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| author | Mårten Nordheim <marten.nordheim@qt.io> | 2021-06-16 11:40:04 +0200 |
|---|---|---|
| committer | Qt Cherry-pick Bot <cherrypick_bot@qt-project.org> | 2021-06-18 09:49:58 +0000 |
| commit | 66aa4c86f4303dba48910c39ed0908818bf5dc6f (patch) | |
| tree | 6bbf085cc046ad479fd63193232dbe322c0c86e0 /src | |
| parent | 9f459dee1fb7b2fd429e827a0195c4e9a39003b2 (diff) | |
QHash: Fix erase() edge-case
When the element you want to erase is the last element AND the
next element (element 0), when rehashed, would be relocated to the last
element, this leads to the state below. Which is similar to a test in
tst_qhash for some seeds.
auto it = hash.begin + (hash.size - 1)
it = hash.erase(it)
it != hash.end
By forcing the iterator to increment if we were erasing the last element
we always end up with a pointer which is equal to hash.end
Befriend the tst_qhash class so we can set the seed to a known-bad one
Change-Id: Ie0b175003a2acb175ef5e3ab5a984e010f65d986
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
(cherry picked from commit ea7d87b5b59ded22b145ecbb4dd648ecfd1abbdd)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
Diffstat (limited to 'src')
| -rw-r--r-- | src/corelib/tools/qhash.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h index 4fb68ba0b5..1a793e6163 100644 --- a/src/corelib/tools/qhash.h +++ b/src/corelib/tools/qhash.h @@ -51,6 +51,8 @@ #include <initializer_list> #include <functional> // for std::hash +class tst_QHash; // for befriending + QT_BEGIN_NAMESPACE struct QHashDummyValue @@ -680,7 +682,7 @@ struct Data } // return correct position of the next element - if (!spans[span].hasNode(index)) + if (bucket == numBuckets - 1 || !spans[span].hasNode(index)) ++it; return it; } @@ -740,6 +742,7 @@ class QHash using Data = QHashPrivate::Data<Node>; friend class QSet<Key>; friend class QMultiHash<Key, T>; + friend tst_QHash; Data *d = nullptr; |