Treat unexpected errors as corrupt packages

A corrupt package is the most likely cause of an unexpected error, so
treat it as such.

dnf/rpm/miscutils.py

@@ -25,20 +25,20 @@
 from dnf.i18n import ucd
 from shutil import which
 
-sig_re = re.compile(b'\AV[34] (?:RSA|DSA|EdDSA|ECDSA)/SHA(256|384|512) Signature, key ID [0-9a-f]{8}\Z')
-payload_digest_re = re.compile(b'\APayload SHA(256|384|512) digest\Z')
+sig_re = re.compile(rb'\AV[34] (?:RSA|DSA|EdDSA|ECDSA)/SHA(256|384|512) Signature, key ID [0-9a-f]{8}\Z')
+payload_digest_re = re.compile(rb'\APayload SHA(256|384|512) digest\Z')
 
 def _process_rpm_output(data):
     if not data.startswith(b'-:\n') or not data.endswith(b'\n'):
-        _rpmkeys_parse_error()
+        return 2
     data = data.split(b'\n')[1:-1]
     if not data:
         return 2
     seen_sig, missing_key, not_trusted, not_signed = False, False, False, False
     valid = 0
     for i in data:
         if not i.startswith(b'    '):
-            _rpmkeys_parse_error()
+            return 2
         i = i[4:]
         if b': BAD' in i:
             return 2
@@ -56,7 +56,7 @@ def _process_rpm_output(data):
             elif payload_digest_re.match(i[:-4]):
                 valid |= 2
         else:
-            _rpmkeys_parse_error()
+            return 2
     if not_trusted:
         return 3
     elif missing_key:
@@ -87,9 +87,9 @@ def _verifyPackageUsingRpmkeys(package, installroot):
             stdin=package) as p:
         data, _ = p.communicate()
     if p.returncode >= 2 or p.returncode < 0:
-        _rpmkeys_parse_error()
+        return 2
     ret = _process_rpm_output(data)
-    if type(ret) is int and ret > 0:
+    if ret > 0:
         return ret
     return 2 if p.returncode else 0