oeqa/core/case.py: Encode binary data of log

Do not decode the log content into a string only to re-encode it as
binary data again. Some logs might un-intentionally contain bytes that
do not decode as utf-8, as such preserve the log file content as it was
on disk.

Handle the decoding on the resulttool side, but also handle the failure
to decode the data.

(From OE-Core rev: 20531dc0b8f76a6e37cc856f36cd94077b6aba50)

Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/resulttool/resultutils.py

@@ -126,7 +126,11 @@ def decode_log(logdata):
         if "compressed" in logdata:
             data = logdata.get("compressed")
             data = base64.b64decode(data.encode("utf-8"))
-            return zlib.decompress(data).decode("utf-8")
+            data = zlib.decompress(data)
+            try:
+                return data.decode("utf-8")
+            except UnicodeDecodeError:
+                return data
     return None
 
 def ptestresult_get_log(results, section):