support for Amiga protection bits and create_system

README.md

@@ -1,3 +1,11 @@
+Changes in this branch:
+- Support for Amiga protection bits
+- Support for archive create system
+
+Upstream README:
+
+
+
 # LHA archive support for Python
 
 The `lhafile` package is a python extension that handles .lha archives, with

lhafile/lhafile.py

@@ -215,11 +215,12 @@ def _RealGetContent(self):
                 filename, crc = unpack('<%dsH' % filename_length, fp.read(filename_length + 2))
             if os_level == 0:
                 ext_header_size = 0
+                os_identifier = None
                 pass
             elif os_level == 1:
                 extra_data_size = header_size - (5+4+4+2+2+1+1+1+filename_length+2+1+2)
                 os_identifier, extra_data, ext_header_size \
-                = unpack('<c%dsH' % extra_data_size, fp.read(1 + extra_data_size + 2))
+                = unpack('<B%dsH' % extra_data_size, fp.read(1 + extra_data_size + 2))
             sum_ext_header_size = 0
             directory = None
             comment = None
@@ -306,6 +307,25 @@ def _RealGetContent(self):
             directory = directory.decode("ISO-8859-1")
             directory = os.sep.join(directory.split('\xff'))
             filename = os.path.join(directory, filename)
+
+        # OSIDs based on
+        # http://dangan.g.dgdg.jp/en/Content/Program/Java/jLHA/Notes/OSID.html
+        os_identifiers = { 0x41: 'Amiga', 0x4D: 'MS-DOS', 0x32: 'OS/2', 0x39: 'OS-9',
+                          0x4B: 'OS/68K', 0x33: 'OS/386', 0x48: 'Human68K', 0x55: 'UNIX',
+                          0x43: 'CP/M', 0x46: 'FLEX', 0x6D: 'Macintosh', 0x52: 'Runser',
+                          0x54: 'TownOS', 0x58: 'XOSK', 0x77: 'Windows95', 0x57: 'WindowsNT',
+                          0x00: 'generic/MS-DOS', 0x4A: 'Java' }
+        create_system = os_identifiers.get(os_identifier, '')
+
+        # set protection bits for Amiga archives
+        if create_system == 'Amiga' or ( os_level == 0 and reserved not in (0x20, 0x80) ):
+            flag_bits_bin = bin(reserved ^ 0b00001111)[2:].zfill(8)
+            default_flags = 'hsparwed'
+            flag_bits = ''.join([ flag[1] if flag[0] == '1' else '-' for flag in zip(
+                                flag_bits_bin, default_flags)])
+        else:
+            flag_bits = None
+
         info.directory = directory
         info.filename = filename
         info.compress_size = compress_size
@@ -319,6 +339,8 @@ def _RealGetContent(self):
         info.comment = comment
         info.compress_type = signature
         info.date_time = date_time
+        info.create_system = create_system
+        info.flag_bits = flag_bits
 
         if "\x00" in info.filename:
             info.filename, info.comment = info.filename.split("\x00")