Index: ext/fts2/fts2.c
==================================================================
--- ext/fts2/fts2.c
+++ ext/fts2/fts2.c
@@ -3689,11 +3689,11 @@
     dataBufferAppend2(&pWriter->last->data, c, n, pTerm, nTerm);
   }
 }
 
 /* Free the space used by pWriter, including the linked-list of
-** InteriorBlocks.
+** InteriorBlocks, and parentWriter, if present.
 */
 static int interiorWriterDestroy(InteriorWriter *pWriter){
   InteriorBlock *block = pWriter->first;
 
   while( block!=NULL ){
@@ -3700,10 +3700,14 @@
     InteriorBlock *b = block;
     block = block->next;
     dataBufferDestroy(&b->term);
     dataBufferDestroy(&b->data);
     free(b);
+  }
+  if( pWriter->parentWriter!=NULL ){
+    interiorWriterDestroy(pWriter->parentWriter);
+    free(pWriter->parentWriter);
   }
   SCRAMBLE(pWriter);
   return SQLITE_OK;
 }
 
@@ -3841,10 +3845,30 @@
 }
 
 /****************************************************************/
 /* LeafWriter is used to collect terms and associated doclist data
 ** into leaf blocks in %_segments (see top of file for format info).
+** Expected usage is:
+**
+** LeafWriter writer;
+** leafWriterInit(0, 0, &writer);
+** while( sorted_terms_left_to_process ){
+**   // data is doclist data for that term.
+**   rc = leafWriterStep(v, &writer, pTerm, nTerm, pData, nData);
+**   if( rc!=SQLITE_OK ) goto err;
+** }
+** rc = leafWriterFinalize(v, &writer);
+**err:
+** leafWriterDestroy(&writer);
+** return rc;
+**
+** leafWriterStep() may write a collected leaf out to %_segments.
+** leafWriterFinalize() finishes writing any buffered data and stores
+** a root node in %_segdir.  leafWriterDestroy() frees all buffers and
+** InteriorWriters allocated as part of writing this segment.
+**
+** TODO(shess) Document leafWriterStepMerge().
 */
 
 /* Put terms with data this big in their own block. */
 #define STANDALONE_MIN 1024
 
@@ -4877,10 +4901,11 @@
     rc = leafWriterStep(v, &writer,
                         pData[i].pTerm, pData[i].nTerm, dl.pData, dl.nData);
     dlwDestroy(&dlw);
     if( rc!=SQLITE_OK ) goto err;
   }
+  dataBufferDestroy(&dl);
   rc = leafWriterFinalize(v, &writer);
 
  err:
   free(pData);
   leafWriterDestroy(&writer);