Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -1338,11 +1338,12 @@
   char const *zOrigDb = 0;
   char const *zOrigTab = 0;
   char const *zOrigCol = 0;
 #endif
 
-  if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0;
+  assert( pExpr!=0 );
+  assert( pNC->pSrcList!=0 );
   switch( pExpr->op ){
     case TK_AGG_COLUMN:
     case TK_COLUMN: {
       /* The expression is a column. Locate the table the column is being
       ** extracted from in NameContext.pSrcList. This table may be real
@@ -1526,10 +1527,11 @@
   if( pParse->explain ){
     return;
   }
 #endif
 
+  assert( pTabList!=0 );
   if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return;
   pParse->colNamesSet = 1;
   fullNames = (db->flags & SQLITE_FullColNames)!=0;
   shortNames = (db->flags & SQLITE_ShortColNames)!=0;
   sqlite3VdbeSetNumCols(v, pEList->nExpr);
@@ -1538,11 +1540,11 @@
     p = pEList->a[i].pExpr;
     if( NEVER(p==0) ) continue;
     if( pEList->a[i].zName ){
       char *zName = pEList->a[i].zName;
       sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
-    }else if( (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN) && pTabList ){
+    }else if( p->op==TK_COLUMN || p->op==TK_AGG_COLUMN ){
       Table *pTab;
       char *zCol;
       int iCol = p->iColumn;
       for(j=0; ALWAYS(j<pTabList->nSrc); j++){
         if( pTabList->a[j].iCursor==p->iTable ) break;