Merge ~sylvain-pineau/checkbox-ng:allow-gzip-trailing-garbage into checkbox-ng:master

[Sylvain Pineau]

For unknown reasons, the record.gz files used to store job DiskResults can contain trailing garbage:

Betty encountered such issue and was unable to generate reports:

https://pastebin.ubuntu.com/p/HQ9TR2ZWPy/

The gzip archive was not actually corrupted since zcat was able to show the base64 content but it displayed a warning:

gzip: com.canonical.certification__stress_stress-ng-test-for-class-scheduler.record.gz: decompression OK, trailing garbage ignored

Actually there's a lot of issues reported against the gzip python module and currently there's no option to mimic a less strict mode as other gzip tools do (like gzip or zcat).

In such cases, our best option to continue processing results and finally create reports is simply to ignore such trailing garbage. This patch fixes our result.py module to allow this.

[Jonathan Cave (jocave)]

Looks fine

review: Approve

diff --git a/plainbox/impl/result.py b/plainbox/impl/result.py
index 3e0dea4..74fc1c0 100644
--- a/plainbox/impl/result.py
+++ b/plainbox/impl/result.py
@@ -564,7 +564,10 @@ class IOLogRecordReader:
         :returns: None if the stream is empty
         :returns: next :class:`IOLogRecord` as found in the stream.
         """
-        text = self.stream.readline()
+        try:
+            text = self.stream.readline()
+        except OSError:
+            return
         if len(text) == 0:
             return
         data = json.loads(text)