Improved byte-code comments for the short-circuit optimization of

[0083d5169a46104a], to aid in debugging.

FossilOrigin-Name: 113f9d10e347eeaa893ff8b47a461009e0b12589374b93cf3e0bddd19c702dea

1 files changed, 7 insertions, 2 deletions

diff --git a/src/expr.c b/src/expr.c
index 9ed0a121e..c8dfd3af3 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2424,7 +2424,9 @@ static int exprComputeOperands(
   */
   if( exprEvalRhsFirst(pExpr) && sqlite3ExprCanBeNull(pExpr->pRight) ){
     r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
-    addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r2);  VdbeCoverage(v);
+    addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r2);
+    VdbeComment((v, "skip left operand"));
+    VdbeCoverage(v);
   }else{
     addrIsNull = 0;
   }
@@ -2439,7 +2441,9 @@ static int exprComputeOperands(
     if( ExprHasProperty(pExpr->pRight, EP_Subquery)
      && sqlite3ExprCanBeNull(pExpr->pLeft)
     ){
-      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r1);  VdbeCoverage(v);
+      addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, r1);
+      VdbeComment((v, "skip right operand"));
+      VdbeCoverage(v);
     }
     r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, pFree2);
   }
@@ -5112,6 +5116,7 @@ expr_code_doover:
         sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+2);
         sqlite3VdbeJumpHere(v, addrIsNull);
         sqlite3VdbeAddOp2(v, OP_Null, 0, target);
+        VdbeComment((v, "short-circut value"));
       }
       break;
     }