FastRestore:addPrefix:Transform must clear both orignal and transformed range

Otherwise, anything left in the range can interfer with the result.

fdbclient/RestoreWorkerInterface.actor.h

@@ -257,6 +257,8 @@ struct RestoreAsset {
 		return ss.str();
 	}
 
+	bool hasPrefix() const { return addPrefix.size() > 0 || removePrefix.size() > 0; }
+
 	// RestoreAsset and VersionBatch both use endVersion as exclusive in version range
 	bool isInVersionRange(Version commitVersion) const {
 		return commitVersion >= beginVersion && commitVersion < endVersion;
@@ -264,11 +266,24 @@ struct RestoreAsset {
 
 	// Is mutation's begin and end keys are in RestoreAsset's range
 	bool isInKeyRange(MutationRef mutation) const {
-		if (isRangeMutation(mutation)) {
-			// Range mutation's right side is exclusive
-			return mutation.param1 >= range.begin && mutation.param2 <= range.end;
+		if (hasPrefix()) {
+			Key begin = range.begin; // Avoid creating new keys if we do not have addPrefix or removePrefix
+			Key end = range.end;
+			begin = begin.removePrefix(removePrefix).withPrefix(addPrefix);
+			end = end.removePrefix(removePrefix).withPrefix(addPrefix);
+			if (isRangeMutation(mutation)) {
+				// Range mutation's right side is exclusive
+				return mutation.param1 >= begin && mutation.param2 <= end;
+			} else {
+				return mutation.param1 >= begin && mutation.param1 < end;
+			}
 		} else {
-			return mutation.param1 >= range.begin && mutation.param1 < range.end;
+			if (isRangeMutation(mutation)) {
+				// Range mutation's right side is exclusive
+				return mutation.param1 >= range.begin && mutation.param2 <= range.end;
+			} else {
+				return mutation.param1 >= range.begin && mutation.param1 < range.end;
+			}
 		}
 	}
 };

fdbserver/RestoreApplier.actor.cpp

@@ -147,7 +147,8 @@ ACTOR static Future<Void> handleSendMutationVectorRequest(RestoreSendVersionedMu
 			    isAtomicOp((MutationRef::Type)versionedMutation.mutation.type) ? 1 : 0;
 			// Sanity check
 			ASSERT_WE_THINK(req.asset.isInVersionRange(versionedMutation.version.version));
-			ASSERT_WE_THINK(req.asset.isInKeyRange(versionedMutation.mutation));
+			ASSERT_WE_THINK(req.asset.isInKeyRange(
+			    versionedMutation.mutation)); // mutation is already applied removePrefix and addPrefix
 
 			// Note: Log and range mutations may be delivered out of order. Can we handle it?
 			batchData->addMutation(versionedMutation.mutation, versionedMutation.version);

fdbserver/RestoreLoader.actor.cpp

@@ -793,7 +793,7 @@ void _parseSerializedMutation(KeyRangeMap<Version>* pRangeVersions,
 			    (!isRangeMutation(mutation) && mutation.param1 < asset.range.begin)) {
 				continue;
 			}
-			// Only apply mutation within the asset.range
+			// Only apply mutation within the asset.range and apply removePrefix and addPrefix
 			if (isRangeMutation(mutation)) {
 				mutation.param1 = mutation.param1 >= asset.range.begin ? mutation.param1 : asset.range.begin;
 				mutation.param2 = mutation.param2 < asset.range.end ? mutation.param2 : asset.range.end;

fdbserver/workloads/BackupAndParallelRestoreCorrectness.actor.cpp

@@ -381,7 +381,10 @@ struct BackupAndParallelRestoreCorrectnessWorkload : TestWorkload {
 			tr->setOption(FDBTransactionOptions::LOCK_AWARE);
 			for (auto& range : restoreRanges) {
 				TraceEvent("TransformDatabaseContents").detail("Clear", range);
-				tr->clear(range); // Careful when we restore only a sub key range!
+				tr->clear(range); // Clear the range.removePrefix().withPrefix()
+				KeyRange newRange = range;
+				newRange = newRange.removePrefix(removePrefix).withPrefix(addPrefix); // Clear dest. range
+				tr->clear(newRange);
 			}
 			return Void();
 		}));