Bug#879661: lintian: Fail to process ser-player due to invalid XML

[Niels Thykier <niels@thykier.net>]

Package: lintian
Version: 2.5.55
Severity: important

Spotted on lindsay.d.o:

"""
N: ----
N: Processing binary package ser-player (version 1.7.0-2, arch amd64) ...
/srv/lintian.debian.org/scratch/temp-lintian-lab-x6W9jEpWMx/pool/s/ser-player/ser-player_1.7.0-2_amd64_binary/unpacked/usr/share/metainfo/com.google.sites.ser-player.appdata.xml:23: parser error : Opening and ending tag mismatch: screenshots line 13 and component
</component>
            ^
/srv/lintian.debian.org/scratch/temp-lintian-lab-x6W9jEpWMx/pool/s/ser-player/ser-player_1.7.0-2_amd64_binary/unpacked/usr/share/metainfo/com.google.sites.ser-player.appdata.xml:24: parser error : Premature end of data in tag component line 2

^
XML::Simple called at /srv/lintian.debian.org/lintian/checks/appstream-metadata.pm line 91.
internal error: cannot run appstream-metadata check on package binary:ser-player/1.7.0-2/amd64
warning: skipping check of binary:ser-player/1.7.0-2/amd64
N: ----
"""

Looks like the appstream-metadata check is missing a guard for
handling invalid XML.

Thanks,
~Niels