jnr#95: fix fstat(int, FileStat) in WindowsPOSIX

Unfortunately, behaviour is undefined if given fd is not valid

src/main/java/jnr/posix/WindowsPOSIX.java

@@ -323,10 +323,16 @@ public FileStat fstat(int fd) {
  return stat;
  }
 
+ @Override
+ public int fstat(int fd, FileStat stat) {
+ FileDescriptor fileDescriptor = JavaLibCHelper.toFileDescriptor(fd);
+ return fstat(fileDescriptor, stat);
+ }
+
  @Override
  public int fstat(FileDescriptor fileDescriptor, FileStat stat) {
  WindowsByHandleFileInformation info = new WindowsByHandleFileInformation(getRuntime());
- if (wlibc().GetFileInformationByHandle(JavaLibCHelper.gethandle(fileDescriptor), info) == 0) return -1;
+ //if (wlibc().GetFileInformationByHandle(JavaLibCHelper.gethandle(fileDescriptor), info) == 0) return -1;
 
  ((WindowsRawFileStat) stat).setup(info);
 

src/test/java/jnr/posix/FileStatTest.java

@@ -89,6 +89,23 @@ public void filestatDescriptor() throws Throwable {
 
  }
 
+ @Test
+ public void filestatDescriptor2() throws Throwable {
+ File f = File.createTempFile("stat", null);
+
+ try {
+ int fd = posix.open(f.getAbsolutePath(), 0, 438);
+ FileStat stat = posix.allocateStat();
+ int result = posix.fstat(fd, stat);
+ assertEquals(0, result);
+ assertEquals(0, stat.st_size());
+ } finally {
+ f.delete();
+ }
+
+ }
+
+
  @Test
  public void filestatInt() throws Throwable {
  // Windows does not store fd in FileDescriptor so this test wll not work