Failing string ordering on linux test

This testcase illustrates a problem on linux where - at the time
of writing - the strings "a" and "a\0" satisfied
"a" <= "a\0"
"a" >= "a\0"
"a" != "a\0"

Author: rtreffer

test/1_stdlib/StringOrderRelation.swift

@@ -0,0 +1,28 @@
+// RUN: %target-run-simple-swift
+// REQUIRES: executable_test
+
+import StdlibUnittest
+
+// Also import modules which are used by StdlibUnittest internally. This
+// workaround is needed to link all required libraries in case we compile
+// StdlibUnittest with -sil-serialize-all.
+import SwiftPrivate
+#if _runtime(_ObjC)
+import ObjectiveC
+#endif
+
+var StringOrderRelationTestSuite = TestSuite("StringOrderRelation")
+
+StringOrderRelationTestSuite.test("StringOrderRelation/ASCII/NullByte") {
+  let baseString = "a"
+  let nullbyteString = "a\0"
+  expectTrue(baseString < nullbyteString)
+  expectTrue(baseString <= nullbyteString)
+  expectFalse(baseString > nullbyteString)
+  expectFalse(baseString >= nullbyteString)
+  expectFalse(baseString == nullbyteString)
+  expectTrue(baseString != nullbyteString)
+}
+
+runAllTests()
+