Fix legacy windows platform for multibyte unicode

- Add handling to create correctly sized buffer even with multibyte
characters as len() in python does not line up with what
create_unicode_buffer() needs for length.
- Add test for single and multiple files

send2trash/plat_win_legacy.py

@@ -77,8 +77,6 @@ def send2trash(paths):
     paths = [op.abspath(path) if not op.isabs(path) else path for path in paths]
     # get short path to handle path length issues
     paths = [get_short_path_name(path) for path in paths]
-    # convert to a single string of null terminated paths
-    paths = "\0".join(paths)
     fileop = SHFILEOPSTRUCTW()
     fileop.hwnd = 0
     fileop.wFunc = FO_DELETE
@@ -93,7 +91,15 @@ def send2trash(paths):
     # NOTE: based on how python allocates memory for these types they should
     # always be zero, if this is ever not true we can go back to explicitly
     # setting the last two characters to null using buffer[index] = '\0'.
-    buffer = create_unicode_buffer(paths, len(paths) + 2)
+    # Additional note on another issue here, unicode_buffer expects length in
+    # bytes essentially, so having multi-byte characters causes issues if just
+    # passing pythons string length.  Instead of dealing with this difference we
+    # just create a buffer then a new one with an extra null.  Since the non-length
+    # specified version apparently stops after the first null, join with a space first.
+    buffer = create_unicode_buffer(" ".join(paths))
+    # convert to a single string of null terminated paths
+    path_string = "\0".join(paths)
+    buffer = create_unicode_buffer(path_string, len(buffer) + 1)
     fileop.pFrom = LPCWSTR(addressof(buffer))
     fileop.pTo = None
     fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT

tests/test_plat_win.py

@@ -66,6 +66,17 @@ def _file_not_found(dir, fcn):
     pytest.raises(OSError, fcn, file)
 
 
+def _multi_byte_unicode(dir, fcn):
+    file = op.join(dir, "😇.txt")
+    _create_tree(file)
+    fcn(file)
+    assert op.exists(file) is False
+    files = [op.join(dir, "😇{}.txt".format(index)) for index in range(10)]
+    [_create_tree(file) for file in files]
+    fcn(files)
+    assert any([op.exists(file) for file in files]) is False
+
+
 def test_trash_folder(testdir):
     _trash_folder(testdir, s2t)
 
@@ -98,6 +109,10 @@ def test_file_not_found_modern(testdir):
     _file_not_found(testdir, s2t_modern)
 
 
+def test_multi_byte_unicode_modern(testdir):
+    _multi_byte_unicode(testdir, s2t_modern)
+
+
 def test_trash_folder_legacy(testdir):
     _trash_folder(testdir, s2t_legacy)
 
@@ -114,6 +129,10 @@ def test_file_not_found_legacy(testdir):
     _file_not_found(testdir, s2t_legacy)
 
 
+def test_multi_byte_unicode_legacy(testdir):
+    _multi_byte_unicode(testdir, s2t_legacy)
+
+
 # Long path tests
 @pytest.fixture
 def longdir(tmp_path):