Index: ext/fts3/fts3.c
==================================================================
--- ext/fts3/fts3.c
+++ ext/fts3/fts3.c
@@ -1408,14 +1408,11 @@
 
   /* Check to see if a legacy fts3 table has been "upgraded" by the
   ** addition of a %_stat table so that it can use incremental merge.
   */
   if( !isFts4 && !isCreate ){
-    int rc2 = SQLITE_OK;
-    fts3DbExec(&rc2, db, "SELECT 1 FROM %Q.'%q_stat' WHERE id=2",
-               p->zDb, p->zName);
-    if( rc2==SQLITE_OK ) p->bHasStat = 1;
+    p->bHasStat = 2;
   }
 
   /* Figure out the page-size for the database. This is required in order to
   ** estimate the cost of loading large doclists from the database.  */
   fts3DatabasePageSize(&rc, p);
@@ -3318,11 +3315,38 @@
   sqlite3Fts3SegmentsClose(p);
   return rc;
 }
 
 /*
-** Implementation of xBegin() method. This is a no-op.
+** If it is currently unknown whether or not the FTS table has an %_stat
+** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat
+** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code
+** if an error occurs.
+*/
+static int fts3SetHasStat(Fts3Table *p){
+  int rc = SQLITE_OK;
+  if( p->bHasStat==2 ){
+    const char *zFmt ="SELECT 1 FROM %Q.sqlite_master WHERE tbl_name='%q_stat'";
+    char *zSql = sqlite3_mprintf(zFmt, p->zDb, p->zName);
+    if( zSql ){
+      sqlite3_stmt *pStmt = 0;
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      if( rc==SQLITE_OK ){
+        int bHasStat = (sqlite3_step(pStmt)==SQLITE_ROW);
+        rc = sqlite3_finalize(pStmt);
+        if( rc==SQLITE_OK ) p->bHasStat = bHasStat;
+      }
+      sqlite3_free(zSql);
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  return rc;
+}
+
+/*
+** Implementation of xBegin() method. 
 */
 static int fts3BeginMethod(sqlite3_vtab *pVtab){
   Fts3Table *p = (Fts3Table*)pVtab;
   UNUSED_PARAMETER(pVtab);
   assert( p->pSegments==0 );
@@ -3329,11 +3353,11 @@
   assert( p->nPendingData==0 );
   assert( p->inTransaction!=1 );
   TESTONLY( p->inTransaction = 1 );
   TESTONLY( p->mxSavepoint = -1; );
   p->nLeafAdd = 0;
-  return SQLITE_OK;
+  return fts3SetHasStat(p);
 }
 
 /*
 ** Implementation of xCommit() method. This is a no-op. The contents of
 ** the pending-terms hash-table have already been flushed into the database
@@ -3578,18 +3602,24 @@
 ){
   Fts3Table *p = (Fts3Table *)pVtab;
   sqlite3 *db = p->db;            /* Database connection */
   int rc;                         /* Return Code */
 
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  rc = fts3SetHasStat(p);
+  
   /* As it happens, the pending terms table is always empty here. This is
   ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction 
   ** always opens a savepoint transaction. And the xSavepoint() method 
   ** flushes the pending terms table. But leave the (no-op) call to
   ** PendingTermsFlush() in in case that changes.
   */
   assert( p->nPendingData==0 );
-  rc = sqlite3Fts3PendingTermsFlush(p);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3PendingTermsFlush(p);
+  }
 
   if( p->zContentTbl==0 ){
     fts3DbExec(&rc, db,
       "ALTER TABLE %Q.'%q_content'  RENAME TO '%q_content';",
       p->zDb, p->zName, zName

Index: ext/fts3/fts3Int.h
==================================================================
--- ext/fts3/fts3Int.h
+++ ext/fts3/fts3Int.h
@@ -221,11 +221,11 @@
   char *zReadExprlist;
   char *zWriteExprlist;
 
   int nNodeSize;                  /* Soft limit for node size */
   u8 bFts4;                       /* True for FTS4, false for FTS3 */
-  u8 bHasStat;                    /* True if %_stat table exists */
+  u8 bHasStat;                    /* True if %_stat table exists (2==unknown) */
   u8 bHasDocsize;                 /* True if %_docsize table exists */
   u8 bDescIdx;                    /* True if doclists are in reverse order */
   u8 bIgnoreSavepoint;            /* True to ignore xSavepoint invocations */
   int nPgsz;                      /* Page size for host database */
   char *zSegmentsTbl;             /* Name of %_segments table */

Index: ext/fts3/fts3_write.c
==================================================================
--- ext/fts3/fts3_write.c
+++ ext/fts3/fts3_write.c
@@ -5268,10 +5268,14 @@
   int isRemove = 0;               /* True for an UPDATE or DELETE */
   u32 *aSzIns = 0;                /* Sizes of inserted documents */
   u32 *aSzDel = 0;                /* Sizes of deleted documents */
   int nChng = 0;                  /* Net change in number of documents */
   int bInsertDone = 0;
+
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  assert( p->bHasStat==0 || p->bHasStat==1 );
 
   assert( p->pSegments==0 );
   assert( 
       nArg==1                     /* DELETE operations */
    || nArg==(2 + p->nColumn + 3)  /* INSERT or UPDATE operations */

Index: test/fts3d.test
==================================================================
--- test/fts3d.test
+++ test/fts3d.test
@@ -352,8 +352,19 @@
   db eval {
     ALTER TABLE fts RENAME TO xyz;
     SELECT name FROM sqlite_master WHERE name GLOB '???_*' ORDER BY 1;
   }
 } {xyz_content xyz_segdir xyz_segments}
+
+# ALTER TABLE RENAME on an FTS3 table following an incr-merge op.
+#
+do_test fts3d-6.6 {
+  execsql { INSERT INTO xyz(xyz) VALUES('merge=2,2') }
+  sqlite3 db test.db
+  execsql { 
+    ALTER TABLE xyz RENAME TO ott;
+    SELECT name FROM sqlite_master WHERE name GLOB '???_*' ORDER BY 1;
+  }
+} {ott_content ott_segdir ott_segments ott_stat}
  
 
 finish_test