fixes #20954; bounchecks for len(toOpenArray()) [backport] (#20956)

* bounchecks for len(toOpenArray()) * add a testcase
2022-12-06 05:27:18 +08:00 · 2022-12-06 05:27:18 +08:00 · b83bd282dc
commit b83bd282dc
parent a8090f7d65
2 changed files with 20 additions and 0 deletions
--- a/tests/arc/topenarray.nim
+++ b/tests/arc/topenarray.nim
@ -22,3 +22,19 @@ block: # bug 18627
    for i in params.toOpenArray(0, params.len - 1):
      echo i
  uciLoop2()
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+block: # bug #20954
+  block:
+    doAssertRaises(IndexDefect):
+      var v: array[10, int]
+
+      echo len(toOpenArray(v, 20, 30))
+
+  block:
+    doAssertRaises(IndexDefect):
+      var v: seq[int]
+
+      echo len(toOpenArray(v, 20, 30))