Index: ext/fts3/fts3_write.c
==================================================================
--- ext/fts3/fts3_write.c
+++ ext/fts3/fts3_write.c
@@ -4280,14 +4280,17 @@
         pWriter->aNodeWriter[i].iBlock = pWriter->iStart + i*pWriter->nLeafEst;
       }
 
       pNode = &pWriter->aNodeWriter[nHeight];
       pNode->iBlock = pWriter->iStart + pWriter->nLeafEst*nHeight;
-      blobGrowBuffer(&pNode->block, MAX(nRoot, p->nNodeSize), &rc);
+      blobGrowBuffer(&pNode->block, 
+          MAX(nRoot, p->nNodeSize)+FTS3_NODE_PADDING, &rc
+      );
       if( rc==SQLITE_OK ){
         memcpy(pNode->block.a, aRoot, nRoot);
         pNode->block.n = nRoot;
+        memset(&pNode->block.a[nRoot], 0, FTS3_NODE_PADDING);
       }
 
       for(i=nHeight; i>=0 && rc==SQLITE_OK; i--){
         NodeReader reader;
         pNode = &pWriter->aNodeWriter[i];
@@ -4303,14 +4306,17 @@
               char *aBlock = 0;
               int nBlock = 0;
               pNode = &pWriter->aNodeWriter[i-1];
               pNode->iBlock = reader.iChild;
               rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
-              blobGrowBuffer(&pNode->block, MAX(nBlock, p->nNodeSize), &rc);
+              blobGrowBuffer(&pNode->block, 
+                  MAX(nBlock, p->nNodeSize)+FTS3_NODE_PADDING, &rc
+              );
               if( rc==SQLITE_OK ){
                 memcpy(pNode->block.a, aBlock, nBlock);
                 pNode->block.n = nBlock;
+                memset(&pNode->block.a[nBlock], 0, FTS3_NODE_PADDING);
               }
               sqlite3_free(aBlock);
             }
           }
         }