QMimeDatabase: don't stat() something that isn't a local file

We must check that the path is an actual file on the filesystem before
using native APIs. This regression was introduced by commit
047d8f36de45ebb318726167f941b0dbc64754ba.

[ChangeLog][QtCore][QMimeDatabase] Fixed a regression from 6.4.0 that
made certain QMimeDatabase functions that inspected file contents to fail
on Unix systems, if the file was not a native file (e.g., a Qt resource).

Fixes: QTBUG-110707
Pick-to: 6.4 6.5
Change-Id: I570832c9ac8b4e03bde8fffd173f7b4c6b164192
Reviewed-by: Igor Kushnir <igorkuo@gmail.com>
Reviewed-by: David Faure <david.faure@kdab.com>

4 files changed, 61 insertions, 0 deletions

diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-cache/CMakeLists.txt b/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-cache/CMakeLists.txt
index c32ad90437..589b129fad 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-cache/CMakeLists.txt
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-cache/CMakeLists.txt
@@ -48,6 +48,14 @@ qt_internal_add_resource(tst_qmimedatabase-cache "testdata"
         ${testdata_resource_files}
 )
 
+qt_internal_add_resource(tst_qmimedatabase-cache "testfiles"
+    PREFIX
+        "/files"
+    FILES
+        "../test.txt"
+        "../test.qml"
+)
+
 # special case begin
 set(corelib_source_dir ../../../../../../src/corelib)
 include(${corelib_source_dir}/mimetypes/mimetypes_resources.cmake)
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-xml/CMakeLists.txt b/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-xml/CMakeLists.txt
index 831e879764..a2633b5fec 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-xml/CMakeLists.txt
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/qmimedatabase-xml/CMakeLists.txt
@@ -48,6 +48,14 @@ qt_internal_add_resource(tst_qmimedatabase-xml "testdata"
         ${testdata_resource_files}
 )
 
+qt_internal_add_resource(tst_qmimedatabase-xml "testfiles"
+    PREFIX
+        "/files"
+    FILES
+        "../test.txt"
+        "../test.qml"
+)
+
 # special case begin
 set(corelib_source_dir ../../../../../../src/corelib)
 include(${corelib_source_dir}/mimetypes/mimetypes_resources.cmake)
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/test.txt b/tests/auto/corelib/mimetypes/qmimedatabase/test.txt
new file mode 100644
index 0000000000..752cf553e9
--- /dev/null
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/test.txt
@@ -0,0 +1,6 @@
+// Copyright (C) 2012 David Faure <faure@kde.org>
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+import QtQuick 1.1
+Item {
+}
diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
index 61a7682ac6..4145219bde 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
@@ -26,6 +26,8 @@
 #include <QProcess>
 #endif
 
+using namespace Qt::StringLiterals;
+
 static const char *const additionalMimeFiles[] = {
     "yast2-metapackage-handler-mimetypes.xml",
     "qml-again.xml",
@@ -246,6 +248,7 @@ void tst_QMimeDatabase::mimeTypeForFileName_data()
     // fdo bug 15436, needs shared-mime-info >= 0.40 (and this tests the globs2-parsing code).
     QTest::newRow("glob that ends with *, also matches *.pdf. *.pdf has higher weight") << "README.pdf" << "application/pdf";
     QTest::newRow("directory") << "/" << "inode/directory";
+    QTest::newRow("resource-directory") << ":/files/" << "inode/directory";
     QTest::newRow("doesn't exist, no extension") << "IDontExist" << "application/octet-stream";
     QTest::newRow("doesn't exist but has known extension") << "IDontExist.txt" << "text/plain";
     QTest::newRow("empty") << "" << "application/octet-stream";
@@ -498,6 +501,42 @@ void tst_QMimeDatabase::mimeTypeForFileWithContent()
         QCOMPARE(mime.name(), QString::fromLatin1("application/smil+xml"));
     }
 
+    // Test what happens with Qt resources (file engines in general)
+    {
+        QFile rccFile(":/files/test.txt");
+
+        mime = db.mimeTypeForFile(rccFile.fileName());
+        QCOMPARE(mime.name(), "text/plain"_L1);
+
+        QVERIFY(rccFile.open(QIODevice::ReadOnly));
+        mime = db.mimeTypeForData(&rccFile);
+        QCOMPARE(mime.name(), "text/x-qml"_L1);
+        QVERIFY(rccFile.isOpen());
+
+        mime = db.mimeTypeForFile(rccFile.fileName(), QMimeDatabase::MatchContent);
+        QCOMPARE(mime.name(), "text/x-qml"_L1);
+    }
+
+    // Directories
+    {
+        mime = db.mimeTypeForFile("/");
+        QCOMPARE(mime.name(), "inode/directory"_L1);
+
+        QString dirName = QDir::tempPath();
+        if (!dirName.endsWith(u'/'))
+            dirName += u'/';
+        mime = db.mimeTypeForFile(dirName);
+        QCOMPARE(mime.name(), "inode/directory"_L1);
+
+        while (dirName.endsWith(u'/'))
+            dirName.chop(1);
+        mime = db.mimeTypeForFile(dirName);
+        QCOMPARE(mime.name(), "inode/directory"_L1);
+
+        mime = db.mimeTypeForFile(":/files");
+        QCOMPARE(mime.name(), "inode/directory"_L1);
+    }
+
     // Test what happens with an incorrect path
     mime = db.mimeTypeForFile(QString::fromLatin1("file:///etc/passwd" /* incorrect code, use a path instead */));
     QVERIFY(mime.isDefault());