kdiroperator: fix full file path not being stripped

QDir::isReadable always returns true for an unknown path if the
parent folder is readable, so use QFileInfo::isReadable instead.

Need to use QUrl::StripTrailingSlash and QUrl::RemoveFilename separately
since in QUrlPrivate::appendPath, QUrl::RemoveFilename is done before
QUrl::StripTrailingSlash.

BUG: 459900
FIXED-IN: 5.102

autotests/kdiroperatortest.cpp

@@ -258,6 +258,28 @@ private Q_SLOTS:
         QVERIFY(finishedSpy.wait(1000));
         QVERIFY(dirOp.selectedItems().isEmpty());
     }
+
+    /**
+     * If one copies the location of a file and then paste that into the location bar,
+     * the directory browser should show the directory of the file instead of showing an error.
+     * @see https://bugs.kde.org/459900
+     */
+    void test_bug459900()
+    {
+        KDirOperator dirOp;
+        QSignalSpy urlEnteredSpy(&dirOp, &KDirOperator::urlEntered);
+        // Try to open a file
+        const QString filePath = QFINDTESTDATA("servicemenu_protocol_mime_test_data/kio/servicemenus/mimetype_dir.desktop");
+        dirOp.setUrl(QUrl::fromLocalFile(filePath), true);
+        // Should accept the file and use its parent directory
+        QCOMPARE(urlEnteredSpy.size(), 1);
+        const QUrl fileUrl = QUrl::fromLocalFile(QFileInfo(filePath).absolutePath());
+        QCOMPARE(urlEnteredSpy.takeFirst().at(0).toUrl().adjusted(QUrl::StripTrailingSlash), fileUrl);
+        // Even in the same directory, KDirOperator should update the text in pathCombo
+        dirOp.setUrl(QUrl::fromLocalFile(filePath), true);
+        QCOMPARE(urlEnteredSpy.size(), 1);
+        QCOMPARE(urlEnteredSpy.takeFirst().at(0).toUrl().adjusted(QUrl::StripTrailingSlash), fileUrl.adjusted(QUrl::StripTrailingSlash));
+    }
 };
 
 QTEST_MAIN(KDirOperatorTest)

src/filewidgets/kdiroperator.cpp

@@ -971,8 +971,9 @@ void KDirOperator::setUrl(const QUrl &_newurl, bool clearforward)
 
     if (!d->isReadable(newurl)) {
         // maybe newurl is a file? check its parent directory
-        newurl = newurl.adjusted(QUrl::RemoveFilename | QUrl::StripTrailingSlash);
+        newurl = newurl.adjusted(QUrl::StripTrailingSlash).adjusted(QUrl::RemoveFilename);
         if (newurl.matches(d->m_currUrl, QUrl::StripTrailingSlash)) {
+            Q_EMIT urlEntered(newurl); // To remove the filename in pathCombo
             return; // parent is current dir, nothing to do (fixes #173454, too)
         }
         KIO::StatJob *job = KIO::stat(newurl);
@@ -3110,7 +3111,12 @@ bool KDirOperatorPrivate::isReadable(const QUrl &url)
     if (!url.isLocalFile()) {
         return true; // what else can we say?
     }
-    return QDir(url.toLocalFile()).isReadable();
+    const QFileInfo fileInfo(url.toLocalFile());
+#ifdef Q_OS_WIN
+    return fileInfo.isReadable() && fileInfo.isDir();
+#else
+    return fileInfo.isReadable();
+#endif
 }
 
 void KDirOperatorPrivate::slotDirectoryCreated(const QUrl &url)