Make sure limitedThreads <= partest.threads

Author: felixmulder

compiler/test/dotty/partest/DPConsoleRunner.scala

@@ -114,9 +114,16 @@ extends SuiteRunner(testSourcePath, fileManager, updateCheck, failed, javaCmdPat
     val seqResults =
       if (!limitResourceTests.isEmpty) {
         val savedThreads = sys.props("partest.threads")
-        sys.props("partest.threads") = limitedThreads
+        sys.props("partest.threads") = {
+          assert(
+            limitedThreads <= savedThreads,
+            """|Should not use more threads than the default, when the point
+               |is to limit the amount of resources""".stripMargin
+          )
+          limitedThreads
+        }
 
-        NestUI.echo(s"## we will run ${limitResourceTests.length} tests using ${PartestDefaults.numThreads} thread(s)")
+        NestUI.echo(s"## we will run ${limitResourceTests.length} tests using ${PartestDefaults.numThreads} thread(s) in parallel")
         val res = super.runTestsForFiles(limitResourceTests, kind)
 
         if (savedThreads != null)