof_mmr_size
 						&& !self.has_rangeproof_segment_with_id(rp_id)
 					{
+						debug!(
+							"push 2: {:?}. last: {} local size: {}",
+							rp_id, last, local_output_mmr_size
+						);
 						return_vec.push(SegmentTypeIdentifier::new(SegmentType::RangeProof, rp_id));
 						elems_added += 1;
 					}
@@ -586,6 +596,10 @@ impl Desegmenter {
 					let (_first, last) =
 						k_id.segment_pos_range(self.archive_header.kernel_mmr_size);
 					if last > local_kernel_mmr_size && !self.has_kernel_segment_with_id(k_id) {
+						debug!(
+							"push 3: {:?}, last: {} local size: {}",
+							k_id, last, local_output_mmr_size
+						);
 						return_vec.push(SegmentTypeIdentifier::new(SegmentType::Kernel, k_id));
 						elems_added += 1;
 					}
@@ -608,6 +622,7 @@ impl Desegmenter {
 				if return_vec.len() >= max_elements {
 					return_vec.pop();
 				}
+				debug!("push 4: {:?}", seg_id);
 				return_vec.push(next_kernel_seg_id);
 			}
 		}
@@ -1069,17 +1084,24 @@ impl Desegmenter {
 			)
 		};
 
-		// When resuming, we need to ensure we're getting the previous segment if needed
-		let theoretical_pmmr_size =
-			SegmentIdentifier::pmmr_size(cur_segment_count, self.default_kernel_segment_height);
-		if local_kernel_mmr_size < theoretical_pmmr_size {
-			cur_segment_count -= 1;
-		}
-
 		let total_segment_count = SegmentIdentifier::count_segments_required(
 			self.archive_header.kernel_mmr_size,
 			self.default_kernel_segment_height,
 		);
+
+		// When resuming, we need to ensure we're getting the previous segment if needed
+		if total_segment_count != cur_segment_count {
+			let theoretical_pmmr_size =
+				SegmentIdentifier::pmmr_size(cur_segment_count, self.default_kernel_segment_height);
+			if local_kernel_mmr_size < theoretical_pmmr_size {
+				debug!(
+					"theoretical_pmmr_size {} is bigger than the current mmr size {}",
+					theoretical_pmmr_size, local_kernel_mmr_size
+				);
+				cur_segment_count -= 1;
+			}
+		}
+
 		trace!(
 			"Next required kernel segment is {} of {}",
 			cur_segment_count,