commit 8b65e5919d3f36d807d9f50e5ef649eacc77e0fe
author dan <dan@noemail.net> Wed Jul 17 14:34:17 2019 +0000
committer dan <dan@noemail.net> Wed Jul 17 14:34:17 2019 +0000
tree d5a68e0124b5fcbf92b2958476535c340abd0a37
parent 3db3d12cd11b60c47e52050eb3e83a67b7664d0f

When processing a BETWEEN or CASE expression, avoid transforming a node of the original expression into a TK_REGISTER node. Instead, take a copy and use it instead. Fix for [1be72aab9].

FossilOrigin-Name: 7ef7b23cbb1b9ace9f853238d9133320c153e6c3417e6823ab6394ee1fe56358

src/expr.c

diff --git a/src/expr.c b/src/expr.c
index 9ba81a8..56b3148 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1087,16 +1087,6 @@
 }
 
 /*
-** Copy the complete content of an Expr node, taking care not to read
-** past the end of the structure for a reduced-size version of the source
-** Expr.
-*/
-static void exprNodeCopy(Expr *pDest, Expr *pSrc){
-  memset(pDest, 0, sizeof(Expr));
-  memcpy(pDest, pSrc, exprStructSize(pSrc));
-}
-
-/*
 ** The dupedExpr*Size() routines each return the number of bytes required
 ** to store a copy of an expression or expression tree.  They differ in
 ** how much of the tree is measured.
@@ -4048,6 +4038,8 @@
       Expr opCompare;                   /* The X==Ei expression */
       Expr *pX;                         /* The X expression */
       Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */
+      Expr *pDel = 0;
+      sqlite3 *db = pParse->db;
 
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
       assert(pExpr->x.pList->nExpr > 0);
@@ -4056,13 +4048,17 @@
       nExpr = pEList->nExpr;
       endLabel = sqlite3VdbeMakeLabel(pParse);
       if( (pX = pExpr->pLeft)!=0 ){
-        exprNodeCopy(&tempX, pX);
+        pDel = sqlite3ExprDup(db, pX, 0);
+        if( db->mallocFailed ){
+          sqlite3ExprDelete(db, pDel);
+          break;
+        }
         testcase( pX->op==TK_COLUMN );
-        exprToRegister(&tempX, exprCodeVector(pParse, &tempX, &regFree1));
+        exprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
         testcase( regFree1==0 );
         memset(&opCompare, 0, sizeof(opCompare));
         opCompare.op = TK_EQ;
-        opCompare.pLeft = &tempX;
+        opCompare.pLeft = pDel;
         pTest = &opCompare;
         /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
         ** The value in regFree1 might get SCopy-ed into the file result.
@@ -4090,6 +4086,7 @@
       }else{
         sqlite3VdbeAddOp2(v, OP_Null, 0, target);
       }
+      sqlite3ExprDelete(db, pDel);
       sqlite3VdbeResolveLabel(v, endLabel);
       break;
     }
@@ -4371,40 +4368,44 @@
   void (*xJump)(Parse*,Expr*,int,int), /* Action to take */
   int jumpIfNull    /* Take the jump if the BETWEEN is NULL */
 ){
- Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
+  Expr exprAnd;     /* The AND operator in  x>=y AND x<=z  */
   Expr compLeft;    /* The  x>=y  term */
   Expr compRight;   /* The  x<=z  term */
-  Expr exprX;       /* The  x  subexpression */
   int regFree1 = 0; /* Temporary use register */
+  Expr *pDel = 0;
+  sqlite3 *db = pParse->db;
 
   memset(&compLeft, 0, sizeof(Expr));
   memset(&compRight, 0, sizeof(Expr));
   memset(&exprAnd, 0, sizeof(Expr));
 
   assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
-  exprNodeCopy(&exprX, pExpr->pLeft);
-  exprAnd.op = TK_AND;
-  exprAnd.pLeft = &compLeft;
-  exprAnd.pRight = &compRight;
-  compLeft.op = TK_GE;
-  compLeft.pLeft = &exprX;
-  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
-  compRight.op = TK_LE;
-  compRight.pLeft = &exprX;
-  compRight.pRight = pExpr->x.pList->a[1].pExpr;
-  exprToRegister(&exprX, exprCodeVector(pParse, &exprX, &regFree1));
-  if( xJump ){
-    xJump(pParse, &exprAnd, dest, jumpIfNull);
-  }else{
-    /* Mark the expression is being from the ON or USING clause of a join
-    ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
-    ** it into the Parse.pConstExpr list.  We should use a new bit for this,
-    ** for clarity, but we are out of bits in the Expr.flags field so we
-    ** have to reuse the EP_FromJoin bit.  Bummer. */
-    exprX.flags |= EP_FromJoin;
-    sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
+  pDel = sqlite3ExprDup(db, pExpr->pLeft, 0);
+  if( db->mallocFailed==0 ){
+    exprAnd.op = TK_AND;
+    exprAnd.pLeft = &compLeft;
+    exprAnd.pRight = &compRight;
+    compLeft.op = TK_GE;
+    compLeft.pLeft = pDel;
+    compLeft.pRight = pExpr->x.pList->a[0].pExpr;
+    compRight.op = TK_LE;
+    compRight.pLeft = pDel;
+    compRight.pRight = pExpr->x.pList->a[1].pExpr;
+    exprToRegister(pDel, exprCodeVector(pParse, pDel, &regFree1));
+    if( xJump ){
+      xJump(pParse, &exprAnd, dest, jumpIfNull);
+    }else{
+      /* Mark the expression is being from the ON or USING clause of a join
+      ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
+      ** it into the Parse.pConstExpr list.  We should use a new bit for this,
+      ** for clarity, but we are out of bits in the Expr.flags field so we
+      ** have to reuse the EP_FromJoin bit.  Bummer. */
+      pDel->flags |= EP_FromJoin;
+      sqlite3ExprCodeTarget(pParse, &exprAnd, dest);
+    }
+    sqlite3ReleaseTempReg(pParse, regFree1);
   }
-  sqlite3ReleaseTempReg(pParse, regFree1);
+  sqlite3ExprDelete(db, pDel);
 
   /* Ensure adequate test coverage */
   testcase( xJump==sqlite3ExprIfTrue  && jumpIfNull==0 && regFree1==0 );