Index: ext/fts5/fts5Int.h
==================================================================
--- ext/fts5/fts5Int.h
+++ ext/fts5/fts5Int.h
@@ -45,10 +45,14 @@
 # define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
 # define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)
 
 #endif
 
+/* Truncate very long tokens to this many bytes. Hard limit is 
+** (65536-1-1-4-9)==65521 bytes. The limiting factor is the 16-bit offset
+** field that occurs at the start of each leaf page (see fts5_index.c). */
+#define FTS5_MAX_TOKEN_SIZE 32768
 
 /*
 ** Maximum number of prefix indexes on single FTS5 table. This must be
 ** less than 32. If it is set to anything large than that, an #error
 ** directive in fts5_index.c will cause the build to fail.

Index: ext/fts5/fts5_expr.c
==================================================================
--- ext/fts5/fts5_expr.c
+++ ext/fts5/fts5_expr.c
@@ -1491,10 +1491,11 @@
 
   UNUSED_PARAM2(iUnused1, iUnused2);
 
   /* If an error has already occurred, this is a no-op */
   if( pCtx->rc!=SQLITE_OK ) return pCtx->rc;
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
 
   if( pPhrase && pPhrase->nTerm>0 && (tflags & FTS5_TOKEN_COLOCATED) ){
     Fts5ExprTerm *pSyn;
     int nByte = sizeof(Fts5ExprTerm) + sizeof(Fts5Buffer) + nToken+1;
     pSyn = (Fts5ExprTerm*)sqlite3_malloc(nByte);
@@ -2493,10 +2494,11 @@
   Fts5Expr *pExpr = p->pExpr;
   int i;
 
   UNUSED_PARAM2(iUnused1, iUnused2);
 
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
   if( (tflags & FTS5_TOKEN_COLOCATED)==0 ) p->iOff++;
   for(i=0; i<pExpr->nPhrase; i++){
     Fts5ExprTerm *pTerm;
     if( p->aPopulator[i].bOk==0 ) continue;
     for(pTerm=&pExpr->apExprPhrase[i]->aTerm[0]; pTerm; pTerm=pTerm->pSynonym){

Index: ext/fts5/fts5_index.c
==================================================================
--- ext/fts5/fts5_index.c
+++ ext/fts5/fts5_index.c
@@ -2318,10 +2318,22 @@
   pIter->iPgidxOff = iPgidx;
 
   fts5SegIterLoadRowid(p, pIter);
   fts5SegIterLoadNPos(p, pIter);
 }
+
+static sqlite3_stmt *fts5IdxSelectStmt(Fts5Index *p){
+  if( p->pIdxSelect==0 ){
+    Fts5Config *pConfig = p->pConfig;
+    fts5IndexPrepareStmt(p, &p->pIdxSelect, sqlite3_mprintf(
+          "SELECT pgno FROM '%q'.'%q_idx' WHERE "
+          "segid=? AND term<=? ORDER BY term DESC LIMIT 1",
+          pConfig->zDb, pConfig->zName
+    ));
+  }
+  return p->pIdxSelect;
+}
 
 /*
 ** Initialize the object pIter to point to term pTerm/nTerm within segment
 ** pSeg. If there is no such term in the index, the iterator is set to EOF.
 **
@@ -2336,35 +2348,29 @@
   Fts5SegIter *pIter              /* Object to populate */
 ){
   int iPg = 1;
   int bGe = (flags & FTS5INDEX_QUERY_SCAN);
   int bDlidx = 0;                 /* True if there is a doclist-index */
+  sqlite3_stmt *pIdxSelect = 0;
 
   assert( bGe==0 || (flags & FTS5INDEX_QUERY_DESC)==0 );
   assert( pTerm && nTerm );
   memset(pIter, 0, sizeof(*pIter));
   pIter->pSeg = pSeg;
 
   /* This block sets stack variable iPg to the leaf page number that may
   ** contain term (pTerm/nTerm), if it is present in the segment. */
-  if( p->pIdxSelect==0 ){
-    Fts5Config *pConfig = p->pConfig;
-    fts5IndexPrepareStmt(p, &p->pIdxSelect, sqlite3_mprintf(
-          "SELECT pgno FROM '%q'.'%q_idx' WHERE "
-          "segid=? AND term<=? ORDER BY term DESC LIMIT 1",
-          pConfig->zDb, pConfig->zName
-    ));
-  }
+  pIdxSelect = fts5IdxSelectStmt(p);
   if( p->rc ) return;
-  sqlite3_bind_int(p->pIdxSelect, 1, pSeg->iSegid);
-  sqlite3_bind_blob(p->pIdxSelect, 2, pTerm, nTerm, SQLITE_STATIC);
-  if( SQLITE_ROW==sqlite3_step(p->pIdxSelect) ){
-    i64 val = sqlite3_column_int(p->pIdxSelect, 0);
+  sqlite3_bind_int(pIdxSelect, 1, pSeg->iSegid);
+  sqlite3_bind_blob(pIdxSelect, 2, pTerm, nTerm, SQLITE_STATIC);
+  if( SQLITE_ROW==sqlite3_step(pIdxSelect) ){
+    i64 val = sqlite3_column_int(pIdxSelect, 0);
     iPg = (int)(val>>1);
     bDlidx = (val & 0x0001);
   }
-  p->rc = sqlite3_reset(p->pIdxSelect);
+  p->rc = sqlite3_reset(pIdxSelect);
 
   if( iPg<pSeg->pgnoFirst ){
     iPg = pSeg->pgnoFirst;
     bDlidx = 0;
   }
@@ -3550,10 +3556,22 @@
         for(iSeg=0; iSeg<pStruct->aLevel[iLvl].nSeg; iSeg++){
           assert( iSegid!=pStruct->aLevel[iLvl].aSeg[iSeg].iSegid );
         }
       }
       assert( iSegid>0 && iSegid<=FTS5_MAX_SEGMENT );
+
+      {
+        sqlite3_stmt *pIdxSelect = fts5IdxSelectStmt(p);
+        if( p->rc==SQLITE_OK ){
+          int rc;
+          u8 aBlob[2] = {0xff, 0xff};
+          sqlite3_bind_int(pIdxSelect, 1, iSegid);
+          sqlite3_bind_blob(pIdxSelect, 2, aBlob, 2, SQLITE_STATIC);
+          assert( sqlite3_step(pIdxSelect)!=SQLITE_ROW );
+          p->rc = sqlite3_reset(pIdxSelect);
+        }
+      }
 #endif
     }
   }
 
   return iSegid;
@@ -3795,10 +3813,13 @@
 
 static void fts5WriteFlushLeaf(Fts5Index *p, Fts5SegWriter *pWriter){
   static const u8 zero[] = { 0x00, 0x00, 0x00, 0x00 };
   Fts5PageWriter *pPage = &pWriter->writer;
   i64 iRowid;
+
+static int nCall = 0;
+nCall++;
 
   assert( (pPage->pgidx.n==0)==(pWriter->bFirstTermInPage) );
 
   /* Set the szLeaf header field. */
   assert( 0==fts5GetU16(&pPage->buf.p[2]) );

Index: ext/fts5/fts5_storage.c
==================================================================
--- ext/fts5/fts5_storage.c
+++ ext/fts5/fts5_storage.c
@@ -367,10 +367,11 @@
   int iUnused2                    /* End offset of token */
 ){
   Fts5InsertCtx *pCtx = (Fts5InsertCtx*)pContext;
   Fts5Index *pIdx = pCtx->pStorage->pIndex;
   UNUSED_PARAM2(iUnused1, iUnused2);
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
   if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
     pCtx->szCol++;
   }
   return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, pCtx->szCol-1, pToken, nToken);
 }
@@ -813,10 +814,11 @@
   int rc = SQLITE_OK;
   int iPos;
   int iCol;
 
   UNUSED_PARAM2(iUnused1, iUnused2);
+  if( nToken>FTS5_MAX_TOKEN_SIZE ) nToken = FTS5_MAX_TOKEN_SIZE;
 
   if( (tflags & FTS5_TOKEN_COLOCATED)==0 || pCtx->szCol==0 ){
     pCtx->szCol++;
   }
 

Index: ext/fts5/test/fts5simple.test
==================================================================
--- ext/fts5/test/fts5simple.test
+++ ext/fts5/test/fts5simple.test
@@ -445,7 +445,27 @@
 } {}
 do_execsql_test 20.2 {
   INSERT INTO x1(x1) VALUES('optimize');
   INSERT INTO x1(x1) VALUES('integrity-check');
 } {}
+
+#-------------------------------------------------------------------------
+reset_db
+set doc "a b [string repeat x 100000]"
+do_execsql_test 21.0 {
+  CREATE VIRTUAL TABLE x1 USING fts5(x);
+  INSERT INTO x1(rowid, x) VALUES(11111, $doc);
+  INSERT INTO x1(rowid, x) VALUES(11112, $doc);
+}
+do_execsql_test 21.1 {
+  INSERT INTO x1(x1) VALUES('integrity-check');
+}
+do_execsql_test 21.2 {
+  SELECT rowid FROM x1($doc);
+} {11111 11112}
+do_execsql_test 21.3 {
+  DELETE FROM x1 WHERE rowid=11111;
+  INSERT INTO x1(x1) VALUES('integrity-check');
+  SELECT rowid FROM x1($doc);
+} {11112}
 
 finish_test