Implement IO#initialize_copy

3 files changed, 79 insertions, 1 deletions

diff --git a/mrbgems/mruby-io/README.md b/mrbgems/mruby-io/README.md
index 0f50e24ec..256fb8195 100644
--- a/mrbgems/mruby-io/README.md
+++ b/mrbgems/mruby-io/README.md
@@ -40,7 +40,7 @@ Add the line below to your `build_config.rb`:
 | IO#binmode?                |          |      |
 | IO#bytes                   |          | obsolete |
 | IO#chars                   |          | obsolete |
-| IO#clone, IO#dup           |          |      |
+| IO#clone, IO#dup           |    o     |      |
 | IO#close                   |    o     |      |
 | IO#close_on_exec=          |    o     |      |
 | IO#close_on_exec?          |    o     |      |
diff --git a/mrbgems/mruby-io/src/io.c b/mrbgems/mruby-io/src/io.c
index afd6dc7c3..643671d1e 100644
--- a/mrbgems/mruby-io/src/io.c
+++ b/mrbgems/mruby-io/src/io.c
@@ -530,6 +530,54 @@ mrb_io_s_popen(mrb_state *mrb, mrb_value klass)
 }
 #endif
 
+static int
+mrb_dup(mrb_state *mrb, int fd)
+{
+  int new_fd;
+
+  if (fd < 0)
+    return fd;
+
+  new_fd = dup(fd);
+  if (new_fd == -1)
+    mrb_sys_fail(mrb, 0);
+  return new_fd;
+}
+
+mrb_value
+mrb_io_initialize_copy(mrb_state *mrb, mrb_value copy)
+{
+  mrb_value orig;
+  mrb_value buf;
+  struct mrb_io *fptr_copy;
+  struct mrb_io *fptr_orig;
+
+  mrb_get_args(mrb, "o", &orig);
+  fptr_copy = (struct mrb_io *)DATA_PTR(copy);
+  if (fptr_copy != NULL) {
+    fptr_finalize(mrb, fptr_copy, FALSE);
+    mrb_free(mrb, fptr_copy);
+  }
+  fptr_copy = (struct mrb_io *)mrb_io_alloc(mrb);
+  fptr_orig = io_get_open_fptr(mrb, orig);
+
+  buf = mrb_iv_get(mrb, orig, mrb_intern_cstr(mrb, "@buf"));
+  mrb_iv_set(mrb, copy, mrb_intern_cstr(mrb, "@buf"), buf);
+
+  fptr_copy->fd = mrb_dup(mrb, fptr_orig->fd);
+  fptr_copy->fd2 = mrb_dup(mrb, fptr_orig->fd2);
+  fptr_copy->pid = fptr_orig->pid;
+  fptr_copy->readable = fptr_orig->readable;
+  fptr_copy->writable = fptr_orig->writable;
+  fptr_copy->sync = fptr_orig->sync;
+  fptr_copy->is_socket = fptr_orig->is_socket;
+
+  DATA_TYPE(copy) = &mrb_io_type;
+  DATA_PTR(copy) = fptr_copy;
+
+  return copy;
+}
+
 mrb_value
 mrb_io_initialize(mrb_state *mrb, mrb_value io)
 {
@@ -1238,6 +1286,7 @@ mrb_init_io(mrb_state *mrb)
 #endif
 
   mrb_define_method(mrb, io, "initialize", mrb_io_initialize, MRB_ARGS_ANY());    /* 15.2.20.5.21 (x)*/
+  mrb_define_method(mrb, io, "initialize_copy", mrb_io_initialize_copy, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, io, "_check_readable", mrb_io_check_readable, MRB_ARGS_NONE());
   mrb_define_method(mrb, io, "isatty",     mrb_io_isatty,     MRB_ARGS_NONE());
   mrb_define_method(mrb, io, "sync",       mrb_io_sync,       MRB_ARGS_NONE());
diff --git a/mrbgems/mruby-io/test/io.rb b/mrbgems/mruby-io/test/io.rb
index 9a6328ea4..96c3495d0 100644
--- a/mrbgems/mruby-io/test/io.rb
+++ b/mrbgems/mruby-io/test/io.rb
@@ -211,6 +211,35 @@ assert('IO#<<') do
   true
 end
 
+assert('IO#dup for readable') do
+  io = IO.new(IO.sysopen($mrbtest_io_rfname))
+  dup = io.dup
+  assert_true io != dup
+  assert_true io.fileno != dup.fileno
+  assert_equal 'm', dup.sysread(1)
+  assert_equal 'r', io.sysread(1)
+  assert_equal 'u', dup.sysread(1)
+  assert_equal 'b', io.sysread(1)
+  assert_equal 'y', dup.sysread(1)
+  dup.close
+  assert_false io.closed?
+  io.close
+  true
+end
+
+assert('IO#dup for writable') do
+  io = IO.open(IO.sysopen($mrbtest_io_wfname, 'w+'), 'w+')
+  dup = io.dup
+  io.syswrite "mruby"
+  assert_equal 5, dup.sysseek(0, IO::SEEK_CUR)
+  io.sysseek 0, IO::SEEK_SET
+  assert_equal 0, dup.sysseek(0, IO::SEEK_CUR)
+  assert_equal "mruby", dup.sysread(5)
+  dup.close
+  io.close
+  true
+end
+
 assert('IO.for_fd') do
   fd = IO.sysopen($mrbtest_io_rfname)
   io = IO.for_fd(fd)