Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -5907,11 +5907,11 @@
   if( pWInfo->nLevel>=2
    && pResultSet!=0
    && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
   ){
     Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
-    if( pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, pOrderBy);
+    if( sWLB.pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, sWLB.pOrderBy);
     while( pWInfo->nLevel>=2 ){
       WhereTerm *pTerm, *pEnd;
       pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
       if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break;
       if( (wctrlFlags & WHERE_WANT_DISTINCT)==0

Index: test/where.test
==================================================================
--- test/where.test
+++ test/where.test
@@ -1301,7 +1301,36 @@
     CREATE TABLE tother(a, b);
     INSERT INTO tother VALUES(1, 3.7);
     SELECT id, a FROM tbooking, tother WHERE id>a;
   }
 } {42 1 43 1}
+
+# Ticket [be84e357c035d068135f20bcfe82761bbf95006b]  2013-09-03
+# Segfault during query involving LEFT JOIN column in the ORDER BY clause.
+#
+do_execsql_test where-18.1 {
+  CREATE TABLE t181(a);
+  CREATE TABLE t182(b,c);
+  INSERT INTO t181 VALUES(1);
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY c IS NULL;
+} {1}
+do_execsql_test where-18.2 {
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY +c;
+} {1}
+do_execsql_test where-18.3 {
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY c;
+} {1}
+do_execsql_test where-18.4 {
+  INSERT INTO t181 VALUES(1),(1),(1),(1);
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY +c;
+} {1}
+do_execsql_test where-18.5 {
+  INSERT INTO t181 VALUES(2);
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY c IS NULL, +a;
+} {1 2}
+do_execsql_test where-18.6 {
+  INSERT INTO t181 VALUES(2);
+  SELECT DISTINCT a FROM t181 LEFT JOIN t182 ON a=b ORDER BY +a, +c IS NULL;
+} {1 2}
+
 
 finish_test