fix(apt): fix compression when python-apt is available

When python-apt is available, and thus apt_pkg, the iter_paragraphs
method only accepts filehandles in python-debian 0.1.49. Contrary to
what the docs state, passing a filehandle to an encrypted file causes
a segmentation fault. Thus we need to treat it differently.

When dealing with compressed files we now decompress the file and never
us python-apt.

For python debian >= 1.0.0 this behavior is fixed, and the method also
accepts filenames. Debian bookworm still uses 0.1.49, so we have to
have this workaround for now.

Fixes: 2d070dc feat(apt): allow reading of compressed apt-cache files
Signed-off-by: Christoph Steiger <[email protected]>

Author: Urist-McGit

src/debsbom/apt/cache.py

@@ -125,7 +125,7 @@ def _parse_sources(
                 logger.debug(f"Parsing apt cache source packages: {sources_file}")
                 # TODO: in python-debian >= 1.0.0 it is possible to directly
                 # pass the filename of a compressed file when using apt_pkg
-                sources_raw = Packages.iter_paragraphs(content, use_apt_pkg=HAS_PYTHON_APT)
+                sources_raw = Packages.iter_paragraphs(content, use_apt_pkg=False)
                 for s in Repository._make_srcpkgs(sources_raw, srcpkg_filter):
                     yield s
         except (FileNotFoundError, IndexError, RuntimeError):
@@ -148,7 +148,7 @@ def _parse_packages(
                 content = stream_compressed_file(compressed_variant)
                 # TODO: in python-debian >= 1.0.0 it is possible to directly
                 # pass the filename of a compressed file when using apt_pkg
-                packages_raw = Packages.iter_paragraphs(content, use_apt_pkg=HAS_PYTHON_APT)
+                packages_raw = Packages.iter_paragraphs(content, use_apt_pkg=False)
                 logger.debug(f"Parsing apt cache binary packages: {packages_file}")
                 for s in Repository._make_binpkgs(packages_raw, binpkg_filter):
                     yield s