Fix the issue #404

py7zr/archiveinfo.py

@@ -751,6 +751,10 @@ def _read(self, fp: BinaryIO):
                 self._read_start_pos(buffer)
             else:
                 raise Bad7zFile("invalid type %r" % prop)  # pragma: no-cover
+        # re-calculate self.emptyfiles for next append
+        if numfiles > 0 and len(self.emptyfiles) == 0:
+            for f in self.files:
+                self.emptyfiles.append(f.get("emptystream"))
 
     def _read_name(self, buffer: BinaryIO) -> None:
         for f in self.files:

py7zr/py7zr.py

@@ -1464,6 +1464,9 @@ def write(self, fp: BinaryIO, f, assym, folder):
     def writestr(self, fp: BinaryIO, f, folder):
         compressor = folder.get_compressor()
         insize, foutsize, crc = compressor.compress(f.data(), fp)
+        if insize == 0:
+            fp.seek(-1 * foutsize, 1)  # rewind
+            return 0, None
         return self._after_write(insize, foutsize, crc)
 
     def flush_archive(self, fp, folder):

tests/test_archive.py

@@ -9,6 +9,7 @@
 import shutil
 import stat
 import sys
+import zipfile
 from datetime import datetime
 
 import pytest
@@ -1123,3 +1124,68 @@ def test_compress_append_archive_w_zerofile(tmp_path):
     #
     with py7zr.SevenZipFile(target, "r") as arc:
         arc.extractall(path=tmp_path / "tgt")
+
+
+@pytest.mark.basic
+def test_compress_file_append_dir(tmp_path):
+    srcpath = tmp_path.joinpath("src")
+    srcpath.mkdir()
+    with zipfile.ZipFile(pathlib.Path(testdata_path).joinpath("github_404.zip")) as zipsrc:
+        zipsrc.extractall(path=srcpath)
+    target = tmp_path.joinpath("target.7z")
+    archive = py7zr.SevenZipFile(target, "w")
+    archive.write(srcpath.joinpath("a.xlsx"), arcname="a.xlsx")
+    archive.close()
+    #
+    archive = py7zr.SevenZipFile(target, "a")
+    archive.set_encoded_header_mode(False)
+    archive.writeall(srcpath.joinpath("22"), arcname="22")
+    assert len(archive.header.main_streams.unpackinfo.folders) == 2
+    assert archive.header.main_streams.unpackinfo.numfolders == 2
+    #
+    assert len(archive.header.files_info.files) == 8
+    assert archive.header.files_info.files[0].get("filename") == "a.xlsx"
+    assert archive.header.files_info.files[0].get("digest") == 0x83ef96ba
+    assert archive.header.files_info.files[1].get("filename") == "22"
+    assert archive.header.files_info.files[2].get("filename") == "22/a.xlsx"
+    assert archive.header.files_info.files[2].get("digest") == 0x6d452c78
+    assert archive.header.files_info.files[3].get("filename") == "22/extra.csv"
+    assert archive.header.files_info.files[3].get("digest") == 0xfb91a7eb
+    assert archive.header.files_info.files[4].get("filename") == "22/purchase_notice.csv"
+    assert archive.header.files_info.files[4].get("digest") == 0x18991f62
+    assert archive.header.files_info.files[5].get("filename") == "22/res11.csv"
+    assert archive.header.files_info.files[5].get("digest") == 0x4719daea
+    assert archive.header.files_info.files[6].get("filename") == "22/res122.csv"
+    assert archive.header.files_info.files[6].get("digest") == 0x72f7c99f
+    assert archive.header.files_info.files[7].get("filename") == "22/res_end.csv"
+    assert archive.header.files_info.files[7].get("digest") == 0xaa8b30d0
+    #
+    assert len(archive.header.files_info.emptyfiles) == 8
+    assert not archive.header.files_info.emptyfiles[0]
+    assert archive.header.files_info.emptyfiles[1]
+    assert not archive.header.files_info.emptyfiles[2]
+    #
+    assert len(archive.files.files_list) == 8
+    assert archive.files.files_list[0].get("filename") == "a.xlsx"
+    assert archive.files.files_list[0].get("uncompressed") == 10059
+    assert archive.files.files_list[1].get("filename") == "22"
+    assert archive.files.files_list[1].get("emptystream") is True
+    assert archive.files.files_list[2].get("filename") == "22/a.xlsx"
+    assert archive.files.files_list[2].get("uncompressed") == 45298
+    assert archive.files.files_list[3].get("filename") == "22/extra.csv"
+    assert archive.files.files_list[3].get("uncompressed") == 45298
+    assert archive.files.files_list[4].get("filename") == "22/purchase_notice.csv"
+    assert archive.files.files_list[4].get("uncompressed") == 45298
+    assert archive.files.files_list[5].get("filename") == "22/res11.csv"
+    assert archive.files.files_list[5].get("uncompressed") == 10838
+    assert archive.files.files_list[6].get("filename") == "22/res122.csv"
+    assert archive.files.files_list[6].get("uncompressed") == 236458
+    assert archive.files.files_list[7].get("filename") == "22/res_end.csv"
+    assert archive.files.files_list[7].get("uncompressed") == 216681
+    archive.close()
+    #
+    p7zip_test(target)
+    libarchive_extract(target, tmp_path.joinpath("tgt2"))
+    #
+    with py7zr.SevenZipFile(target, "r") as arc:
+        arc.extractall(path=tmp_path / "tgt")