Add bindings to change symlink read behavior.

Add bindings to change symlink read behavior. Unfortunately, libarchive
does not seem to have a way of getting the current setting, so only the
setter was implemented.

Closes: #132

Signed-off-by: Nicholas Vinson <nvinson234@gmail.com>

Author: nvinson

libarchive/ffi.py

@@ -35,6 +35,9 @@
 ARCHIVE_FAILED = -25  # Current operation cannot complete.
 ARCHIVE_FATAL = -30   # No more operations are possible.
 
+ARCHIVE_SYMLINK_MODE_HYBRID = 'H'
+ARCHIVE_SYMLINK_MODE_LOGICAL = 'L'
+ARCHIVE_SYMLINK_MODE_PHYSICAL = 'P'
 
 # Callback types
 
@@ -286,6 +289,9 @@ def get_write_filter_function(filter_name):
 ffi('read_disk_open', [c_archive_p, c_char_p], c_int, check_int)
 ffi('read_disk_open_w', [c_archive_p, c_wchar_p], c_int, check_int)
 ffi('read_disk_descend', [c_archive_p], c_int, check_int)
+ffi('read_disk_set_symlink_hybrid', [c_archive_p], c_int)
+ffi('read_disk_set_symlink_logical', [c_archive_p], c_int)
+ffi('read_disk_set_symlink_physical', [c_archive_p], c_int)
 
 # archive_read_data
 

libarchive/write.py

@@ -46,7 +46,7 @@ def add_entries(self, entries):
 
     def add_files(
         self, *paths, flags=0, lookup=False, pathname=None, recursive=True,
-        **attributes
+        symlink_mode=ffi.ARCHIVE_SYMLINK_MODE_PHYSICAL, **attributes
     ):
         """Read files through the OS and add them to the archive.
 
@@ -63,6 +63,11 @@ def add_files(
             recursive (bool):
                 when False, if a path in `paths` is a directory,
                 only the directory itself is added.
+            symlink_mode (enum):
+                Determines how symlinks are traversed. Valid options are
+                ARCHIVE_SYMLINK_MODE_HYBRID, ARCHIVE_SYMLINK_MODE_LOGICAL, and
+                ARCHIVE_SYMLINK_MODE_PHYSICAL as defined in the ffi module.
+                Default value matches default from libarchive.
             attributes (dict): passed to `ArchiveEntry.modify()`
 
         Raises:
@@ -79,6 +84,14 @@ def add_files(
         entry_p = entry._entry_p
         for path in paths:
             with new_archive_read_disk(path, flags, lookup) as read_p:
+                if (symlink_mode == ffi.ARCHIVE_SYMLINK_MODE_PHYSICAL):
+                    ffi.read_disk_set_symlink_physical(read_p)
+                elif (symlink_mode == ffi.ARCHIVE_SYMLINK_MODE_LOGICAL):
+                    ffi.read_disk_set_symlink_logical(read_p)
+                elif (symlink_mode == ffi.ARCHIVE_SYMLINK_MODE_HYBRID):
+                    ffi.read_disk_set_symlink_hybrid(read_p)
+                else:
+                    raise ValueError(f"Bad symlink mode value {value}")
                 while 1:
                     r = read_next_header2(read_p, entry_p)
                     if r == ARCHIVE_EOF: