QMimeDatabase: fix handling of glob-deleteall

Binary provider:
  It was not possible to remove the first glob in a local override,
  because the mainPattern handling would re-add the first glob back.

XML provider:
  It didn't support glob-deleteall.
  Also, the order of the providers was wrong. We want to pick local
  overrides first, the internal DB has to go last in the list.

Fixes: QTBUG-85436
Pick-to: 5.15
Change-Id: I9a4523f37cd962c730df9a6ed992bd01c075bf03
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/mimetypes/qmimedatabase.cpp

@@ -101,27 +101,13 @@ void QMimeDatabasePrivate::loadProviders()
     const auto fdoIterator = std::find_if(mimeDirs.constBegin(), mimeDirs.constEnd(), [](const QString &mimeDir) -> bool {
         return QFileInfo::exists(mimeDir + QStringLiteral("/packages/freedesktop.org.xml")); }
     );
+    const bool needInternalDB = QMimeXMLProvider::InternalDatabaseAvailable && fdoIterator == mimeDirs.constEnd();
     //qDebug() << "mime dirs:" << mimeDirs;
 
     Providers currentProviders;
     std::swap(m_providers, currentProviders);
 
-    if (QMimeXMLProvider::InternalDatabaseAvailable && fdoIterator == mimeDirs.constEnd()) {
-        m_providers.reserve(mimeDirs.size() + 1);
-        // Check if we already have a provider for the InternalDatabase
-        const auto isInternal = [](const std::unique_ptr<QMimeProviderBase> &prov)
-        {
-            return prov && prov->isInternalDatabase();
-        };
-        const auto it = std::find_if(currentProviders.begin(), currentProviders.end(), isInternal);
-        if (it == currentProviders.end()) {
-            m_providers.push_back(Providers::value_type(new QMimeXMLProvider(this, QMimeXMLProvider::InternalDatabase)));
-        } else {
-            m_providers.push_back(std::move(*it));
-        }
-    } else {
-        m_providers.reserve(mimeDirs.size());
-    }
+    m_providers.reserve(mimeDirs.size() + (needInternalDB ? 1 : 0));
 
     for (const QString &mimeDir : mimeDirs) {
         const QString cacheFile = mimeDir + QStringLiteral("/mime.cache");
@@ -158,6 +144,21 @@ void QMimeDatabasePrivate::loadProviders()
             m_providers.push_back(std::move(provider));
         }
     }
+    // mimeDirs is sorted "most local first, most global last"
+    // so the internal XML DB goes at the end
+    if (needInternalDB) {
+        // Check if we already have a provider for the InternalDatabase
+        const auto isInternal = [](const std::unique_ptr<QMimeProviderBase> &prov)
+        {
+            return prov && prov->isInternalDatabase();
+        };
+        const auto it = std::find_if(currentProviders.begin(), currentProviders.end(), isInternal);
+        if (it == currentProviders.end()) {
+            m_providers.push_back(Providers::value_type(new QMimeXMLProvider(this, QMimeXMLProvider::InternalDatabase)));
+        } else {
+            m_providers.push_back(std::move(*it));
+        }
+    }
 }
 
 const QMimeDatabasePrivate::Providers &QMimeDatabasePrivate::providers()
@@ -215,7 +216,6 @@ QStringList QMimeDatabasePrivate::mimeTypeForFileName(const QString &fileName)
 QMimeGlobMatchResult QMimeDatabasePrivate::findByFileName(const QString &fileName)
 {
     QMimeGlobMatchResult result;
-    // TODO this parses in the order (local, global). Check that it handles "NOGLOBS" correctly.
     for (const auto &provider : providers())
         provider->addFileNameMatches(fileName, result);
     return result;

src/corelib/mimetypes/qmimeprovider.cpp

@@ -542,6 +542,7 @@ void QMimeBinaryProvider::loadMimeTypePrivate(QMimeTypePrivate &data)
                     data.iconName = xml.attributes().value(QLatin1String("name")).toString();
                 } else if (tag == QLatin1String("glob-deleteall")) { // as written out by shared-mime-info >= 0.70
                     data.globPatterns.clear();
+                    mainPattern.clear();
                 } else if (tag == QLatin1String("glob")) { // as written out by shared-mime-info >= 0.70
                     const QString pattern = xml.attributes().value(QLatin1String("pattern")).toString();
                     if (mainPattern.isEmpty() && pattern.startsWith(QLatin1Char('*'))) {

src/corelib/mimetypes/qmimetypeparser.cpp

@@ -63,6 +63,7 @@ static const char genericIconTagC[] = "generic-icon";
 static const char iconTagC[] = "icon";
 static const char nameAttributeC[] = "name";
 static const char globTagC[] = "glob";
+static const char globDeleteAllTagC[] = "glob-deleteall";
 static const char aliasTagC[] = "alias";
 static const char patternAttributeC[] = "pattern";
 static const char weightAttributeC[] = "weight";
@@ -123,6 +124,7 @@ QMimeTypeParserBase::ParseState QMimeTypeParserBase::nextState(ParseState curren
     case ParseGenericIcon:
     case ParseIcon:
     case ParseGlobPattern:
+    case ParseGlobDeleteAll:
     case ParseSubClass:
     case ParseAlias:
     case ParseOtherMimeTypeSubTag:
@@ -137,6 +139,8 @@ QMimeTypeParserBase::ParseState QMimeTypeParserBase::nextState(ParseState curren
             return ParseIcon;
         if (startElement == QLatin1String(globTagC))
             return ParseGlobPattern;
+        if (startElement == QLatin1String(globDeleteAllTagC))
+            return ParseGlobDeleteAll;
         if (startElement == QLatin1String(subClassTagC))
             return ParseSubClass;
         if (startElement == QLatin1String(aliasTagC))
@@ -242,6 +246,9 @@ bool QMimeTypeParserBase::parse(QIODevice *dev, const QString &fileName, QString
                 data.addGlobPattern(pattern); // just for QMimeType::globPatterns()
             }
                 break;
+            case ParseGlobDeleteAll:
+                data.globPatterns.clear();
+                break;
             case ParseSubClass: {
                 const QString inheritsFrom = atts.value(QLatin1String(mimeTypeAttributeC)).toString();
                 if (!inheritsFrom.isEmpty())

src/corelib/mimetypes/qmimetypeparser_p.h

@@ -90,6 +90,7 @@ private:
         ParseGenericIcon,
         ParseIcon,
         ParseGlobPattern,
+        ParseGlobDeleteAll,
         ParseSubClass,
         ParseAlias,
         ParseMagic,

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

@@ -985,11 +985,10 @@ void tst_QMimeDatabase::installNewGlobalMimeType()
     QCOMPARE(db.mimeTypeForFile(qmlTestFile).name(),
              QString::fromLatin1("text/x-qml"));
 
-    // ensure we can access the empty glob list
     {
         QMimeType objcsrc = db.mimeTypeForName(QStringLiteral("text/x-objcsrc"));
         QVERIFY(objcsrc.isValid());
-        qDebug() << objcsrc.globPatterns();
+        QCOMPARE(objcsrc.globPatterns(), QStringList());
     }
 
     const QString fooTestFile = QLatin1String(RESOURCE_PREFIX "magic-and-hierarchy.foo");
@@ -1066,6 +1065,12 @@ void tst_QMimeDatabase::installNewLocalMimeType()
     QCOMPARE(db.mimeTypeForName(QLatin1String("text/x-SuSE-ymu")).comment(), QString("URL of a YaST Meta Package"));
     checkHasMimeType("text/x-suse-ymp");
 
+    { // QTBUG-85436
+        QMimeType objcsrc = db.mimeTypeForName(QStringLiteral("text/x-objcsrc"));
+        QVERIFY(objcsrc.isValid());
+        QCOMPARE(objcsrc.globPatterns(), QStringList());
+    }
+
     // Test that a double-definition of a mimetype doesn't lead to sniffing ("conflicting globs").
     const QString qmlTestFile = QLatin1String(RESOURCE_PREFIX "test.qml");
     QVERIFY2(!qmlTestFile.isEmpty(),