When flipping ("commuting") a comparison operator, set the new EP_Commuted

bit rather than adding extra EP_Collate bits, to single later processing that
the order of precedence for COLLATE operators is inverted.
Fix for ticket [b47e3627ecaadbde]

FossilOrigin-Name: 90f7c477354d67d22d5eb0da22dac579f384ab44743fdc19887220e32203ebc2

1 files changed, 31 insertions, 7 deletions

diff --git a/src/expr.c b/src/expr.c
index 0e827482b..7e80796f4 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -339,6 +339,22 @@ CollSeq *sqlite3BinaryCompareCollSeq(
   return pColl;
 }
 
+/* Expresssion p is a comparison operator.  Return a collation sequence
+** appropriate for the comparison operator.
+**
+** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
+** However, if the OP_Commuted flag is set, then the order of the operands
+** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
+** correct collating sequence is found.
+*/
+CollSeq *sqlite3ExprCompareCollSeq(Parse *pParse, Expr *p){
+  if( ExprHasProperty(p, EP_Commuted) ){
+    return sqlite3BinaryCompareCollSeq(pParse, p->pRight, p->pLeft);
+  }else{
+    return sqlite3BinaryCompareCollSeq(pParse, p->pLeft, p->pRight);
+  }
+}
+
 /*
 ** Generate code for a comparison operator.
 */
@@ -349,13 +365,18 @@ static int codeCompare(
   int opcode,       /* The comparison opcode */
   int in1, int in2, /* Register holding operands */
   int dest,         /* Jump here if true.  */
-  int jumpIfNull    /* If true, jump if either operand is NULL */
+  int jumpIfNull,   /* If true, jump if either operand is NULL */
+  int isCommuted    /* The comparison has been commuted */
 ){
   int p5;
   int addr;
   CollSeq *p4;
 
-  p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
+  if( isCommuted ){
+    p4 = sqlite3BinaryCompareCollSeq(pParse, pRight, pLeft);
+  }else{
+    p4 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
+  }
   p5 = binaryCompareP5(pLeft, pRight, jumpIfNull);
   addr = sqlite3VdbeAddOp4(pParse->pVdbe, opcode, in2, dest, in1,
                            (void*)p4, P4_COLLSEQ);
@@ -566,6 +587,7 @@ static void codeVectorCompare(
   int regRight = 0;
   u8 opx = op;
   int addrDone = sqlite3VdbeMakeLabel(pParse);
+  int isCommuted = ExprHasProperty(pExpr,EP_Commuted);
 
   if( nLeft!=sqlite3ExprVectorSize(pRight) ){
     sqlite3ErrorMsg(pParse, "row value misused");
@@ -595,7 +617,7 @@ static void codeVectorCompare(
     assert( i>=0 && i<nLeft );
     r1 = exprVectorRegister(pParse, pLeft, i, regLeft, &pL, &regFree1);
     r2 = exprVectorRegister(pParse, pRight, i, regRight, &pR, &regFree2);
-    codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5);
+    codeCompare(pParse, pL, pR, opx, r1, r2, dest, p5, isCommuted);
     testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
     testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
     testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
@@ -3665,7 +3687,8 @@ expr_code_doover:
         r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
         r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
         codeCompare(pParse, pLeft, pExpr->pRight, op,
-            r1, r2, inReg, SQLITE_STOREP2 | p5);
+            r1, r2, inReg, SQLITE_STOREP2 | p5,
+            ExprHasProperty(pExpr,EP_Commuted));
         assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
         assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
         assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
@@ -4585,7 +4608,7 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, jumpIfNull);
+                  r1, r2, dest, jumpIfNull, ExprHasProperty(pExpr,EP_Commuted));
       assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
@@ -4760,7 +4783,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
       r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
       r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
-                  r1, r2, dest, jumpIfNull);
+                  r1, r2, dest, jumpIfNull,ExprHasProperty(pExpr,EP_Commuted));
       assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
       assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);
       assert(TK_GT==OP_Gt); testcase(op==OP_Gt); VdbeCoverageIf(v,op==OP_Gt);
@@ -4946,7 +4969,8 @@ int sqlite3ExprCompare(Parse *pParse, Expr *pA, Expr *pB, int iTab){
       return 2;
     }
   }
-  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
+  if( (pA->flags & (EP_Distinct|EP_Commuted))
+     != (pB->flags & (EP_Distinct|EP_Commuted)) ) return 2;
   if( (combinedFlags & EP_TokenOnly)==0 ){
     if( combinedFlags & EP_xIsSelect ) return 2;
     if( (combinedFlags & EP_FixedCol)==0