D14413: subversion plugin: fix ThreadWeaver job lifetime race condition

[Friedrich W. H. Kossebau]

kossebau created this revision.
kossebau added a reviewer: KDevelop.
Restricted Application added a project: KDevelop.
Restricted Application added a subscriber: kdevelop-devel.
kossebau requested review of this revision.

REVISION SUMMARY
  The old code had the internal ThreadWeaver job being killed via the QObject
  child memory management from the outer KJob-based job object.
  Though this was done based on a signal emitted from the ThreadWeaver
  execution thread, when the internal ThreadWeaver job was still going to be
  used by the internal reference in the execution completion code.
  
  While the actual current ThreadWeaver code then is not accessing any member
  data and just using the pointer to the otherwisse already deleted object,
  this at least is not liked by ASan which detects a heap-use-after-free,
  resulting e.g. in failing unit tests on CI now and then.
  
  This patch fixes this by passing the ThreadWeaver job instance via a
  QSHaredPointer which then is shared by both the parent KJob and the
  ThreadWeaver Queue, so the deletion will be done by the last one handling
  it.

TEST PLAN
  Subversion plugin still works for what I tested, unit tests still pass.

REPOSITORY
  R32 KDevelop

BRANCH
  fixsvnjobaccessafterdelete

REVISION DETAIL
  https://phabricator.kde.org/D14413

AFFECTED FILES
  plugins/subversion/svnblamejob.cpp
  plugins/subversion/svndiffjob.cpp
  plugins/subversion/svninfojob.cpp
  plugins/subversion/svninternaljobbase.cpp
  plugins/subversion/svninternaljobbase.h
  plugins/subversion/svnjobbase.cpp
  plugins/subversion/svnjobbase.h
  plugins/subversion/svnlogjob.cpp
  plugins/subversion/svnstatusjob.cpp

To: kossebau, #kdevelop
Cc: kdevelop-devel, antismap, iodelay, vbspam, njensen, geetamc, Pilzschaf, akshaydeo, surgenight, arrowd
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