Index: ext/rtree/rtreeC.test
==================================================================
--- ext/rtree/rtreeC.test
+++ ext/rtree/rtreeC.test
@@ -105,8 +105,58 @@
   SELECT * FROM t, r_tree
 } {
   0 0 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:}
   0 1 0 {SCAN TABLE t} 
 }
+
+#-------------------------------------------------------------------------
+# Test that the special CROSS JOIN handling works with rtree tables.
+#
+do_execsql_test 3.1 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(y);
+  CREATE VIRTUAL TABLE t3 USING rtree(z, x1,x2, y1,y2);
+}
+
+do_eqp_test 3.2.1 { SELECT * FROM t1 CROSS JOIN t2 } {
+  0 0 0 {SCAN TABLE t1} 
+  0 1 1 {SCAN TABLE t2}
+}
+do_eqp_test 3.2.2 { SELECT * FROM t2 CROSS JOIN t1 } {
+  0 0 0 {SCAN TABLE t2} 0 1 1 {SCAN TABLE t1}
+}
+
+do_eqp_test 3.3.1 { SELECT * FROM t1 CROSS JOIN t3 } {
+  0 0 0 {SCAN TABLE t1}
+  0 1 1 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
+}
+do_eqp_test 3.3.2 { SELECT * FROM t3 CROSS JOIN t1 } {
+  0 0 0 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SCAN TABLE t1}
+}
+
+#--------------------------------------------------------------------
+# Test that LEFT JOINs are not reordered if the right-hand-side is
+# a virtual table.
+#
+reset_db
+do_execsql_test 4.1 {
+  CREATE TABLE t1(a);
+  CREATE VIRTUAL TABLE t2 USING rtree(b, x1,x2);
+
+  INSERT INTO t1 VALUES(1);
+  INSERT INTO t1 VALUES(2);
+
+  INSERT INTO t2 VALUES(1, 0.0, 0.1);
+  INSERT INTO t2 VALUES(3, 0.0, 0.1);
+}
+
+do_execsql_test 4.2 {
+  SELECT a, b FROM t1 LEFT JOIN t2 ON (+a = +b);
+} {1 1 2 {}}
+
+do_execsql_test 4.3 {
+  SELECT b, a FROM t2 LEFT JOIN t1 ON (+a = +b);
+} {1 1 3 {}}
 
 finish_test
 

Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -4700,11 +4700,12 @@
 /*
 ** Add all WhereLoop objects for a table of the join identified by
 ** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
 */
 static int whereLoopAddVirtual(
-  WhereLoopBuilder *pBuilder   /* WHERE clause information */
+  WhereLoopBuilder *pBuilder,  /* WHERE clause information */
+  Bitmask mExtra
 ){
   WhereInfo *pWInfo;           /* WHERE analysis context */
   Parse *pParse;               /* The parsing context */
   WhereClause *pWC;            /* The WHERE clause */
   struct SrcList_item *pSrc;   /* The FROM clause term to search */
@@ -4790,11 +4791,11 @@
     pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
     pIdxInfo->estimatedRows = 25;
     rc = vtabBestIndex(pParse, pTab, pIdxInfo);
     if( rc ) goto whereLoopAddVtab_exit;
     pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-    pNew->prereq = 0;
+    pNew->prereq = mExtra;
     mxTerm = -1;
     assert( pNew->nLSlot>=nConstraint );
     for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
     pNew->u.vtab.omitMask = 0;
     for(i=0; i<nConstraint; i++, pIdxCons++){
@@ -4917,12 +4918,11 @@
           continue;
         }
         sCur.n = 0;
 #ifndef SQLITE_OMIT_VIRTUALTABLE
         if( IsVirtual(pItem->pTab) ){
-          rc = whereLoopAddVirtual(&sSubBuild);
-          for(i=0; i<sCur.n; i++) sCur.a[i].prereq |= mExtra;
+          rc = whereLoopAddVirtual(&sSubBuild, mExtra);
         }else
 #endif
         {
           rc = whereLoopAddBtree(&sSubBuild, mExtra);
         }
@@ -4988,11 +4988,11 @@
     if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
       mExtra = mPrior;
     }
     priorJoinType = pItem->jointype;
     if( IsVirtual(pItem->pTab) ){
-      rc = whereLoopAddVirtual(pBuilder);
+      rc = whereLoopAddVirtual(pBuilder, mExtra);
     }else{
       rc = whereLoopAddBtree(pBuilder, mExtra);
     }
     if( rc==SQLITE_OK ){
       rc = whereLoopAddOr(pBuilder, mExtra);