fix: duplicated file may has different line endings (#77)

* fix: duplicated file may has different line endings

Python's stream writing uses OS's line ending.
So if you duplicate a Unix line ending file on Windows by writing file
content, the duplicate file will use \r\n as its line ending.

Why we don't use copy file API at the first place?

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

* fix: disallow duplicate file with dst = src

It just can't be done. Even worse, if the user select "overwrite",
the source file gets deleted first, and no destination file will be
created because no source file can be opened anymore.

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

* style: make black happy

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

Author: jfcherng

commands/create_from_selection.py

@@ -43,7 +43,7 @@ def want_event(self):
 
     def get_path(self, event, for_context_menu=False):
         """
-            @return (base_path: str, relative_path: str)
+        @return (base_path: str, relative_path: str)
         """
         file_name = None
         region = self.view.sel()[0]

commands/duplicate.py

@@ -42,6 +42,10 @@ def run(self, paths=None):
     def duplicate(self, dst, input_path):
         user_friendly_path = user_friendly(dst)
 
+        if os.path.abspath(self.origin) == os.path.abspath(dst):
+            sublime.error_message("Destination is the same with the source.")
+            return
+
         if os.path.isdir(self.origin):
             if not os.path.exists(dst):
                 shutil.copytree(self.origin, dst)
@@ -53,9 +57,7 @@ def duplicate(self, dst, input_path):
                 )
         else:
             if not os.path.exists(dst):
-                with open(dst, "w") as fp:
-                    with open(self.origin, "r") as fpread:
-                        fp.write(fpread.read())
+                shutil.copy2(self.origin, dst)
                 self.window.open_file(dst)
             else:
 
@@ -68,9 +70,7 @@ def overwrite():
                             "Unable to send to the trash the item {0}".format(e)
                         )
 
-                    with open(dst, "w") as fp:
-                        with open(self.origin, "r") as fpread:
-                            fp.write(fpread.read())
+                    shutil.copy2(self.origin, dst)
                     self.window.open_file(dst)
 
                 def open_file():