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-rw-r--r--src/corelib/io/qresource.cpp2
-rw-r--r--src/corelib/io/qtldurl.cpp2
-rw-r--r--src/corelib/tools/qhash.cpp30
-rw-r--r--src/corelib/tools/qhash.h1
4 files changed, 33 insertions, 2 deletions
diff --git a/src/corelib/io/qresource.cpp b/src/corelib/io/qresource.cpp
index fb3a24b940..4a0211c00a 100644
--- a/src/corelib/io/qresource.cpp
+++ b/src/corelib/io/qresource.cpp
@@ -673,7 +673,7 @@ int QResourceRoot::findNode(const QString &_path, const QLocale &locale) const
qDebug() << " " << child+j << " :: " << name(child+j);
}
#endif
- const uint h = qHash(segment);
+ const uint h = qt_hash(segment.toString());
//do the binary search for the hash
int l = 0, r = child_count-1;
diff --git a/src/corelib/io/qtldurl.cpp b/src/corelib/io/qtldurl.cpp
index 48df01b48c..efd663b09a 100644
--- a/src/corelib/io/qtldurl.cpp
+++ b/src/corelib/io/qtldurl.cpp
@@ -50,7 +50,7 @@ QT_BEGIN_NAMESPACE
static bool containsTLDEntry(const QString &entry)
{
- int index = qHash(entry) % tldCount;
+ int index = qt_hash(entry) % tldCount;
int currentDomainIndex = tldIndices[index];
while (currentDomainIndex < tldIndices[index+1]) {
QString currentEntry = QString::fromUtf8(tldData + currentDomainIndex);
diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index 6119c945fe..ce7d4ad098 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -222,6 +222,31 @@ static void qt_initialize_qhash_seed()
}
}
+/*!
+ \internal
+
+ Private copy of the implementation of the Qt 4 qHash algorithm for strings,
+ to be used wherever the result is somehow stored or reused across multiple
+ Qt versions. The public qHash implementation can change at any time,
+ therefore one must not rely on the fact that it will always give the same
+ results.
+
+ This function must *never* change its results.
+*/
+uint qt_hash(const QString &key)
+{
+ const QChar *p = key.unicode();
+ int n = key.size();
+ uint h = 0;
+
+ while (n--) {
+ h = (h << 4) + (*p++).unicode();
+ h ^= (h & 0xf0000000) >> 23;
+ h &= 0x0fffffff;
+ }
+ return h;
+}
+
/*
The prime_deltas array is a table of selected prime values, even
though it doesn't look like one. The primes we are using are 1,
@@ -817,6 +842,11 @@ void QHashData::checkSanity()
XOR'ed this with the day they were born to help produce unique
hashes for people with the same name.
+ Note that the implementation of the qHash() overloads offered by Qt
+ may change at any time. You \b{must not} rely on the fact that qHash()
+ will give the same results (for the same inputs) across different Qt
+ versions.
+
\section2 Algorithmic complexity attacks
All hash tables are vulnerable to a particular class of denial of service
diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 42c33f6f78..533208da85 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -89,6 +89,7 @@ Q_CORE_EXPORT uint qHash(const QString &key, uint seed = 0);
Q_CORE_EXPORT uint qHash(const QStringRef &key, uint seed = 0);
Q_CORE_EXPORT uint qHash(const QBitArray &key, uint seed = 0);
Q_CORE_EXPORT uint qHash(const QLatin1String &key, uint seed = 0);
+Q_CORE_EXPORT uint qt_hash(const QString &key);
#if defined(Q_CC_MSVC)
#pragma warning( push )