remove seq[T] setLen undefined behavior (#21582)

remove seq[T] setLen UB
nim-lang · Mar 29, 2023 · 51ced0d · 51ced0d
1 parent c06623b
commit 51ced0d
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
@@ -1947,7 +1947,7 @@ proc genSetLengthSeq(p: BProc, e: PNode, d: var TLoc) =
 
   initLoc(call, locCall, e, OnHeap)
   if not p.module.compileToCpp:
-    const setLenPattern = "($3) #setLengthSeqV2(&($1)->Sup, $4, $2)"
+    const setLenPattern = "($3) #setLengthSeqV2(($1)?&($1)->Sup:NIM_NIL, $4, $2)"
     call.r = ropecg(p.module, setLenPattern, [
       rdLoc(a), rdLoc(b), getTypeDesc(p.module, t),
       genTypeInfoV1(p.module, t.skipTypes(abstractInst), e.info)])