Index: ext/expert/expert1.test
==================================================================
--- ext/expert/expert1.test
+++ ext/expert/expert1.test
@@ -289,10 +289,19 @@
 } {
   CREATE INDEX t2_idx_00000064 ON t2(d);
   0|0|0|SEARCH TABLE t2 USING INDEX t2_idx_00000064 (d=?) 
   0|1|1|SEARCH TABLE t1 USING INTEGER PRIMARY KEY (rowid=?)
 }
+
+do_setup_rec_test $tn.16 {
+  CREATE TABLE t1(a, b);
+} {
+  SELECT * FROM t1 WHERE b IS NOT NULL;
+} {
+  (no new indexes)
+  0|0|0|SCAN TABLE t1
+}
 
 }
 
 proc do_candidates_test {tn sql res} {
   set res [squish [string trim $res]]

Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -3158,13 +3158,16 @@
 */
 const char *sqlite3_vtab_collation(sqlite3 *db, int iCons){
   struct BestIndexCtx *p = (struct BestIndexCtx*)db->pBestIndexCtx;
   const char *zRet = 0;
   if( p && iCons>=0 && iCons<p->pIdxInfo->nConstraint ){
+    CollSeq *pC = 0;
     int iTerm = p->pIdxInfo->aConstraint[iCons].iTermOffset;
     Expr *pX = p->pWC->a[iTerm].pExpr;
-    CollSeq *pC = sqlite3BinaryCompareCollSeq(p->pParse,pX->pLeft,pX->pRight);
+    if( pX->pLeft ){
+      pC = sqlite3BinaryCompareCollSeq(p->pParse, pX->pLeft, pX->pRight);
+    }
     zRet = (pC ? pC->zName : "BINARY");
   }
   return zRet;
 }