D20844: KTar::KTarPrivate::readLonglink: Fix crash in malformed files

[Aleix Pol Gonzalez]

apol accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R243 KArchive

BRANCH
  arcpatch-D20844

REVISION DETAIL
  https://phabricator.kde.org/D20844

To: aacid, apol
Cc: apol, kde-frameworks-devel, michaelh, ngraham, bruns