sddm/sddm-0.20.0-support-non-default-wayland-socket-names.patch

From df564d59533f9556d20f1141bf01de705cce3bf4 Mon Sep 17 00:00:00 2001
From: Aleksei Bavshin <alebastr89@gmail.com>
Date: Wed, 2 Feb 2022 23:08:59 -0800
Subject: [PATCH] WaylandHelper: support non-default display names

Weston v10[1] and some wlroots-based compositors[2][3] decided to stop
using `wayland-0`.
Extend WaylandSocketWatcher to look for any socket matching the
`wayland-?` pattern and pass the `WAYLAND_DISPLAY` to the greeter.

[1]: https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/486
[2]: https://github.com/swaywm/sway/commit/65a751a21f61b30808b7e703257c6ca3b71f50eb
[3]: https://github.com/WayfireWM/wayfire/commit/4ee4f3f259be00fd9a3c26960e8fce91ec526290
---
 src/helper/waylandhelper.cpp        |  5 +++-
 src/helper/waylandsocketwatcher.cpp | 37 +++++++++++++++++------------
 src/helper/waylandsocketwatcher.h   |  4 ++--
 3 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/src/helper/waylandhelper.cpp b/src/helper/waylandhelper.cpp
index 39952cb99..66d6b0796 100644
--- a/src/helper/waylandhelper.cpp
+++ b/src/helper/waylandhelper.cpp
@@ -119,7 +119,6 @@ void WaylandHelper::startGreeter(const QString &cmd)
     m_greeterProcess = new QProcess(this);
     m_greeterProcess->setProgram(args.takeFirst());
     m_greeterProcess->setArguments(args);
-    m_greeterProcess->setProcessEnvironment(m_environment);
     connect(m_greeterProcess, &QProcess::readyReadStandardError, this, [this] {
         qWarning() << m_greeterProcess->readAllStandardError();
     });
@@ -132,6 +131,8 @@ void WaylandHelper::startGreeter(const QString &cmd)
         QCoreApplication::instance()->quit();
     });
     if (m_watcher->status() == WaylandSocketWatcher::Started) {
+        m_environment.insert(QStringLiteral("WAYLAND_DISPLAY"), m_watcher->socketName());
+        m_greeterProcess->setProcessEnvironment(m_environment);
         m_greeterProcess->start();
     } else if (m_watcher->status() == WaylandSocketWatcher::Failed) {
         Q_EMIT failed();
@@ -139,6 +140,8 @@ void WaylandHelper::startGreeter(const QString &cmd)
         connect(m_watcher, &WaylandSocketWatcher::failed, this, &WaylandHelper::failed);
         connect(m_watcher, &WaylandSocketWatcher::started, this, [this] {
             m_watcher->stop();
+            m_environment.insert(QStringLiteral("WAYLAND_DISPLAY"), m_watcher->socketName());
+            m_greeterProcess->setProcessEnvironment(m_environment);
             m_greeterProcess->start();
         });
     }
diff --git a/src/helper/waylandsocketwatcher.cpp b/src/helper/waylandsocketwatcher.cpp
index 316690935..837bb189d 100644
--- a/src/helper/waylandsocketwatcher.cpp
+++ b/src/helper/waylandsocketwatcher.cpp
@@ -18,6 +18,7 @@
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 ***************************************************************************/
 
+#include <unistd.h>
 #include <QDebug>
 #include <QStandardPaths>
 
@@ -28,8 +29,9 @@ namespace SDDM {
 WaylandSocketWatcher::WaylandSocketWatcher(QObject *parent )
     : QObject(parent)
     , m_runtimeDir(QDir(QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation)))
-    , m_socketPath(m_runtimeDir.absoluteFilePath(QLatin1String("wayland-0")))
 {
+    m_runtimeDir.setFilter(QDir::Files | QDir::System);
+    m_runtimeDir.setNameFilters(QStringList() << QLatin1String("wayland-?"));
 }
 
 WaylandSocketWatcher::Status WaylandSocketWatcher::status() const
@@ -37,9 +39,9 @@ WaylandSocketWatcher::Status WaylandSocketWatcher::status() const
     return m_status;
 }
 
-QString WaylandSocketWatcher::socketPath() const
+QString WaylandSocketWatcher::socketName() const
 {
-    return m_socketPath;
+    return m_socketName;
 }
 
 void WaylandSocketWatcher::start()
@@ -53,8 +55,7 @@ void WaylandSocketWatcher::start()
         // Time is up and a socket was not found
         if (!m_watcher.isNull())
             m_watcher->deleteLater();
-        qWarning("Wayland socket watcher for \"%s\" timed out",
-                 qPrintable(m_socketPath));
+        qWarning("Wayland socket watcher timed out");
         m_status = Failed;
         Q_EMIT failed();
     });
@@ -62,22 +63,28 @@ void WaylandSocketWatcher::start()
     // Check if the socket exists
     connect(m_watcher, &QFileSystemWatcher::directoryChanged, this,
             [this](const QString &path) {
-        qDebug() << "Directory" << path << "has changed, checking for" << m_socketPath;
+        qDebug() << "Directory" << path << "has changed, checking for Wayland socket";
 
-        if (QFile::exists(m_socketPath)) {
-            m_timer.stop();
-            if (!m_watcher.isNull())
-                m_watcher->deleteLater();
-            m_status = Started;
-            Q_EMIT started();
+        m_runtimeDir.refresh();
+        const QFileInfoList fileInfoList = m_runtimeDir.entryInfoList();
+        for (const QFileInfo &fileInfo : fileInfoList) {
+            if (fileInfo.ownerId() == ::getuid()) {
+                qDebug() << "Found Wayland socket" << fileInfo.absoluteFilePath();
+                m_timer.stop();
+                if (!m_watcher.isNull())
+                    m_watcher->deleteLater();
+                m_socketName = fileInfo.fileName();
+                m_status = Started;
+                Q_EMIT started();
+                break;
+            }
         }
     });
 
     // Watch for runtime directory changes
     if (!m_runtimeDir.exists() || !m_watcher->addPath(m_runtimeDir.absolutePath())) {
-        qWarning("Cannot watch directory \"%s\" for Wayland socket \"%s\"",
-                 qPrintable(m_runtimeDir.absolutePath()),
-                 qPrintable(m_socketPath));
+        qWarning("Cannot watch directory \"%s\" for Wayland socket",
+                 qPrintable(m_runtimeDir.absolutePath()));
         m_watcher->deleteLater();
         m_status = Failed;
         Q_EMIT failed();
diff --git a/src/helper/waylandsocketwatcher.h b/src/helper/waylandsocketwatcher.h
index dfc5d214a..0032c1866 100644
--- a/src/helper/waylandsocketwatcher.h
+++ b/src/helper/waylandsocketwatcher.h
@@ -41,7 +41,7 @@ class WaylandSocketWatcher : public QObject
     explicit WaylandSocketWatcher(QObject *parent = nullptr);
 
     Status status() const;
-    QString socketPath() const;
+    QString socketName() const;
 
     void start();
     void stop();
@@ -54,7 +54,7 @@ class WaylandSocketWatcher : public QObject
 private:
     Status m_status = Stopped;
     QDir m_runtimeDir;
-    QString m_socketPath;
+    QString m_socketName;
     QTimer m_timer;
     QPointer<QFileSystemWatcher> m_watcher;
 };