1 files changed, 74 insertions, 0 deletions

diff --git a/src/where.c b/src/where.c
index 2bd3e055d..39bbf7d64 100644
--- a/src/where.c
+++ b/src/where.c
@@ -5381,6 +5381,67 @@ static SQLITE_NOINLINE void whereCheckIfBloomFilterIsUseful(
 }
 
 /*
+** This is an sqlite3ParserAddCleanup() callback that is invoked to
+** free the Parse->pIdxExpr list when the Parse object is destroyed.
+*/
+static void whereIndexedExprCleanup(sqlite3 *db, void *pObject){
+  Parse *pParse = (Parse*)pObject;
+  while( pParse->pIdxExpr!=0 ){
+    IndexedExpr *p = pParse->pIdxExpr;
+    pParse->pIdxExpr = p->pIENext;
+    sqlite3ExprDelete(db, p->pExpr);
+    sqlite3DbFreeNN(db, p);
+  }
+}
+
+/*
+** The index pIdx is used by a query and contains one or more expressions.
+** In other words pIdx is an index on an expression.  iIdxCur is the cursor
+** number for the index and iDataCur is the cursor number for the corresponding
+** table.
+**
+** This routine adds IndexedExpr entries to the Parse->pIdxExpr field for
+** each of the expressions in the index so that the expression code generator
+** will know to replace occurrences of the indexed expression with
+** references to the corresponding column of the index.
+*/
+static SQLITE_NOINLINE void whereAddIndexedExpr(
+  Parse *pParse,     /* Add IndexedExpr entries to pParse->pIdxExpr */
+  Index *pIdx,       /* The index-on-expression that contains the expressions */
+  int iIdxCur,       /* Cursor number for pIdx */
+  SrcItem *pTabItem  /* The FROM clause entry for the table */
+){
+  int i;
+  IndexedExpr *p;
+  Table *pTab;
+  assert( pIdx->bHasExpr );
+  pTab = pIdx->pTable;
+  for(i=0; i<pIdx->nColumn; i++){
+    Expr *pExpr;
+    int j = pIdx->aiColumn[i];
+    if( j==XN_EXPR ){
+      pExpr = pIdx->aColExpr->a[i].pExpr;
+    }else if( j>=0 && (pTab->aCol[j].colFlags & COLFLAG_VIRTUAL)!=0 ){
+      pExpr = sqlite3ColumnExpr(pTab, &pTab->aCol[j]);
+    }else{
+      continue;
+    }
+    p = sqlite3DbMallocRaw(pParse->db,  sizeof(IndexedExpr));
+    if( p==0 ) break;
+    p->pIENext = pParse->pIdxExpr;
+    p->pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
+    p->iDataCur = pTabItem->iCursor;
+    p->iIdxCur = iIdxCur;
+    p->iIdxCol = i;
+    p->bMaybeNullRow = (pTabItem->fg.jointype & (JT_LEFT|JT_LTORJ))!=0;
+    pParse->pIdxExpr = p;
+    if( p->pIENext==0 ){
+      sqlite3ParserAddCleanup(pParse, whereIndexedExprCleanup, pParse);
+    }
+  }
+}
+
+/*
 ** Generate the beginning of the loop used for WHERE clause processing.
 ** The return value is a pointer to an opaque structure that contains
 ** information needed to terminate the loop.  Later, the calling routine
@@ -5925,6 +5986,9 @@ WhereInfo *sqlite3WhereBegin(
         op = OP_ReopenIdx;
       }else{
         iIndexCur = pParse->nTab++;
+        if( pIx->bHasExpr ){
+          whereAddIndexedExpr(pParse, pIx, iIndexCur, pTabItem);
+        }
       }
       pLevel->iIdxCur = iIndexCur;
       assert( pIx!=0 );
@@ -6321,6 +6385,16 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
       }else{
         last = pWInfo->iEndWhere;
       }
+      if( pIdx->bHasExpr ){
+        IndexedExpr *p = pParse->pIdxExpr;
+        while( p ){
+          if( p->iIdxCur==pLevel->iIdxCur ){
+            p->iDataCur = -1;
+            p->iIdxCur = -1;
+          }
+          p = p->pIENext;
+        }
+      }
       k = pLevel->addrBody + 1;
 #ifdef SQLITE_DEBUG
       if( db->flags & SQLITE_VdbeAddopTrace ){