Activate the ability to use expressions in indexes in a query. There are some

test failures, but mostly this seems to work.

FossilOrigin-Name: 42f93f582eccd8a778189aa6c113874f995ab751

4 files changed, 17 insertions, 2 deletions

diff --git a/src/insert.c b/src/insert.c
index 149096c04..73879303d 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -93,9 +93,12 @@ const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
       }else if( x==(-1) ){
         pIdx->zColAff[n] = SQLITE_AFF_INTEGER;
       }else{
+        char aff;
         assert( x==(-2) );
         assert( pIdx->aColExpr!=0 );
-        pIdx->zColAff[n] = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
+        aff = sqlite3ExprAffinity(pIdx->aColExpr->a[n].pExpr);
+        if( aff==0 ) aff = SQLITE_AFF_BLOB;
+        pIdx->zColAff[n] = aff;
       }
     }
     pIdx->zColAff[n] = 0;
diff --git a/src/where.c b/src/where.c
index 62a90cade..ad1eecd92 100644
--- a/src/where.c
+++ b/src/where.c
@@ -180,10 +180,13 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
   while( pScan->iEquiv<=pScan->nEquiv ){
     iCur = pScan->aiCur[pScan->iEquiv-1];
     iColumn = pScan->aiColumn[pScan->iEquiv-1];
+    assert( iColumn!=(-2) || pScan->pIdxExpr!=0 );
     while( (pWC = pScan->pWC)!=0 ){
       for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
         if( pTerm->leftCursor==iCur
          && pTerm->u.leftColumn==iColumn
+         && (iColumn!=(-2)
+               || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
          && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
         ){
           if( (pTerm->eOperator & WO_EQUIV)!=0
@@ -273,9 +276,11 @@ static WhereTerm *whereScanInit(
   /* memset(pScan, 0, sizeof(*pScan)); */
   pScan->pOrigWC = pWC;
   pScan->pWC = pWC;
+  pScan->pIdxExpr = 0;
   if( pIdx ){
     j = iColumn;
     iColumn = pIdx->aiColumn[j];
+    if( iColumn==(-2) ) pScan->pIdxExpr = pIdx->aColExpr->a[j].pExpr;
   }
   if( pIdx && iColumn>=0 ){
     pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
@@ -2224,7 +2229,7 @@ static int whereLoopAddBtreeIndex(
       int iCol = pProbe->aiColumn[saved_nEq];
       pNew->wsFlags |= WHERE_COLUMN_EQ;
       assert( saved_nEq==pNew->u.btree.nEq );
-      if( iCol==(-1) || (nInMul==0 && saved_nEq==pProbe->nKeyCol-1) ){
+      if( iCol==(-1) || (iCol>0 && nInMul==0 && saved_nEq==pProbe->nKeyCol-1) ){
         if( iCol>=0 && pProbe->uniqNotNull==0 ){
           pNew->wsFlags |= WHERE_UNQ_WANTED;
         }else{
diff --git a/src/whereInt.h b/src/whereInt.h
index 7138b85b2..65c118004 100644
--- a/src/whereInt.h
+++ b/src/whereInt.h
@@ -286,6 +286,7 @@ struct WhereScan {
   WhereClause *pOrigWC;      /* Original, innermost WhereClause */
   WhereClause *pWC;          /* WhereClause currently being scanned */
   char *zCollName;           /* Required collating sequence, if not NULL */
+  Expr *pIdxExpr;            /* Search for this index expression */
   char idxaff;               /* Must match this affinity, if zCollName!=NULL */
   unsigned char nEquiv;      /* Number of entries in aEquiv[] */
   unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
diff --git a/src/whereexpr.c b/src/whereexpr.c
index 88eb5b70a..631a7e0dc 100644
--- a/src/whereexpr.c
+++ b/src/whereexpr.c
@@ -872,6 +872,12 @@ static void exprAnalyze(
       pTerm->leftCursor = pLeft->iTable;
       pTerm->u.leftColumn = pLeft->iColumn;
       pTerm->eOperator = operatorMask(op) & opMask;
+    }else if( prereqLeft!=0 && (prereqLeft&(prereqLeft-1))==0 ){
+      int i;
+      for(i=0; (prereqLeft>>i)<1; i++){}
+      pTerm->leftCursor = pMaskSet->ix[i];
+      pTerm->u.leftColumn = -2;
+      pTerm->eOperator = operatorMask(op) & opMask;
     }
     if( op==TK_IS ) pTerm->wtFlags |= TERM_IS;
     if( pRight && pRight->op==TK_COLUMN ){