workaround #23435; real fix pending #23279 (#23436)

workaround #23435

related to https://github.com/nim-lang/Nim/issues/22852

see also #23279

lib/system/indices.nim

@@ -80,6 +80,8 @@ proc `[]`*[T, U: Ordinal](s: string, x: HSlice[T, U]): string {.inline, systemRa
   ##   var s = "abcdef"
   ##   assert s[1..3] == "bcd"
   ##   ```
+  # Workaround bug #22852
+  result = ""
   let a = s ^^ x.a
   let L = (s ^^ x.b) - a + 1
   result = newString(L)

tests/errmsgs/t23435.nim

@@ -0,0 +1,12 @@
+discard """
+  outputsub: "Error: unhandled exception: value out of range: -15 notin 0 .. 9223372036854775807 [RangeDefect]"
+  exitcode: "1"
+"""
+
+# bug #23435
+proc foo() =
+  for _ in @[1, 3, 5]:
+    discard "abcde"[25..<10]
+    break
+
+foo()