[kde-linux/package-compatibility-helper] src: Grant folder temporary access when a tool is sandboxed away from the file

Git commit 002edf6de6972a995ee9001f49a27b32b521bf4a by Hadi Chokr.
Committed on 18/08/2026 at 11:29.
Pushed by silverhadch into branch 'master'.

Grant folder temporary access when a tool is sandboxed away from the file

Closes #6 


Co-authored-by: Thomas Duckworth <[email protected]>
Signed-off-by: Hadi Chokr <[email protected]>

M  +76   -6    src/ICompatibilityHelper.cpp
M  +10   -2    src/ICompatibilityHelper.h
M  +10   -0    src/contents/ui/Main.qml

https://invent.kde.org/kde-linux/package-compatibility-helper/-/commit/002edf6de6972a995ee9001f49a27b32b521bf4a

diff --git a/src/ICompatibilityHelper.cpp b/src/ICompatibilityHelper.cpp
index a7c6c6e..814d83d 100644
--- a/src/ICompatibilityHelper.cpp
+++ b/src/ICompatibilityHelper.cpp
@@ -10,7 +10,11 @@
 #include <KIO/OpenUrlJob>
 #include <KLocalizedContext>
 #include <KLocalizedString>
+#include <KShell>
+#include <QDir>
+#include <QFileInfo>
 #include <QIcon>
+#include <QRegularExpression>
 
 #define DOCUMENTATION_URL QUrl(u"https://kde.org/linux/docs/more-software"_s)
 
@@ -25,9 +29,37 @@ void ICompatibilityHelper::openAppInAppStore(const QString &ref) const
     job->start();
 }
 
-void ICompatibilityHelper::openApp(const QString &ref, const QList<QUrl> &urls) const
+void ICompatibilityHelper::openApp(const QString &ref, const QList<QUrl> &urls, const QString &transientFolderAccess) const
 {
-    KIO::ApplicationLauncherJob *job = new KIO::ApplicationLauncherJob(KService::serviceByDesktopName(ref));
+    // Exported Flatpak entries spell out the path to flatpak, e.g.
+    // "/usr/bin/flatpak run --command=wine --file-forwarding org.winehq.Wine @@u %u @@".
+    static const QRegularExpression flatpakRun(u"^(?:\\S*/)?flatpak\\s+run\\s+"_s);
+    static const QRegularExpression fileForwarding(u"\\s--file-forwarding\\b|\\s@@u?(?=\\s|$)"_s);
+
+    KService::Ptr service = KService::serviceByDesktopName(ref);
+
+    if (service && !urls.isEmpty()) {
+        QString exec = service->exec();
+        const QRegularExpressionMatch match = flatpakRun.match(exec);
+
+        if (match.hasMatch()) {
+            // Document portal paths put the file in a directory of its own, so
+            // hand over the real path and open its folder instead.
+            exec.remove(fileForwarding);
+            exec.replace(u"%u"_s, u"%f"_s);
+            exec.replace(u"%U"_s, u"%F"_s);
+
+            // Amending the line keeps --branch, --arch and --command.
+            if (!transientFolderAccess.isEmpty()) {
+                exec.insert(match.capturedEnd(), u"--filesystem=%1:rw "_s.arg(KShell::quoteArg(transientFolderAccess)));
+            }
+            service->setExec(exec);
+        } else if (!transientFolderAccess.isEmpty()) {
+            qWarning() << "The desktop entry for" << ref << "does not launch a Flatpak, so its Exec line was left as-is:" << exec;
+        }
+    }
+
+    KIO::ApplicationLauncherJob *job = new KIO::ApplicationLauncherJob(service);
     job->setUiDelegate(KIO::createDefaultJobUiDelegate(KJobUiDelegate::AutoHandlingEnabled, nullptr));
     job->setUrls(urls);
     job->start();
@@ -204,6 +236,36 @@ QString ICompatibilityHelper::compatibilityToolActionIcon() const
     return m_compatibilityToolInstaller->icon();
 }
 
+QString ICompatibilityHelper::compatibilityToolWarning() const
+{
+    if (!hasCompatibilityTool()) {
+        return QString();
+    }
+
+    // With two tools on offer the user has not picked one yet, so don't name one.
+    if (hasSecondaryCompatibilityTool()) {
+        if (isCompatibilityToolInstalled() && isSecondaryCompatibilityToolInstalled()) {
+            return i18nc("@info",
+                         "Running this file temporarily gives the compatibility tool access to everything in this folder, in addition to its existing "
+                         "permissions. The file is not checked for safety. <b>Only run files from trusted sources.</b>");
+        }
+        return i18nc("@info",
+                     "Installing a compatibility tool and running this file with it temporarily gives it access to everything in this folder, in addition to "
+                     "the permissions it comes with. The file is not checked for safety. <b>Only run files from trusted sources.</b>");
+    }
+
+    if (isCompatibilityToolInstalled()) {
+        return i18nc("@info %1 is an application name, e.g. \"Wine\"",
+                     "Running this file temporarily gives %1 access to everything in this folder, in addition to its existing permissions. The file is not "
+                     "checked for safety. <b>Only run files from trusted sources.</b>",
+                     compatibilityToolName());
+    }
+    return i18nc("@info %1 is an application name, e.g. \"Wine\"",
+                 "Installing %1 and running this file with it temporarily gives it access to everything in this folder, in addition to the permissions it "
+                 "comes with. The file is not checked for safety. <b>Only run files from trusted sources.</b>",
+                 compatibilityToolName());
+}
+
 void ICompatibilityHelper::launchCompatibilityTool() const
 {
     if (!hasCompatibilityTool()) {
@@ -215,7 +277,7 @@ void ICompatibilityHelper::launchCompatibilityTool() const
         return;
     }
     m_compatibilityToolInstaller->takeOverMimeTypes();
-    openApp(m_compatibilityToolInstaller->appId(), {m_filePath});
+    openApp(m_compatibilityToolInstaller->appId(), {m_filePath}, fileFolder());
 }
 
 void ICompatibilityHelper::compatibilityToolInstallFinished() const
@@ -224,7 +286,7 @@ void ICompatibilityHelper::compatibilityToolInstallFinished() const
         return;
     }
     m_compatibilityToolInstaller->runPostInstall();
-    openApp(m_compatibilityToolInstaller->appId(), {m_filePath});
+    openApp(m_compatibilityToolInstaller->appId(), {m_filePath}, fileFolder());
 }
 
 bool ICompatibilityHelper::hasSecondaryCompatibilityTool() const
@@ -289,7 +351,7 @@ void ICompatibilityHelper::launchSecondaryCompatibilityTool() const
     }
     // Deliberately not calling takeOverMimeTypes() here: the secondary tool is
     // the non-default choice, so it should not claim the MIME type handler.
-    openApp(m_secondaryCompatibilityToolInstaller->appId(), {m_filePath});
+    openApp(m_secondaryCompatibilityToolInstaller->appId(), {m_filePath}, fileFolder());
 }
 
 void ICompatibilityHelper::secondaryCompatibilityToolInstallFinished() const
@@ -298,5 +360,13 @@ void ICompatibilityHelper::secondaryCompatibilityToolInstallFinished() const
         return;
     }
     m_secondaryCompatibilityToolInstaller->runPostInstall();
-    openApp(m_secondaryCompatibilityToolInstaller->appId(), {m_filePath});
+    openApp(m_secondaryCompatibilityToolInstaller->appId(), {m_filePath}, fileFolder());
+}
+
+QString ICompatibilityHelper::fileFolder() const
+{
+    if (!m_filePath.isValid() || !m_filePath.isLocalFile()) {
+        return QString();
+    }
+    return QDir::cleanPath(QFileInfo(m_filePath.toLocalFile()).absolutePath());
 }
diff --git a/src/ICompatibilityHelper.h b/src/ICompatibilityHelper.h
index 947a16d..7cd6992 100644
--- a/src/ICompatibilityHelper.h
+++ b/src/ICompatibilityHelper.h
@@ -48,6 +48,9 @@ class ICompatibilityHelper : public QObject
     Q_PROPERTY(bool compatibilityToolInstalled READ compatibilityToolInstalled CONSTANT)
     // The Flatpak installer configuration for the compatibility tool.
     Q_PROPERTY(QObject *compatibilityToolInstaller READ compatibilityToolInstaller CONSTANT)
+    // Warns about the folder access the tool is given and that the file itself
+    // is unchecked. Empty means no warning is shown.
+    Q_PROPERTY(QString compatibilityToolWarning READ compatibilityToolWarning CONSTANT)
 
     // A second, optional compatibility tool offered alongside the primary one.
     // Used when a file type could be handled by either of two tools and the two
@@ -86,6 +89,7 @@ public:
     virtual QString compatibilityToolActionIcon() const;
     bool compatibilityToolInstalled() const;
     QObject *compatibilityToolInstaller() const;
+    virtual QString compatibilityToolWarning() const;
     virtual bool hasSecondaryCompatibilityTool() const;
     QString secondaryCompatibilityToolActionText() const;
     QString secondaryCompatibilityToolActionIcon() const;
@@ -148,8 +152,9 @@ protected:
     // Helper that returns the name of the default app store, e.g. "Discover" or "Bazaar".
     QString appStoreName() const;
 
-    // Helper to open an app.
-    void openApp(const QString &ref, const QList<QUrl> &urls = {}) const;
+    // Helper to open an app. A folder named by transientFolderAccess is opened
+    // for it for that launch only.
+    void openApp(const QString &ref, const QList<QUrl> &urls = {}, const QString &transientFolderAccess = {}) const;
 
     // Helper to check if an app is installed.
     bool isAppInstalled(const QString &ref) const;
@@ -160,6 +165,9 @@ protected:
     // Helper to return the distro name.
     QString distroName() const;
 
+    // The folder the opened file is in, or an empty string in --install mode.
+    QString fileFolder() const;
+
     // The file path of the executable/package being opened.
     QUrl m_filePath;
 
diff --git a/src/contents/ui/Main.qml b/src/contents/ui/Main.qml
index 7f9e3fe..2dc1cc0 100644
--- a/src/contents/ui/Main.qml
+++ b/src/contents/ui/Main.qml
@@ -78,6 +78,7 @@ Kirigami.ApplicationWindow {
     // Measures the dimensions of the install page without triggering it.
     Loader {
         id: installPageMetrics
+        active: PackageCompatibilityHelper.hasCompatibilityTool
         visible: false
         sourceComponent: installPageMetricsComponent
     }
@@ -124,6 +125,15 @@ Kirigami.ApplicationWindow {
                         wrapMode: Text.WordWrap
                         text: PackageCompatibilityHelper.description
                     }
+
+                    Kirigami.InlineMessage {
+                        visible: PackageCompatibilityHelper.compatibilityToolWarning !== "" && !PackageCompatibilityHelper.hasNativeApp
+                        Layout.fillWidth: true
+                        Layout.maximumWidth: Math.max(Kirigami.Units.gridUnit * 30, heading.implicitWidth)
+                        Layout.topMargin: Kirigami.Units.smallSpacing
+                        type: Kirigami.MessageType.Warning
+                        text: PackageCompatibilityHelper.compatibilityToolWarning
+                    }
                 }
             }