Rewrite test, dynamically generating the .tar.gz file, with help from dstufft in #748.

setuptools/tests/test_archive_util.py

 # coding: utf-8
 
+import tarfile
+import io
+
 from setuptools.extern import six
 
 import pytest
@@ -12,41 +15,24 @@ def tarfile_with_unicode(tmpdir):
     """
     Create a tarfile containing only a file whose name is
     a zero byte file called testimäge.png.
-
-    TODO: Is it possible to generate this file programmatically?
     """
-    data = (
-        b'\x1f\x8b\x08\x00R\xfe\x9fW\x00\x03\xed\xd6AO\x13A\x14\x00'
-        b'\xe0\x11b\x8c\x8d\' z\xf02\x07=x\xd9\xce\xcc\xce\xec\xd4\xc3'
-        b'&\xa21\xb4X\\lI\xa3r0\xc3v\xc1\x8a\xec6\xcbbz3\x1cH\x80x\x93'
-        b'x\xeaQ\x12\x13\x0f$z\xd5\x13\x17\xa9U\x8e&\xfc\x06\x13\xff'
-        b'\x82\xb3\xa5\n\xb6J!\x16\x8c\xf0\xbed2\x9d\xd7\xe9v\xba\xb3'
-        b'\xafo\x8c\xe4\xa8\xaa\xa4=U\xf4\xc2\xa4\xf1 \xf2f\xa3\xd2\xcc'
-        b'\xfa\xcb)\xcf(\xfbS\xa8K\x08!\x16\xe78\xee\xa5%\x1a=a\xdb'
-        b'\xe3\x06FLL\x99\xe4R#\x9cbB%\xa5\x1c\xe1J\xb7\x16\xb0\x97'
-        b'\xb9\xd9H\x85z)\x8fT\xa8\xdc\xe0\xcf\xf3\xf4\xb4\xc9\xc9=\xae'
-        b'\xb3\xfdS\xf0\xcf\xfe?\xc1$.\xab\xe8\xa1m\xb4\xed~\x82\x11'
-        b'\xec\xea\xb1gS.\t%&e,\x8e\xa9\xdd1"S\tf\xe2\xfc\x8dt&{\xcf(zO'
-        b'lj\xe9]d\x8c\xec\n\x97\xfc\xc0\xe6\xdc\x12\x84\x9a2AS?\xc2\xfe'
-        b'\xe3\x92?m\xd3\xc4\xbf\xbe\x05\'Z\xfb\xbew\xff;:\xe5\xbf)dK\xfe'
-        b'\x0b*\x04\xc2\xa4\xfbKiw\xc2\xf3\x1f\x9d>\x7f\x06\xf5 4\xa2\\'
-        b'\xec\xe4\xf1]\xdc\x14\xc7\xd0Y\xdd\x98n\xefu\x8b\xc7\xdf\xf6w'
-        b'\xc9\xc1\xb1\xb1\\\xf3e\xfc\x89\xaan\xf9\x96)\xa7v\xe2\x17\xdc'
-        b'`\xc6(\x86Ay"\xa8\x18*\x8a\xc2\xd2\xc4\x9c~"\xf5\x9b\x95\xea'
-        b'\xeb\xc2\xf0\x95Z2][[t>\xd63\x9f\xb2K\x9b\x1b\xce\xed\xfa\x9d7'
-        b'\xb9W\x85\xdaH\xf6\xf3\x87z\xef\xd2\xe5\x17+\x03\xf3\x0b\xb9'
-        b'\xbe[}\xf3\xe7V\xab+h\xa8w\xbd\xecl\x86\xfd\xce\xf3\x9e/\xd7'
-        b'\x9e\xbe}\xb6|ih||uk\xeb>z\xb7v\xf1\xeb\xdf\xdf\xafcf\xa7\xfa'
-        b'\x1f\xde\xbf@\xc7\xfa\xcfEK\xfe[B\x10\xa8\xffGAW\xe9F\xfd\xefP'
-        b'\xfb\x894\x7f[\xfb\xcd\x14\xcef\xae\x0f\xe6tE/\xdc4\xdc\xd0'
-        b'\xd33\x02\xbf9\xcbJq}f\xe0t\xdf\'\x04~\x95\xeb0\x9c\x10\x8e'
-        b'\xd0a\xd7\xfeX\xa7\xfc\x8f\xf3\xe5\xd7\xfc\xe7\xc2\xe2P\xff'
-        b'\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
-        b'\x008\xa8\xef\xb1g\xe1Z\x00(\x00\x00'
-    )
+    tarobj = io.BytesIO()
+
+    with tarfile.open(fileobj=tarobj, mode="w:gz") as tgz:
+        data = b""
+
+        filename = "testimäge.png"
+        if six.PY2:
+            filename = filename.decode('utf-8')
+
+        t = tarfile.TarInfo(filename)
+        t.size = len(data)
+
+        tgz.addfile(t, io.BytesIO(data))
+
     target = tmpdir / 'unicode-pkg-1.0.tar.gz'
     with open(str(target), mode='wb') as tf:
-        tf.write(data)
+        tf.write(tarobj.getvalue())
     return str(target)