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This is an automatically generated e-mail. To reply, visit:
<a href="https://git.reviewboard.kde.org/r/120150/">https://git.reviewboard.kde.org/r/120150/</a>
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<p style="margin-top: 0;">On September 12th, 2014, 11:08 p.m. UTC, <b>Kevin Funk</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">I've just a closer look at the code. It looks indeed unsafe to delete patch source which are <em style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: normal;">no</em> LocalPatchSources, (because others may access dangling pointers then, see 'showVcsDiff' function).</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">But: Is the <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">deleteLater</code> still necessary now? Is checking against <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">qobject_cast<LocalPatchSource*></code> and then just delete'ing not enough?</p></pre>
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<p>On September 12th, 2014, 11:49 p.m. UTC, <b>René J.V. Bertin</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">TBH, that's a bit over my head ... what does <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">qobject_cast<LocalPatchSource*></code> do? The code currently checks if it returns true to delete/deleteLater <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">m_patch</code>, isn't that the case when <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">m_patch</code> IS a LocalPatchSource?</p>
<p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Also, if access through a dangling pointer, e.g. by showVcsDiff, were to explain the crashes I've seen, why would it not crash on Linux too? Unless that's a result of differences in event handling, which kind of takes us back to my own hunch...</p></pre>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">Yes, it could crash on Linux, too. We've seen many reports about crashes in this code base so it could easily be that there are even more issues hidden in it. Generally though, it might be a race or memory corruption which might or might not crash randomly. Generally, we could try to cleanup the codebase and use smartpointers or direct QObject parent/child relationships to prevent such issues.</p></pre>
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<p>- Milian</p>
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<p>On September 12th, 2014, 8:30 p.m. UTC, René J.V. Bertin wrote:</p>
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<div>Review request for KDE Software on Mac OS X, KDevelop and Olivier Goffart.</div>
<div>By René J.V. Bertin.</div>
<p style="color: grey;"><i>Updated Sept. 12, 2014, 8:30 p.m.</i></p>
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<b style="color: #575012; font-size: 10pt;">Repository: </b>
kdevplatform
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">In https://reviewboard.kde.org/r/120081/ I proposed an (accepted) approach to prevent kdevelop from crashing after closing the patch review ("git/show differences") toolview. I had another of those crashes after heavier-than-usual perusal of the toolview, despite the previous patch. The attached patch replaces all <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">delete</code>s of <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">QObject</code> derived class instances with <code style="text-rendering: inherit;color: #4444cc;padding: 0;white-space: normal;margin: 0;line-height: inherit;">deleteLater()</code>.</p></pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;"><p style="padding: 0;text-rendering: inherit;margin: 0;line-height: inherit;white-space: inherit;">kdevplatform git/kde4-legacy on KDE/MacPorts OS X 10.6.8 . </p></pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>plugins/patchreview/patchreview.cpp <span style="color: grey">(18b63db)</span></li>
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<p><a href="https://git.reviewboard.kde.org/r/120150/diff/" style="margin-left: 3em;">View Diff</a></p>
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