commit 4ded26a53c4df312e9fd06facbbf70377e969983
author dan <dan@noemail.net> Thu Mar 28 16:15:05 2019 +0000
committer dan <dan@noemail.net> Thu Mar 28 16:15:05 2019 +0000
tree 7588d33692e04f5f0c7dcb72199b0cc9b98a2422
parent 6f1644c0f963c8d1d7388d6e52f60a6604aae2c1

Prevent aliases of window functions expressions from being used as arguments to aggregate or other window functions.

FossilOrigin-Name: 1e16d3e8fc60d39ca3899759ff15d355fdd7d3e23b325d8d2b0f954e11ce8dce

src/resolve.c

diff --git a/src/resolve.c b/src/resolve.c
index 2644e06..eb9e137 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -435,6 +435,10 @@
             sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
             return WRC_Abort;
           }
+          if( (pNC->ncFlags&NC_AllowWin)==0 && ExprHasProperty(pOrig, EP_Win) ){
+            sqlite3ErrorMsg(pParse, "misuse of aliased window function %s",zAs);
+            return WRC_Abort;
+          }
           if( sqlite3ExprVectorSize(pOrig)!=1 ){
             sqlite3ErrorMsg(pParse, "row value misused");
             return WRC_Abort;
@@ -725,6 +729,7 @@
       const char *zId;            /* The function name. */
       FuncDef *pDef;              /* Information about the function */
       u8 enc = ENC(pParse->db);   /* The database encoding */
+      int savedAllowFlags = (pNC->ncFlags & (NC_AllowAgg | NC_AllowWin));
 
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
       zId = pExpr->u.zToken;
@@ -846,8 +851,11 @@
           pNC->nErr++;
         }
         if( is_agg ){
+          /* Window functions may not be arguments of aggregate functions.
+          ** Or arguments of other window functions. But aggregate functions
+          ** may be arguments for window functions.  */
 #ifndef SQLITE_OMIT_WINDOWFUNC
-          pNC->ncFlags &= ~(pExpr->y.pWin ? NC_AllowWin : NC_AllowAgg);
+          pNC->ncFlags &= ~(NC_AllowWin | (!pExpr->y.pWin ? NC_AllowAgg : 0));
 #else
           pNC->ncFlags &= ~NC_AllowAgg;
 #endif
@@ -868,7 +876,7 @@
             pExpr->y.pWin->pNextWin = pSel->pWin;
             pSel->pWin = pExpr->y.pWin;
           }
-          pNC->ncFlags |= NC_AllowWin;
+          pNC->ncFlags |= NC_HasWin;
         }else
 #endif /* SQLITE_OMIT_WINDOWFUNC */
         {
@@ -886,8 +894,8 @@
             pNC2->ncFlags |= NC_HasAgg | (pDef->funcFlags & SQLITE_FUNC_MINMAX);
 
           }
-          pNC->ncFlags |= NC_AllowAgg;
         }
+        pNC->ncFlags |= savedAllowFlags;
       }
       /* FIX ME:  Compute pExpr->affinity based on the expected return
       ** type of the function 
@@ -1648,8 +1656,8 @@
   Walker w;
 
   if( pExpr==0 ) return SQLITE_OK;
-  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg);
-  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg);
+  savedHasAgg = pNC->ncFlags & (NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
+  pNC->ncFlags &= ~(NC_HasAgg|NC_MinMaxAgg|NC_HasWin);
   w.pParse = pNC->pParse;
   w.xExprCallback = resolveExprStep;
   w.xSelectCallback = resolveSelectStep;
@@ -1668,6 +1676,9 @@
   if( pNC->ncFlags & NC_HasAgg ){
     ExprSetProperty(pExpr, EP_Agg);
   }
+  if( pNC->ncFlags & NC_HasWin ){
+    ExprSetProperty(pExpr, EP_Win);
+  }
   pNC->ncFlags |= savedHasAgg;
   return pNC->nErr>0 || w.pParse->nErr>0;
 }