Merge branch 'close-subprocess-file-handles' into 'master'

make sure file-streams of subprocesses get closed

See merge request !328

fdroidserver/common.py

@@ -1804,6 +1804,12 @@ def FDroidPopenBytes(commands, cwd=None, envs=None, output=True, stderr_to_stdou
     result.returncode = p.wait()
     result.output = buf.getvalue()
     buf.close()
+    # make sure all filestreams of the subprocess are closed
+    for streamvar in ['stdin', 'stdout', 'stderr']:
+        if hasattr(p, streamvar):
+            stream = getattr(p, streamvar)
+            if stream:
+                stream.close()
     return result