test/tools/javac/diags/MessageFile.java

*** 63,73 ****
              insertAfter(l);
              return l;
          }
  
          void insertAfter(Line l) {
-             assert prev == null && next == null;
              l.prev = this;
              l.next = next;
              if (next == null)
                  lastLine = l;
              else
--- 63,72 ----
*** 80,90 ****
              insertBefore(l);
              return l;
          }
  
          void insertBefore(Line l) {
-             assert prev == null && next == null;
              l.prev = prev;
              l.next = this;
              if (prev == null)
                  firstLine = l;
              else
--- 79,88 ----
*** 408,422 ****
      Line firstLine;
      Line lastLine;
      Map<String, Message> messages = new TreeMap<String, Message>();
  
      MessageFile(File file) throws IOException {
!         Reader in = new FileReader(file);
!         try {
              read(in);
-         } finally {
-             in.close();
          }
      }
  
      MessageFile(Reader in) throws IOException {
          read(in);
--- 406,417 ----
      Line firstLine;
      Line lastLine;
      Map<String, Message> messages = new TreeMap<String, Message>();
  
      MessageFile(File file) throws IOException {
!         try(Reader in = new FileReader(file)) {
              read(in);
          }
      }
  
      MessageFile(Reader in) throws IOException {
          read(in);
*** 440,454 ****
              }
          }
      }
  
      void write(File file) throws IOException {
!         Writer out = new FileWriter(file);
!         try {
              write(out);
-         } finally {
-             out.close();
          }
      }
  
      void write(Writer out) throws IOException {
          BufferedWriter bw = (out instanceof BufferedWriter)
--- 435,446 ----
              }
          }
      }
  
      void write(File file) throws IOException {
!         try(Writer out = new FileWriter(file)) {
              write(out);
          }
      }
  
      void write(Writer out) throws IOException {
          BufferedWriter bw = (out instanceof BufferedWriter)