1 files changed, 89 insertions, 26 deletions

diff --git a/src/where.c b/src/where.c
index c67a56964..85617bf05 100644
--- a/src/where.c
+++ b/src/where.c
@@ -625,11 +625,11 @@ static void exprAnalyzeAll(
 static int isLikeOrGlob(
   Parse *pParse,    /* Parsing and code generating context */
   Expr *pExpr,      /* Test this expression */
-  int *pnPattern,   /* Number of non-wildcard prefix characters */
+  Expr **ppPrefix,  /* Pointer to TK_STRING expression with pattern prefix */
   int *pisComplete, /* True if the only wildcard is % in the last character */
   int *pnoCase      /* True if uppercase is equivalent to lowercase */
 ){
-  const char *z;             /* String on RHS of LIKE operator */
+  const char *z = 0;         /* String on RHS of LIKE operator */
   Expr *pRight, *pLeft;      /* Right and left size of LIKE operator */
   ExprList *pList;           /* List of operands to the LIKE operator */
   int c;                     /* One character in z[] */
@@ -637,6 +637,8 @@ static int isLikeOrGlob(
   char wc[3];                /* Wildcard characters */
   CollSeq *pColl;            /* Collating sequence for LHS */
   sqlite3 *db = pParse->db;  /* Database connection */
+  sqlite3_value *pVal = 0;
+  int op;                    /* Opcode of pRight */
 
   if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){
     return 0;
@@ -645,10 +647,6 @@ static int isLikeOrGlob(
   if( *pnoCase ) return 0;
 #endif
   pList = pExpr->x.pList;
-  pRight = pList->a[0].pExpr;
-  if( pRight->op!=TK_STRING ){
-    return 0;
-  }
   pLeft = pList->a[1].pExpr;
   if( pLeft->op!=TK_COLUMN ){
     return 0;
@@ -661,19 +659,54 @@ static int isLikeOrGlob(
     return 0;
   }
   if( sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT ) return 0;
-  z = pRight->u.zToken;
-  if( ALWAYS(z) ){
+
+  pRight = pList->a[0].pExpr;
+  op = pRight->op;
+  if( op==TK_REGISTER ){
+    op = pRight->op2;
+  }
+  if( op==TK_VARIABLE ){
+    Vdbe *pReprepare = pParse->pReprepare;
+    pVal = sqlite3VdbeGetValue(pReprepare, pRight->iColumn, SQLITE_AFF_NONE);
+    if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
+      z = (char *)sqlite3_value_text(pVal);
+    }
+    sqlite3VdbeSetVarmask(pParse->pVdbe, pRight->iColumn, 0);
+    assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER );
+  }else if( op==TK_STRING ){
+    z = pRight->u.zToken;
+  }
+  if( z ){
     cnt = 0;
     while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){
       cnt++;
     }
     if( cnt!=0 && c!=0 && 255!=(u8)z[cnt-1] ){
+      Expr *pPrefix;
       *pisComplete = z[cnt]==wc[0] && z[cnt+1]==0;
-      *pnPattern = cnt;
-      return 1;
+      pPrefix = sqlite3Expr(db, TK_STRING, z);
+      if( pPrefix ) pPrefix->u.zToken[cnt] = 0;
+      *ppPrefix = pPrefix;
+      if( op==TK_VARIABLE ){
+        Vdbe *v = pParse->pVdbe;
+        sqlite3VdbeSetVarmask(v, pRight->iColumn, 1);
+        if( *pisComplete && pRight->u.zToken[1] ){
+          /* If the rhs of the LIKE expression is a variable, and the current
+          ** value of the variable means there is no need to invoke the LIKE
+          ** function, then no OP_Variable will be added to the program.
+          ** This causes problems for the sqlite3_bind_parameter_name()
+          ** API. To workaround them, add a dummy OP_Variable here.  */ 
+          sqlite3ExprCodeTarget(pParse, pRight, 1);
+          sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0);
+        }
+      }
+    }else{
+      z = 0;
     }
   }
-  return 0;
+
+  sqlite3ValueFree(pVal);
+  return (z!=0);
 }
 #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */
 
@@ -1055,12 +1088,12 @@ static void exprAnalyze(
   Bitmask prereqLeft;              /* Prerequesites of the pExpr->pLeft */
   Bitmask prereqAll;               /* Prerequesites of pExpr */
   Bitmask extraRight = 0;
-  int nPattern;
   int isComplete;
   int noCase;
   int op;                          /* Top-level operator.  pExpr->op */
   Parse *pParse = pWC->pParse;     /* Parsing context */
   sqlite3 *db = pParse->db;        /* Database connection */
+  Expr *pStr1;
 
   if( db->mallocFailed ){
     return;
@@ -1192,21 +1225,19 @@ static void exprAnalyze(
   ** The last character of the prefix "abc" is incremented to form the
   ** termination condition "abd".
   */
-  if( isLikeOrGlob(pParse, pExpr, &nPattern, &isComplete, &noCase)
-         && pWC->op==TK_AND ){
-    Expr *pLeft, *pRight;
-    Expr *pStr1, *pStr2;
+  if( pWC->op==TK_AND 
+   && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase)
+  ){
+    Expr *pLeft;
+    Expr *pStr2;
     Expr *pNewExpr1, *pNewExpr2;
     int idxNew1, idxNew2;
 
     pLeft = pExpr->x.pList->a[1].pExpr;
-    pRight = pExpr->x.pList->a[0].pExpr;
-    pStr1 = sqlite3Expr(db, TK_STRING, pRight->u.zToken);
-    if( pStr1 ) pStr1->u.zToken[nPattern] = 0;
     pStr2 = sqlite3ExprDup(db, pStr1, 0);
     if( !db->mallocFailed ){
       u8 c, *pC;       /* Last character before the first wildcard */
-      pC = (u8*)&pStr2->u.zToken[nPattern-1];
+      pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1];
       c = *pC;
       if( noCase ){
         /* The point is to increment the last character before the first
@@ -1985,6 +2016,39 @@ static int whereRangeRegion(
 #endif   /* #ifdef SQLITE_ENABLE_STAT2 */
 
 /*
+** If expression pExpr represents a literal value, set *pp to point to
+** an sqlite3_value structure containing the same value, with affinity
+** aff applied to it, before returning. It is the responsibility of the 
+** caller to eventually release this structure by passing it to 
+** sqlite3ValueFree().
+**
+** If the current parse is a recompile (sqlite3Reprepare()) and pExpr
+** is an SQL variable that currently has a non-NULL value bound to it,
+** create an sqlite3_value structure containing this value, again with
+** affinity aff applied to it, instead.
+**
+** If neither of the above apply, set *pp to NULL.
+**
+** If an error occurs, return an error code. Otherwise, SQLITE_OK.
+*/
+static int valueFromExpr(
+  Parse *pParse, 
+  Expr *pExpr, 
+  u8 aff, 
+  sqlite3_value **pp
+){
+  if( (pExpr->op==TK_VARIABLE)
+   || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE)
+  ){
+    int iVar = pExpr->iColumn;
+    sqlite3VdbeSetVarmask(pParse->pVdbe, iVar, 0);
+    *pp = sqlite3VdbeGetValue(pParse->pReprepare, iVar, aff);
+    return SQLITE_OK;
+  }
+  return sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, aff, pp);
+}
+
+/*
 ** This function is used to estimate the number of rows that will be visited
 ** by scanning an index for a range of values. The range may have an upper
 ** bound, a lower bound, or both. The WHERE clause terms that set the upper
@@ -2036,23 +2100,22 @@ static int whereRangeScanEst(
   int rc = SQLITE_OK;
 
 #ifdef SQLITE_ENABLE_STAT2
-  sqlite3 *db = pParse->db;
-  sqlite3_value *pLowerVal = 0;
-  sqlite3_value *pUpperVal = 0;
 
   if( nEq==0 && p->aSample ){
+    sqlite3_value *pLowerVal = 0;
+    sqlite3_value *pUpperVal = 0;
     int iEst;
     int iLower = 0;
     int iUpper = SQLITE_INDEX_SAMPLES;
-    u8 aff = p->pTable->aCol[0].affinity;
+    u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity;
 
     if( pLower ){
       Expr *pExpr = pLower->pExpr->pRight;
-      rc = sqlite3ValueFromExpr(db, pExpr, SQLITE_UTF8, aff, &pLowerVal);
+      rc = valueFromExpr(pParse, pExpr, aff, &pLowerVal);
     }
     if( rc==SQLITE_OK && pUpper ){
       Expr *pExpr = pUpper->pExpr->pRight;
-      rc = sqlite3ValueFromExpr(db, pExpr, SQLITE_UTF8, aff, &pUpperVal);
+      rc = valueFromExpr(pParse, pExpr, aff, &pUpperVal);
     }
 
     if( rc!=SQLITE_OK || (pLowerVal==0 && pUpperVal==0) ){