File 0001-Process-all-available-auth-messages-in-a-loop.patch of Package sddm

From aaf9ee34dc0e2776a8177de14b5e6c880a5ffacf Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fabian@ritter-vogt.de>
Date: Tue, 4 Apr 2023 16:36:21 +0200
Subject: [PATCH] Process all available auth messages in a loop

When QLocalSocket::readyRead is emitted, it's important to read all available
data. Otherwise the event loop is reentered while data is still available and
readyRead won't be emitted again.

This can happen in practice if sddm-helper sends a message which does not
need a reply (e.g. INFO) followed by another message before the daemon
processed the first one. In that case the daemon would never process the second
one, potentially leaving sddm-helper waiting for a reply.

(cherry picked from commit 48a98c7ba45b49cf443ac46f0d218f044933c603)
---
 src/auth/Auth.cpp | 92 ++++++++++++++++++++++++-----------------------
 1 file changed, 47 insertions(+), 45 deletions(-)

diff --git a/src/auth/Auth.cpp b/src/auth/Auth.cpp
index c2228ae..9e132af 100644
--- a/src/auth/Auth.cpp
+++ b/src/auth/Auth.cpp
@@ -152,55 +152,57 @@ namespace SDDM {
         Auth *auth = qobject_cast<Auth*>(parent());
         Msg m = MSG_UNKNOWN;
         SafeDataStream str(socket);
-        str.receive();
-        str >> m;
-        switch (m) {
-            case ERROR: {
-                QString message;
-                Error type = ERROR_NONE;
-                str >> message >> type;
-                Q_EMIT auth->error(message, type);
-                break;
-            }
-            case INFO: {
-                QString message;
-                Info type = INFO_NONE;
-                str >> message >> type;
-                Q_EMIT auth->info(message, type);
-                break;
-            }
-            case REQUEST: {
-                Request r;
-                str >> r;
-                request->setRequest(&r);
-                break;
-            }
-            case AUTHENTICATED: {
-                QString user;
-                str >> user;
-                if (!user.isEmpty()) {
-                    auth->setUser(user);
-                    Q_EMIT auth->authentication(user, true);
+        while (socket->bytesAvailable() > 0) {
+            str.receive();
+            str >> m;
+            switch (m) {
+                case ERROR: {
+                    QString message;
+                    Error type = ERROR_NONE;
+                    str >> message >> type;
+                    Q_EMIT auth->error(message, type);
+                    break;
+                }
+                case INFO: {
+                    QString message;
+                    Info type = INFO_NONE;
+                    str >> message >> type;
+                    Q_EMIT auth->info(message, type);
+                    break;
+                }
+                case REQUEST: {
+                    Request r;
+                    str >> r;
+                    request->setRequest(&r);
+                    break;
+                }
+                case AUTHENTICATED: {
+                    QString user;
+                    str >> user;
+                    if (!user.isEmpty()) {
+                        auth->setUser(user);
+                        Q_EMIT auth->authentication(user, true);
+                        str.reset();
+                        str << AUTHENTICATED << environment << cookie;
+                        str.send();
+                    }
+                    else {
+                        Q_EMIT auth->authentication(user, false);
+                    }
+                    break;
+                }
+                case SESSION_STATUS: {
+                    bool status;
+                    str >> status;
+                    Q_EMIT auth->sessionStarted(status);
                     str.reset();
-                    str << AUTHENTICATED << environment << cookie;
+                    str << SESSION_STATUS;
                     str.send();
+                    break;
                 }
-                else {
-                    Q_EMIT auth->authentication(user, false);
+                default: {
+                    Q_EMIT auth->error(QStringLiteral("Auth: Unexpected value received: %1").arg(m), ERROR_INTERNAL);
                 }
-                break;
-            }
-            case SESSION_STATUS: {
-                bool status;
-                str >> status;
-                Q_EMIT auth->sessionStarted(status);
-                str.reset();
-                str << SESSION_STATUS;
-                str.send();
-                break;
-            }
-            default: {
-                Q_EMIT auth->error(QStringLiteral("Auth: Unexpected value received: %1").arg(m), ERROR_INTERNAL);
             }
         }
     }
-- 
2.40.0