1 files changed, 15 insertions, 6 deletions
diff --git a/src/expr.c b/src/expr.c
index 201dedcc8..707dfe456 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1772,10 +1772,12 @@ static int selectNodeIsConstant(Walker *pWalker, Select *NotUsed){
 }
 static int exprIsConst(Expr *p, int initFlag, int iCur){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.eCode = initFlag;
   w.xExprCallback = exprNodeIsConstant;
   w.xSelectCallback = selectNodeIsConstant;
+#ifdef SQLITE_DEBUG
+  w.xSelectCallback2 = sqlite3SelectWalkAssert2;
+#endif
   w.u.iCur = iCur;
   sqlite3WalkExpr(&w, p);
   return w.eCode;
@@ -1863,9 +1865,9 @@ static int exprNodeIsConstantOrGroupBy(Walker *pWalker, Expr *pExpr){
 */
 int sqlite3ExprIsConstantOrGroupBy(Parse *pParse, Expr *p, ExprList *pGroupBy){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.eCode = 1;
   w.xExprCallback = exprNodeIsConstantOrGroupBy;
+  w.xSelectCallback = 0;
   w.u.pGroupBy = pGroupBy;
   w.pParse = pParse;
   sqlite3WalkExpr(&w, p);
@@ -1893,10 +1895,12 @@ int sqlite3ExprIsConstantOrFunction(Expr *p, u8 isInit){
 */
 int sqlite3ExprContainsSubquery(Expr *p){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.eCode = 1;
   w.xExprCallback = sqlite3ExprWalkNoop;
   w.xSelectCallback = selectNodeIsConstant;
+#ifdef SQLITE_DEBUG
+  w.xSelectCallback2 = sqlite3SelectWalkAssert2;
+#endif
   sqlite3WalkExpr(&w, p);
   return w.eCode==0;
 }
@@ -4901,8 +4905,8 @@ int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
   Walker w;
   struct SrcCount cnt;
   assert( pExpr->op==TK_AGG_FUNCTION );
-  memset(&w, 0, sizeof(w));
   w.xExprCallback = exprSrcCount;
+  w.xSelectCallback = 0;
   w.u.pSrcCount = &cnt;
   cnt.pSrc = pSrcList;
   cnt.nThis = 0;
@@ -5074,10 +5078,14 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
   return WRC_Continue;
 }
 static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
-  UNUSED_PARAMETER(pWalker);
   UNUSED_PARAMETER(pSelect);
+  pWalker->walkerDepth++;
   return WRC_Continue;
 }
+static void analyzeAggregatesInSelectEnd(Walker *pWalker, Select *pSelect){
+  UNUSED_PARAMETER(pSelect);
+  pWalker->walkerDepth--;
+}
 
 /*
 ** Analyze the pExpr expression looking for aggregate functions and
@@ -5090,9 +5098,10 @@ static int analyzeAggregatesInSelect(Walker *pWalker, Select *pSelect){
 */
 void sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
   Walker w;
-  memset(&w, 0, sizeof(w));
   w.xExprCallback = analyzeAggregate;
   w.xSelectCallback = analyzeAggregatesInSelect;
+  w.xSelectCallback2 = analyzeAggregatesInSelectEnd;
+  w.walkerDepth = 0;
   w.u.pNC = pNC;
   assert( pNC->pSrcList!=0 );
   sqlite3WalkExpr(&w, pExpr);