Add QMimeType::aliases().

Requested by Allan Sandfeld Jensen for QWebkit, which needs to register
upfront all the mimetypes that a given plugin can handle.

Change-Id: I64b8d39c7988adfc7db4ed8bfdc73acd16e999da
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/mimetypes/qmimeprovider.cpp

@@ -494,6 +494,29 @@ QString QMimeBinaryProvider::resolveAlias(const QString &name)
     return name;
 }
 
+QStringList QMimeBinaryProvider::listAliases(const QString &name)
+{
+    checkCache();
+    QStringList result;
+    const QByteArray input = name.toLatin1();
+    foreach (CacheFile *cacheFile, m_cacheFiles) {
+        const int aliasListOffset = cacheFile->getUint32(PosAliasListOffset);
+        const int numEntries = cacheFile->getUint32(aliasListOffset);
+        for (int pos = 0; pos < numEntries; ++pos) {
+            const int off = aliasListOffset + 4 + 8 * pos;
+            const int mimeOffset = cacheFile->getUint32(off + 4);
+            const char *mimeType = cacheFile->getCharStar(mimeOffset);
+
+            if (input == mimeType) {
+                const int aliasOffset = cacheFile->getUint32(off);
+                const char *alias = cacheFile->getCharStar(aliasOffset);
+                result.append(QString::fromLatin1(alias));
+            }
+        }
+    }
+    return result;
+}
+
 void QMimeBinaryProvider::loadMimeTypeList()
 {
     if (!m_mimetypeListLoaded) {
@@ -815,6 +838,13 @@ void QMimeXMLProvider::addParent(const QString &child, const QString &parent)
     m_parents[child].append(parent);
 }
 
+QStringList QMimeXMLProvider::listAliases(const QString &name)
+{
+    ensureLoaded();
+    // Iterate through the whole hash. This method is rarely used.
+    return m_aliases.keys(name);
+}
+
 QString QMimeXMLProvider::resolveAlias(const QString &name)
 {
     ensureLoaded();

src/corelib/mimetypes/qmimeprovider_p.h

@@ -61,6 +61,7 @@ public:
     virtual QStringList findByFileName(const QString &fileName, QString *foundSuffix) = 0;
     virtual QStringList parents(const QString &mime) = 0;
     virtual QString resolveAlias(const QString &name) = 0;
+    virtual QStringList listAliases(const QString &name) = 0;
     virtual QMimeType findByMagic(const QByteArray &data, int *accuracyPtr) = 0;
     virtual QList<QMimeType> allMimeTypes() = 0;
     virtual void loadMimeTypePrivate(QMimeTypePrivate &) {}
@@ -87,6 +88,7 @@ public:
     virtual QStringList findByFileName(const QString &fileName, QString *foundSuffix);
     virtual QStringList parents(const QString &mime);
     virtual QString resolveAlias(const QString &name);
+    virtual QStringList listAliases(const QString &name);
     virtual QMimeType findByMagic(const QByteArray &data, int *accuracyPtr);
     virtual QList<QMimeType> allMimeTypes();
     virtual void loadMimeTypePrivate(QMimeTypePrivate &);
@@ -128,6 +130,7 @@ public:
     virtual QStringList findByFileName(const QString &fileName, QString *foundSuffix);
     virtual QStringList parents(const QString &mime);
     virtual QString resolveAlias(const QString &name);
+    virtual QStringList listAliases(const QString &name);
     virtual QMimeType findByMagic(const QByteArray &data, int *accuracyPtr);
     virtual QList<QMimeType> allMimeTypes();
 

src/corelib/mimetypes/qmimetype.cpp

@@ -349,6 +349,22 @@ QStringList QMimeType::allAncestors() const
     return allParents;
 }
 
+/*!
+    Return the list of aliases of this mimetype.
+
+    For instance, for text/csv, the returned list would be:
+    text/x-csv, text/x-comma-separated-values.
+
+    Note that all QMimeType instances refer to proper mimetypes,
+    never to aliases directly.
+
+    The order of the aliases in the list is undefined.
+*/
+QStringList QMimeType::aliases() const
+{
+    return QMimeDatabasePrivate::instance()->provider()->listAliases(d->name);
+}
+
 /*!
     Returns the known suffixes for the MIME type.
     No leading dot is included, so for instance this would return "jpg", "jpeg" for image/jpeg.

src/corelib/mimetypes/qmimetype.h

@@ -90,6 +90,7 @@ public:
     QStringList globPatterns() const;
     QStringList parentMimeTypes() const;
     QStringList allAncestors() const;
+    QStringList aliases() const;
     QStringList suffixes() const;
     QString preferredSuffix() const;
 

tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp

@@ -355,6 +355,31 @@ void tst_QMimeDatabase::aliases()
     QVERIFY(!mustWriteMimeType);
 }
 
+void tst_QMimeDatabase::listAliases_data()
+{
+    QTest::addColumn<QString>("inputMime");
+    QTest::addColumn<QString>("expectedAliases");
+
+    QTest::newRow("csv") << "text/csv" << "text/x-csv,text/x-comma-separated-values";
+    QTest::newRow("xml") << "application/xml" << "text/xml";
+    QTest::newRow("xml2") << "text/xml" /* gets resolved to application/xml */ << "text/xml";
+    QTest::newRow("no_mime") << "message/news" << "";
+}
+
+void tst_QMimeDatabase::listAliases()
+{
+    QFETCH(QString, inputMime);
+    QFETCH(QString, expectedAliases);
+    QMimeDatabase db;
+    QStringList expectedAliasesList = expectedAliases.split(',', QString::SkipEmptyParts);
+    expectedAliasesList.sort();
+    QMimeType mime = db.mimeTypeForName(inputMime);
+    QVERIFY(mime.isValid());
+    QStringList aliasList = mime.aliases();
+    aliasList.sort();
+    QCOMPARE(aliasList, expectedAliasesList);
+}
+
 void tst_QMimeDatabase::icons()
 {
     QMimeDatabase db;

tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.h

@@ -62,6 +62,8 @@ private slots:
     void mimeTypesForFileName();
     void inheritance();
     void aliases();
+    void listAliases_data();
+    void listAliases();
     void icons();
     void mimeTypeForFileWithContent();
     void mimeTypeForUrl();