Add test of range clear vs set

fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/provider/foundationdb/FDBRecordStore.java

@@ -4706,6 +4706,7 @@ private void maybeLogIndexesNeedingRebuilding(@Nonnull Map<Index, CompletableFut
     @SuppressWarnings("PMD.CloseResource")
     void clearIndexData(@Nonnull Index index) {
         context.clear(Range.startsWith(indexSubspace(index).pack())); // startsWith to handle ungrouped aggregate indexes
+        // clearIndexData clears the secondary index with:
         context.clear(indexSecondarySubspace(index).range());
         IndexingRangeSet.forIndexBuild(this, index).clear();
         // clear even if non-unique in case the index was previously unique

fdb-record-layer-core/src/main/java/com/apple/foundationdb/record/provider/foundationdb/leaderboard/TimeWindowLeaderboardIndexMaintainer.java

@@ -109,6 +109,7 @@ protected CompletableFuture<TimeWindowLeaderboard> oldestLeaderboardMatching(int
     @Nonnull
     protected CompletableFuture<TimeWindowLeaderboardDirectory> loadDirectory() {
         final Subspace extraSubspace = getSecondarySubspace();
+        // TimeWindow Leaderboard sets secondary subspace directly via `subspace.pack()`
         return state.transaction.get(extraSubspace.pack()).thenApply(bytes -> {
             if (bytes == null) {
                 return null;

fdb-record-layer-core/src/test/java/com/apple/foundationdb/record/provider/foundationdb/FDBRecordContextTest.java

@@ -69,6 +69,7 @@
 import static org.hamcrest.Matchers.hasEntry;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.lessThanOrEqualTo;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
@@ -676,6 +677,33 @@ public void contextExecutor() {
         }
     }
 
+    @Test
+    void clearAndRead() {
+        final FDBDatabase database = dbExtension.getDatabase();
+
+        final Subspace subspace = new Subspace(Tuple.from("A", 1, "boo"));
+        final byte[] value = Tuple.from("here").pack();
+        try (FDBRecordContext context = database.openContext()) {
+            context.ensureActive().set(subspace.pack(), value);
+            context.commit();
+        }
+
+
+        try (FDBRecordContext context = database.openContext()) {
+            assertArrayEquals(value, context.ensureActive().get(subspace.pack()).join());
+
+            assertArrayEquals(new byte[] { 0x02, 'A', 0x0, 21, 0x01, 0x02, 'b', 'o', 'o', 0x0}, subspace.pack());
+            assertArrayEquals(new byte[] { 0x02, 'A', 0x0, 21, 0x01, 0x02, 'b', 'o', 'o', 0x0, 0x0}, subspace.range().begin);
+            assertArrayEquals(new byte[] { 0x02, 'A', 0x0, 21, 0x01, 0x02, 'b', 'o', 'o', 0x0, -1}, subspace.range().end);
+
+            context.clear(subspace.range());
+
+            assertNotNull(context.ensureActive().get(subspace.pack()).join()); // <== should this fail
+            context.commit();
+        }
+
+    }
+
     static class ThreadIdRestoringExecutor extends TaskNotifyingExecutor {
         private int threadId;