Merge pull request #59 from yarikoptic/fixup/nested-gzip

Fixup/nested gzip

patoolib/__init__.py

@@ -25,7 +25,7 @@ import importlib
 from .configuration import App, Version as __version__
 __all__ = ['list_formats', 'list_archive', 'extract_archive', 'test_archive',
     'create_archive', 'diff_archives', 'search_archive', 'repack_archive',
-    'recompress_archive']
+    'recompress_archive', 'program_supports_compression']
 
 
 # Supported archive commands
@@ -285,6 +285,18 @@ ProgramModules = {
 }
 
 
+def program_supports_compression (program, compression):
+    """Decide if the given program supports the compression natively.
+    @return: True iff the program supports the given compression format
+      natively, else False.
+    """
+    if program in ('tar', ):
+        return compression in ('gzip', 'bzip2', 'xz', 'lzip', 'compress', 'lzma') + py_lzma
+    elif program in ('star', 'bsdtar', 'py_tarfile'):
+        return compression in ('gzip', 'bzip2') + py_lzma
+    return False
+
+
 from . import util
 
 def get_archive_format (filename):
@@ -337,16 +349,6 @@ def find_archive_program (format, command, program=None):
     raise util.PatoolError("could not find an executable program to %s format %s; candidates are (%s)," % (command, format, ",".join(programs)))
 
 
-def program_supports_compression (program, compression):
-    """Decide if the given program supports the compression natively.
-    @return: True iff the program supports the given compression format
-      natively, else False.
-    """
-    if program in ('tar', 'star', 'bsdtar', 'py_tarfile'):
-        return compression in ('gzip', 'bzip2') + py_lzma
-    return False
-
-
 def list_formats ():
     """Print information about available archive formats to stdout."""
     print("Archive programs of", App)

patoolib/util.py

@@ -24,7 +24,7 @@ import tempfile
 import time
 import traceback
 import locale
-from . import configuration, ArchiveMimetypes, ArchiveCompressions
+from . import configuration, ArchiveMimetypes, ArchiveCompressions, program_supports_compression
 try:
     from shutil import which
 except ImportError:
@@ -314,7 +314,12 @@ def guess_mime_file (filename):
         elif mime2 in ArchiveMimetypes:
             mime = mime2
             encoding = get_file_mime_encoding(outparts)
-    return mime, encoding
+    # Only return mime and encoding if the given mime can natively support the encoding.
+    if program_supports_compression(ArchiveMimetypes.get(mime), encoding):
+        return mime, encoding
+    else:
+        # If encoding is None, default back to `mime`.
+        return Encoding2Mime.get(encoding, mime), None
 
 
 def guess_mime_file_mime (file_prog, filename):

tests/__init__.py

@@ -34,7 +34,7 @@ def _need_func(testfunc, name, description):
     def check_func(func):
         def newfunc(*args, **kwargs):
             if not testfunc(name):
-                raise pytest.skip("%s %r is not available" % (description, name))
+                pytest.skip("%s %r is not available" % (description, name))
             return func(*args, **kwargs)
         setattr(newfunc, fnameattr, getattr(func, fnameattr))
         return newfunc
@@ -53,7 +53,7 @@ def needs_program(name):
 
 def needs_one_program(programs):
     """Decorator skipping test if not one of given programs are available."""
-    return _need_func(lambda x: all(map(patoolib.util.find_program, x)), programs, 'programs')
+    return _need_func(lambda x: any(map(patoolib.util.find_program, x)), programs, 'programs')
 
 
 def needs_module(name):
@@ -72,9 +72,9 @@ def needs_codec (program, codec):
     def check_prog (f):
         def newfunc (*args, **kwargs):
             if not patoolib.util.find_program(program):
-                raise pytest.skip("program `%s' not available" % program)
+                pytest.skip("program `%s' not available" % program)
             if not has_codec(program, codec):
-                raise pytest.skip("codec `%s' for program `%s' not available" % (codec, program))
+                pytest.skip("codec `%s' for program `%s' not available" % (codec, program))
             return f(*args, **kwargs)
         setattr(newfunc, fnameattr, getattr(f, fnameattr))
         return newfunc
@@ -95,7 +95,7 @@ def skip_on_travis():
     def check_func(func):
         def newfunc(*args, **kwargs):
             if "TRAVIS" in os.environ:
-                raise pytest.skip("Skip on TRAVIS CI build.")
+                pytest.skip("Skip on TRAVIS CI build.")
             return func(*args, **kwargs)
         setattr(newfunc, fnameattr, getattr(func, fnameattr))
         return newfunc

tests/archives/test_tar.py

@@ -69,6 +69,7 @@ class TestTar (ArchiveTest):
         self.archive_commands('t.tgz.foo', skip_create=True)
 
     @needs_program('file')
+    @needs_program('compress')
     @needs_codec(program, 'compress')
     def test_tar_z_file (self):
         self.archive_commands('t.tar.Z.foo', skip_create=True)

tests/test_mime.py

@@ -138,6 +138,7 @@ class TestMime (unittest.TestCase):
         self.mime_test_file("t.zpaq", "application/zpaq")
         self.mime_test_file("t.zpaq.foo", "application/zpaq")
 
+
     @needs_program('file')
     @needs_program('lzip')
     def test_mime_file_lzip (self):
@@ -149,6 +150,12 @@ class TestMime (unittest.TestCase):
         self.mime_test_file("t.tar.bz2.foo", "application/x-tar", "bzip2")
         self.mime_test_file("t.tbz2.foo", "application/x-tar", "bzip2")
 
+    @needs_program('file')
+    def test_nested_gzip (self):
+        # Ensure that a file that doesn't natively support encoding does not see the encoding
+        self.mime_test_file("t.rar.gz", "application/gzip")
+        self.mime_test_file("t.rar.gz.foo", "application/gzip")
+
     @needs_program('file')
     @needs_program('gzip')
     def test_mime_file_gzip (self):