Add support for "ORDER BY ... NULLS FIRST" and "ORDER BY ... NULLS LAST". Use this to fix ticket [f8a7060e].

FossilOrigin-Name: 94085fb3e756bc984237b74b6e29c68462ad860870c64dcb5124feaeec387660

1 files changed, 28 insertions, 8 deletions

diff --git a/src/expr.c b/src/expr.c
index fbb5ffafa..365f60665 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1409,8 +1409,9 @@ ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
     }
     pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
-    pItem->sortOrder = pOldItem->sortOrder;
+    pItem->sortFlags = pOldItem->sortFlags;
     pItem->done = 0;
+    pItem->bNulls = pOldItem->bNulls;
     pItem->bSpanIsTab = pOldItem->bSpanIsTab;
     pItem->bSorterRef = pOldItem->bSorterRef;
     pItem->u = pOldItem->u;
@@ -1666,15 +1667,34 @@ vector_append_error:
 /*
 ** Set the sort order for the last element on the given ExprList.
 */
-void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
+void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
+  struct ExprList_item *pItem;
   if( p==0 ) return;
-  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC>=0 && SQLITE_SO_DESC>0 );
   assert( p->nExpr>0 );
-  if( iSortOrder<0 ){
-    assert( p->a[p->nExpr-1].sortOrder==SQLITE_SO_ASC );
-    return;
+
+  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
+  assert( iSortOrder==SQLITE_SO_UNDEFINED 
+       || iSortOrder==SQLITE_SO_ASC 
+       || iSortOrder==SQLITE_SO_DESC 
+  );
+  assert( eNulls==SQLITE_SO_UNDEFINED 
+       || eNulls==SQLITE_SO_ASC 
+       || eNulls==SQLITE_SO_DESC 
+  );
+
+  pItem = &p->a[p->nExpr-1];
+  assert( pItem->bNulls==0 );
+  if( iSortOrder==SQLITE_SO_UNDEFINED ){
+    iSortOrder = SQLITE_SO_ASC;
+  }
+  pItem->sortFlags = (u8)iSortOrder;
+
+  if( eNulls!=SQLITE_SO_UNDEFINED ){
+    pItem->bNulls = 1;
+    if( iSortOrder!=eNulls ){
+      pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
+    }
   }
-  p->a[p->nExpr-1].sortOrder = (u8)iSortOrder;
 }
 
 /*
@@ -4935,7 +4955,7 @@ int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
   for(i=0; i<pA->nExpr; i++){
     Expr *pExprA = pA->a[i].pExpr;
     Expr *pExprB = pB->a[i].pExpr;
-    if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
+    if( pA->a[i].sortFlags!=pB->a[i].sortFlags ) return 1;
     if( sqlite3ExprCompare(0, pExprA, pExprB, iTab) ) return 1;
   }
   return 0;