QMimeType: Use default key as fallback for comment() property

When QMimeProvider parses the shared mime database xml files,
it will read the <comment> element for mime comment and treat the
`xml:lang` attribute as locale language string. When no `xml:lang`
attr is provided, QMimeProvider will read the value and treat it as
a en_US locale string as the default key.

When we call QMimeType::comment(), it will try to get the locale
comment string with the default language (QLocale().name()), once
it can't find a matched result, it should return the default key
(which QMimeProvider set it as en_US locale before) as fallback.

Task-number: QTBUG-71314
Change-Id: I444f8159d6f19dfef6338cd79312f608d8f13394
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
index 597d51e7e0..9df52887f7 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
@@ -992,6 +992,20 @@ void tst_QMimeDatabase::installNewGlobalMimeType()
     const QString fooTestFile2 = QLatin1String(RESOURCE_PREFIX "magic-and-hierarchy2.foo");
     QCOMPARE(db.mimeTypeForFile(fooTestFile2).name(), QString::fromLatin1("application/vnd.qnx.bar-descriptor"));
 
+    // Test if we can use the default comment
+    {
+        struct RestoreLocale
+        {
+            ~RestoreLocale() { QLocale::setDefault(QLocale::c()); }
+        } restoreLocale;
+
+        QLocale::setDefault(QLocale("zh_CN"));
+        QMimeType suseymp = db.mimeTypeForName("text/x-suse-ymp");
+        QVERIFY(suseymp.isValid());
+        QCOMPARE(suseymp.comment(),
+                 QString::fromLatin1("YaST Meta Package"));
+    }
+
     // Now test removing the mimetype definitions again
     for (int i = 0; i < m_additionalMimeFileNames.size(); ++i)
         QFile::remove(destDir + m_additionalMimeFileNames.at(i));