Fix the OP_Copy-coalesce optimization so that if the previous row happens
to end with OP_Copy but is not a candidate for the optimization due to jumps,
then the optimization is correctly bypassed.
FossilOrigin-Name: b36126c1889e323c9a8f04b4f4884576993c845e7d393e5e73aaa6ab5158c1f9
diff --git a/src/expr.c b/src/expr.c
index cc795c0..0c4a611 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3620,6 +3620,9 @@
VdbeCoverage(v);
sqlite3ExprCode(pParse, pFarg->a[i].pExpr, target);
}
+ if( sqlite3VdbeGetOp(v, -1)->opcode==OP_Copy ){
+ sqlite3VdbeChangeP5(v, 1); /* Tag trailing OP_Copy as not mergable */
+ }
sqlite3VdbeResolveLabel(v, endCoalesce);
break;
}
@@ -4607,6 +4610,7 @@
&& (pOp=sqlite3VdbeGetOp(v, -1))->opcode==OP_Copy
&& pOp->p1+pOp->p3+1==inReg
&& pOp->p2+pOp->p3+1==target+i
+ && pOp->p5==0 /* The do-not-merge flag must be clear */
){
pOp->p3++;
}else{