QMimeDatabase: ensure mutex is locked in provider()

This wasn't the case when called from QMimeType, or some
QMimeDatabase methods. Now fixed.

Change-Id: Ifd515c1520482e4a23c399f1f773269659c92359
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 69 insertions, 20 deletions

diff --git a/src/corelib/mimetypes/qmimedatabase.cpp b/src/corelib/mimetypes/qmimedatabase.cpp
index 687f0b3e03..ed8bad0d83 100644
--- a/src/corelib/mimetypes/qmimedatabase.cpp
+++ b/src/corelib/mimetypes/qmimedatabase.cpp
@@ -81,6 +81,7 @@ QMimeDatabasePrivate::~QMimeDatabasePrivate()
 
 QMimeProviderBase *QMimeDatabasePrivate::provider()
 {
+    Q_ASSERT(!mutex.tryLock()); // caller should have locked mutex
     if (!m_provider) {
         QMimeProviderBase *binaryProvider = new QMimeBinaryProvider(this);
         if (binaryProvider->isValid()) {
@@ -93,12 +94,6 @@ QMimeProviderBase *QMimeDatabasePrivate::provider()
     return m_provider;
 }
 
-void QMimeDatabasePrivate::setProvider(QMimeProviderBase *theProvider)
-{
-    delete m_provider;
-    m_provider = theProvider;
-}
-
 /*!
     \internal
     Returns a MIME type or an invalid one if none found
@@ -118,6 +113,47 @@ QStringList QMimeDatabasePrivate::mimeTypeForFileName(const QString &fileName)
     return matchingMimeTypes;
 }
 
+QMimeGlobMatchResult QMimeDatabasePrivate::findByFileName(const QString &fileName)
+{
+    return provider()->findByFileName(fileName);
+}
+
+void QMimeDatabasePrivate::loadMimeTypePrivate(QMimeTypePrivate &mimePrivate)
+{
+    QMutexLocker locker(&mutex);
+    provider()->loadMimeTypePrivate(mimePrivate);
+}
+
+void QMimeDatabasePrivate::loadGenericIcon(QMimeTypePrivate &mimePrivate)
+{
+    QMutexLocker locker(&mutex);
+    provider()->loadGenericIcon(mimePrivate);
+}
+
+void QMimeDatabasePrivate::loadIcon(QMimeTypePrivate &mimePrivate)
+{
+    QMutexLocker locker(&mutex);
+    provider()->loadIcon(mimePrivate);
+}
+
+QStringList QMimeDatabasePrivate::parents(const QString &mimeName)
+{
+    QMutexLocker locker(&mutex);
+    return provider()->parents(mimeName);
+}
+
+QStringList QMimeDatabasePrivate::listAliases(const QString &mimeName)
+{
+    QMutexLocker locker(&mutex);
+    return provider()->listAliases(mimeName);
+}
+
+bool QMimeDatabasePrivate::mimeInherits(const QString &mime, const QString &parent)
+{
+    QMutexLocker locker(&mutex);
+    return inherits(mime, parent);
+}
+
 static inline bool isTextFile(const QByteArray &data)
 {
     // UTF16 byte order marks
@@ -460,7 +496,7 @@ QList<QMimeType> QMimeDatabase::mimeTypesForFileName(const QString &fileName) co
 QString QMimeDatabase::suffixForFileName(const QString &fileName) const
 {
     QMutexLocker locker(&d->mutex);
-    return d->provider()->findByFileName(QFileInfo(fileName).fileName()).m_foundSuffix;
+    return d->findByFileName(QFileInfo(fileName).fileName()).m_foundSuffix;
 }
 
 /*!
@@ -550,6 +586,7 @@ QMimeType QMimeDatabase::mimeTypeForUrl(const QUrl &url) const
 */
 QMimeType QMimeDatabase::mimeTypeForFileNameAndData(const QString &fileName, QIODevice *device) const
 {
+    QMutexLocker locker(&d->mutex);
     int accuracy = 0;
     const bool openedByUs = !device->isOpen() && device->open(QIODevice::ReadOnly);
     const QMimeType result = d->mimeTypeForFileNameAndData(fileName, device, &accuracy);
@@ -576,6 +613,7 @@ QMimeType QMimeDatabase::mimeTypeForFileNameAndData(const QString &fileName, QIO
 */
 QMimeType QMimeDatabase::mimeTypeForFileNameAndData(const QString &fileName, const QByteArray &data) const
 {
+    QMutexLocker locker(&d->mutex);
     QBuffer buffer(const_cast<QByteArray *>(&data));
     buffer.open(QIODevice::ReadOnly);
     int accuracy = 0;
diff --git a/src/corelib/mimetypes/qmimedatabase_p.h b/src/corelib/mimetypes/qmimedatabase_p.h
index 3f63f5f103..5dfcf31237 100644
--- a/src/corelib/mimetypes/qmimedatabase_p.h
+++ b/src/corelib/mimetypes/qmimedatabase_p.h
@@ -77,9 +77,6 @@ public:
 
     static QMimeDatabasePrivate *instance();
 
-    QMimeProviderBase *provider();
-    void setProvider(QMimeProviderBase *theProvider);
-
     inline QString defaultMimeType() const { return m_defaultMimeType; }
 
     bool inherits(const QString &mime, const QString &parent);
@@ -91,8 +88,22 @@ public:
     QMimeType mimeTypeForFileNameAndData(const QString &fileName, QIODevice *device, int *priorityPtr);
     QMimeType findByData(const QByteArray &data, int *priorityPtr);
     QStringList mimeTypeForFileName(const QString &fileName);
+    QMimeGlobMatchResult findByFileName(const QString &fileName);
+
+    // API for QMimeType. Takes care of locking the mutex.
+    void loadMimeTypePrivate(QMimeTypePrivate &mimePrivate);
+    void loadGenericIcon(QMimeTypePrivate &mimePrivate);
+    void loadIcon(QMimeTypePrivate &mimePrivate);
+    QStringList parents(const QString &mimeName);
+    QStringList listAliases(const QString &mimeName);
+    bool mimeInherits(const QString &mime, const QString &parent);
+
+private:
+    QMimeProviderBase *provider();
 
     mutable QMimeProviderBase *m_provider;
+
+public:
     const QString m_defaultMimeType;
     QMutex mutex;
 };
diff --git a/src/corelib/mimetypes/qmimetype.cpp b/src/corelib/mimetypes/qmimetype.cpp
index 28113babfe..668b22e7cf 100644
--- a/src/corelib/mimetypes/qmimetype.cpp
+++ b/src/corelib/mimetypes/qmimetype.cpp
@@ -256,7 +256,7 @@ QString QMimeType::name() const
  */
 QString QMimeType::comment() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadMimeTypePrivate(*d);
+    QMimeDatabasePrivate::instance()->loadMimeTypePrivate(*d);
 
     QStringList languageList;
     languageList << QLocale().name();
@@ -296,7 +296,7 @@ QString QMimeType::comment() const
  */
 QString QMimeType::genericIconName() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadGenericIcon(*d);
+    QMimeDatabasePrivate::instance()->loadGenericIcon(*d);
     if (d->genericIconName.isEmpty()) {
         // From the spec:
         // If the generic icon name is empty (not specified by the mimetype definition)
@@ -324,7 +324,7 @@ QString QMimeType::genericIconName() const
  */
 QString QMimeType::iconName() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadIcon(*d);
+    QMimeDatabasePrivate::instance()->loadIcon(*d);
     if (d->iconName.isEmpty()) {
         // Make default icon name from the mimetype name
         d->iconName = name();
@@ -344,7 +344,7 @@ QString QMimeType::iconName() const
  */
 QStringList QMimeType::globPatterns() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadMimeTypePrivate(*d);
+    QMimeDatabasePrivate::instance()->loadMimeTypePrivate(*d);
     return d->globPatterns;
 }
 
@@ -368,12 +368,12 @@ QStringList QMimeType::globPatterns() const
 */
 QStringList QMimeType::parentMimeTypes() const
 {
-    return QMimeDatabasePrivate::instance()->provider()->parents(d->name);
+    return QMimeDatabasePrivate::instance()->parents(d->name);
 }
 
 static void collectParentMimeTypes(const QString &mime, QStringList &allParents)
 {
-    const QStringList parents = QMimeDatabasePrivate::instance()->provider()->parents(mime);
+    const QStringList parents = QMimeDatabasePrivate::instance()->parents(mime);
     for (const QString &parent : parents) {
         // I would use QSet, but since order matters I better not
         if (!allParents.contains(parent))
@@ -425,7 +425,7 @@ QStringList QMimeType::allAncestors() const
 */
 QStringList QMimeType::aliases() const
 {
-    return QMimeDatabasePrivate::instance()->provider()->listAliases(d->name);
+    return QMimeDatabasePrivate::instance()->listAliases(d->name);
 }
 
 /*!
@@ -439,7 +439,7 @@ QStringList QMimeType::aliases() const
  */
 QStringList QMimeType::suffixes() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadMimeTypePrivate(*d);
+    QMimeDatabasePrivate::instance()->loadMimeTypePrivate(*d);
 
     QStringList result;
     for (const QString &pattern : qAsConst(d->globPatterns)) {
@@ -480,7 +480,7 @@ QString QMimeType::preferredSuffix() const
 */
 QString QMimeType::filterString() const
 {
-    QMimeDatabasePrivate::instance()->provider()->loadMimeTypePrivate(*d);
+    QMimeDatabasePrivate::instance()->loadMimeTypePrivate(*d);
     QString filter;
 
     if (!d->globPatterns.empty()) {
@@ -508,7 +508,7 @@ bool QMimeType::inherits(const QString &mimeTypeName) const
 {
     if (d->name == mimeTypeName)
         return true;
-    return QMimeDatabasePrivate::instance()->inherits(d->name, mimeTypeName);
+    return QMimeDatabasePrivate::instance()->mimeInherits(d->name, mimeTypeName);
 }
 
 #ifndef QT_NO_DEBUG_STREAM