Index: src/wherecode.c
==================================================================
--- src/wherecode.c
+++ src/wherecode.c
@@ -512,12 +512,12 @@
     VdbeCoverageIf(v, bRev==0);
     VdbeCoverageIf(v, bRev!=0);
     sqlite3VdbeJumpHere(v, j);
     for(j=0; j<nSkip; j++){
       sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
-      assert( pIdx->aiColumn[j]>=0 );
-      VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName));
+      testcase( pIdx->aiColumn[j]==(-2) );
+      VdbeComment((v, "%s", explainIndexColumnName(pIdx, j)));
     }
   }    
 
   /* Evaluate the equality constraints
   */

Index: test/indexexpr1.test
==================================================================
--- test/indexexpr1.test
+++ test/indexexpr1.test
@@ -215,8 +215,25 @@
 } {001 002 003 004 005}
 do_execsql_test indexexpr1-510eqp {
   EXPLAIN QUERY PLAN
   SELECT substr(a,4,3) AS k FROM cnt, t5 WHERE k=printf('%03d',x);
 } {/USING INDEX t5ax/}
+
+# Skip-scan on an indexed expression
+#
+do_execsql_test indexexpr1-600 {
+  DROP TABLE IF EXISTS t4;
+  CREATE TABLE t4(a,b,c,d,e,f,g,h,i);
+  CREATE INDEX t4all ON t4(a,b,c<d,e,f,i,h);
+  INSERT INTO t4 VALUES(1,2,3,4,5,6,7,8,9);
+  ANALYZE;
+  DELETE FROM sqlite_stat1;
+  INSERT INTO sqlite_stat1
+    VALUES('t4','t4all','600000 160000 40000 10000 2000 600 100 40 10');
+  ANALYZE sqlite_master;
+  SELECT i FROM t4 WHERE e=5;
+} {9}
+
+
 
 
 finish_test