Fix VersionInfo SelVector creation (#4556)

One branch of the code was setting the existing SelectionVector to filtered and then appending to it
Existing unfiltered elements would be discarded and replaced with whatever happened to be in the SelectionVector's mutable buffer

src/include/common/data_chunk/sel_vector.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <string.h>
+
 #include <memory>
 
 #include "common/constants.h"
@@ -58,6 +60,13 @@ class SelectionVector {
         selectedSize = size;
     }
 
+    // Copies the data in selectedPositions into selectedPositionsBuffer
+    void makeDynamic() {
+        memcpy(selectedPositionsBuffer.get(), selectedPositions, selectedSize * sizeof(sel_t));
+        state = State::DYNAMIC;
+        selectedPositions = selectedPositionsBuffer.get();
+    }
+
     std::span<sel_t> getMutableBuffer() const {
         return std::span<sel_t>(selectedPositionsBuffer.get(), capacity);
     }

src/storage/store/version_info.cpp

@@ -100,6 +100,11 @@ void VectorVersionInfo::getSelVectorForScan(const transaction_t startTS,
             selVector.setToFiltered(numSelected);
         }
     } else if (insertionStatus != InsertionStatus::NO_INSERTED) {
+        // If there were no deleted values up to this point the selVector may be unfiltered but have
+        // non-zero size, and the mutable buffer may have arbitrary contents
+        if (selVector.isUnfiltered()) {
+            selVector.makeDynamic();
+        }
         for (auto i = 0u; i < numRows; i++) {
             if (const auto rowIdx = startRow + i; isInserted(startTS, transactionID, rowIdx) &&
                                                   !isDeleted(startTS, transactionID, rowIdx)) {

test/test_files/dml_rel/delete/delete_ldbc_sf01.test

@@ -1,9 +1,7 @@
 -DATASET CSV ldbc-sf01
 --
 
-# FIX-ME(Guodong): https://github.com/kuzudb/kuzu/issues/4271
 -CASE DeleteLikeComment1
--SKIP
 -STATEMENT MATCH (n:Person)-[e:likes_Comment]->(m:Comment) WHERE n.id=6597069767457 RETURN COUNT(*);
 ---- 1
 66