Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -4086,11 +4086,11 @@
         Table *pTab = pCol->pTab;
         sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                               pCol->iSorterColumn, target);
         if( pCol->iColumn<0 ){
           VdbeComment((v,"%s.rowid",pTab->zName));
-        }else{
+        }else if( ALWAYS(pTab!=0) ){
           VdbeComment((v,"%s.%s", 
               pTab->zName, pTab->aCol[pCol->iColumn].zCnName));
           if( pTab->aCol[pCol->iColumn].affinity==SQLITE_AFF_REAL ){
             sqlite3VdbeAddOp1(v, OP_RealAffinity, target);
           }
@@ -6225,12 +6225,14 @@
             ** is not an entry there already.
             */
             int k;
             pCol = pAggInfo->aCol;
             for(k=0; k<pAggInfo->nColumn; k++, pCol++){
-              if( pCol->iTable==pExpr->iTable &&
-                  pCol->iColumn==pExpr->iColumn ){
+              if( pCol->iTable==pExpr->iTable
+               && pCol->iColumn==pExpr->iColumn
+               && pExpr->op!=TK_IF_NULL_ROW
+              ){
                 break;
               }
             }
             if( (k>=pAggInfo->nColumn)
              && (k = addAggInfoColumn(pParse->db, pAggInfo))>=0 
@@ -6241,19 +6243,21 @@
               pCol->iTable = pExpr->iTable;
               pCol->iColumn = pExpr->iColumn;
               pCol->iMem = ++pParse->nMem;
               pCol->iSorterColumn = -1;
               pCol->pCExpr = pExpr;
-              if( pAggInfo->pGroupBy ){
+              if( pAggInfo->pGroupBy && pExpr->op!=TK_IF_NULL_ROW ){
                 int j, n;
                 ExprList *pGB = pAggInfo->pGroupBy;
                 struct ExprList_item *pTerm = pGB->a;
                 n = pGB->nExpr;
                 for(j=0; j<n; j++, pTerm++){
                   Expr *pE = pTerm->pExpr;
-                  if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
-                      pE->iColumn==pExpr->iColumn ){
+                  if( pE->op==TK_COLUMN
+                   && pE->iTable==pExpr->iTable
+                   && pE->iColumn==pExpr->iColumn
+                  ){
                     pCol->iSorterColumn = j;
                     break;
                   }
                 }
               }

Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -3796,10 +3796,11 @@
         if( pSubst->isOuterJoin && pCopy->op!=TK_COLUMN ){
           memset(&ifNullRow, 0, sizeof(ifNullRow));
           ifNullRow.op = TK_IF_NULL_ROW;
           ifNullRow.pLeft = pCopy;
           ifNullRow.iTable = pSubst->iNewTable;
+          ifNullRow.iColumn = -99;
           ifNullRow.flags = EP_IfNullRow;
           pCopy = &ifNullRow;
         }
         testcase( ExprHasProperty(pCopy, EP_Subquery) );
         pNew = sqlite3ExprDup(db, pCopy, 0);
@@ -7416,12 +7417,17 @@
       if( minMaxFlag ){
         sqlite3DebugPrintf("MIN/MAX Optimization (0x%02x) adds:\n", minMaxFlag);
         sqlite3TreeViewExprList(0, pMinMaxOrderBy, 0, "ORDERBY");
       }
       for(ii=0; ii<pAggInfo->nColumn; ii++){
-        sqlite3DebugPrintf("agg-column[%d] iMem=%d\n",
-            ii, pAggInfo->aCol[ii].iMem);
+        struct AggInfo_col *pCol = &pAggInfo->aCol[ii];
+        sqlite3DebugPrintf(
+           "agg-column[%d] pTab=%s iTable=%d iColumn=%d iMem=%d"
+           " iSorterColumn=%d\n",
+           ii, pCol->pTab ? pCol->pTab->zName : "NULL", 
+           pCol->iTable, pCol->iColumn, pCol->iMem,
+           pCol->iSorterColumn);
         sqlite3TreeViewExpr(0, pAggInfo->aCol[ii].pCExpr, 0);
       }
       for(ii=0; ii<pAggInfo->nFunc; ii++){
         sqlite3DebugPrintf("agg-func[%d]: iMem=%d\n",
             ii, pAggInfo->aFunc[ii].iMem);

Index: test/select3.test
==================================================================
--- test/select3.test
+++ test/select3.test
@@ -372,7 +372,66 @@
         SELECT 'constant' AS val FROM t2 WHERE x=1234
     )
   } {abc constant}
 }
 
+reset_db
+do_execsql_test 12.0 {
+  CREATE TABLE t1(a);
+  CREATE TABLE t2(x);
+}
+do_execsql_test 12.1 {
+  SELECT count(x), m FROM t1 LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+}
+do_execsql_test 12.2 {
+  INSERT INTO t1 VALUES(1), (1), (2), (3);
+  SELECT count(x), m FROM t1 LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+} {
+  0 {}
+  0 {}
+  0 {}
+}
+do_execsql_test 12.3 {
+  INSERT INTO t2 VALUES(45);
+  SELECT count(x), m FROM t1 LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+} {
+  2 59
+  1 59
+  1 59
+}
+do_execsql_test 12.4 {
+  INSERT INTO t2 VALUES(210);
+  SELECT count(x), m FROM t1 LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+} {
+  4 59
+  2 59
+  2 59
+}
+do_execsql_test 12.5 {
+  INSERT INTO t2 VALUES(NULL);
+  SELECT count(x), m FROM t1 LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+} {
+  4 59
+  2 59
+  2 59
+}
+do_execsql_test 12.6 {
+  DELETE FROM t2;
+  DELETE FROM t1;
+  INSERT INTO t1 VALUES('value');
+  INSERT INTO t2 VALUES('hello');
+} {}
+do_execsql_test 12.7 {
+  SELECT group_concat(x), m FROM t1 
+    LEFT JOIN (SELECT x, 59 AS m FROM t2) GROUP BY a;
+} {
+  hello 59
+}
+do_execsql_test 12.8 {
+  SELECT group_concat(x), m, n FROM t1 
+    LEFT JOIN (SELECT x, 59 AS m, 60 AS n FROM t2) GROUP BY a;
+} {
+  hello 59 60
+}
 
 finish_test
+