Small optimization in the Expr tree walker.

FossilOrigin-Name: 264a5e1b75ee073bd019483e289c3d8d79abcf5a765435be23ac3c21b1db8246

1 files changed, 15 insertions, 11 deletions

diff --git a/src/walker.c b/src/walker.c
index 2e292295d..49f9fa189 100644
--- a/src/walker.c
+++ b/src/walker.c
@@ -40,18 +40,22 @@ static SQLITE_NOINLINE int walkExpr(Walker *pWalker, Expr *pExpr){
   int rc;
   testcase( ExprHasProperty(pExpr, EP_TokenOnly) );
   testcase( ExprHasProperty(pExpr, EP_Reduced) );
-  rc = pWalker->xExprCallback(pWalker, pExpr);
-  if( rc ) return rc & WRC_Abort;
-  if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){
-    if( pExpr->pLeft && walkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
-    assert( pExpr->x.pList==0 || pExpr->pRight==0 );
-    if( pExpr->pRight ){
-      if( walkExpr(pWalker, pExpr->pRight) ) return WRC_Abort;
-    }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-      if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
-    }else if( pExpr->x.pList ){
-      if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
+  while(1){
+    rc = pWalker->xExprCallback(pWalker, pExpr);
+    if( rc ) return rc & WRC_Abort;
+    if( !ExprHasProperty(pExpr,(EP_TokenOnly|EP_Leaf)) ){
+      if( pExpr->pLeft && walkExpr(pWalker, pExpr->pLeft) ) return WRC_Abort;
+       assert( pExpr->x.pList==0 || pExpr->pRight==0 );
+      if( pExpr->pRight ){
+        pExpr = pExpr->pRight;
+        continue;
+      }else if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        if( sqlite3WalkSelect(pWalker, pExpr->x.pSelect) ) return WRC_Abort;
+      }else if( pExpr->x.pList ){
+        if( sqlite3WalkExprList(pWalker, pExpr->x.pList) ) return WRC_Abort;
+      }
     }
+    break;
   }
   return WRC_Continue;
 }