protocols/outputMgmt: fix wlr-randr by defering success event until monitor reloads (#12236)

wlr-randr disconnects immediately after receiving success event, but
before applying the monitor configuration. This causes the state to be
lost when performMonitorReload() is called.

By postponing the success event until the call of the hook
monitorLayoutChanged we ensure the configuration to remain valid during
the reload process.

2 files changed, 30 insertions, 2 deletions

diff --git a/src/protocols/OutputManagement.cpp b/src/protocols/OutputManagement.cpp
index 6cb2f474..6ae7c820 100644
--- a/src/protocols/OutputManagement.cpp
+++ b/src/protocols/OutputManagement.cpp
@@ -28,6 +28,8 @@ COutputManager::COutputManager(SP<CZwlrOutputManagerV1> resource_) : m_resource(
             PROTO::outputManagement->m_configurations.pop_back();
             return;
         }
+
+        RESOURCE->m_self = RESOURCE;
     });
 
     // send all heads at start
@@ -335,7 +337,7 @@ COutputConfiguration::COutputConfiguration(SP<CZwlrOutputConfigurationV1> resour
         const auto SUCCESS = applyTestConfiguration(false);
 
         if (SUCCESS)
-            m_resource->sendSucceeded();
+            PROTO::outputManagement->m_pendingConfigurationSuccessEvents.emplace_back(m_self);
         else
             m_resource->sendFailed();
 
@@ -576,7 +578,10 @@ bool COutputConfigurationHead::good() {
 }
 
 COutputManagementProtocol::COutputManagementProtocol(const wl_interface* iface, const int& ver, const std::string& name) : IWaylandProtocol(iface, ver, name) {
-    static auto P = g_pHookSystem->hookDynamic("monitorLayoutChanged", [this](void* self, SCallbackInfo& info, std::any param) { this->updateAllOutputs(); });
+    static auto P = g_pHookSystem->hookDynamic("monitorLayoutChanged", [this](void* self, SCallbackInfo& info, std::any param) {
+        updateAllOutputs();
+        sendPendingSuccessEvents();
+    });
 }
 
 void COutputManagementProtocol::bindManager(wl_client* client, void* data, uint32_t ver, uint32_t id) {
@@ -647,3 +652,19 @@ SP<SWlrManagerSavedOutputState> COutputManagementProtocol::getOutputStateFor(PHL
 
     return nullptr;
 }
+
+void COutputManagementProtocol::sendPendingSuccessEvents() {
+    if (m_pendingConfigurationSuccessEvents.empty())
+        return;
+
+    LOGM(LOG, "Sending {} pending configuration success events", m_pendingConfigurationSuccessEvents.size());
+
+    for (auto const& config : m_pendingConfigurationSuccessEvents) {
+        if (!config)
+            continue;
+
+        config->m_resource->sendSucceeded();
+    }
+
+    m_pendingConfigurationSuccessEvents.clear();
+}
diff --git a/src/protocols/OutputManagement.hpp b/src/protocols/OutputManagement.hpp
index cb03661e..f26e9c91 100644
--- a/src/protocols/OutputManagement.hpp
+++ b/src/protocols/OutputManagement.hpp
@@ -141,8 +141,12 @@ class COutputConfiguration {
     SP<CZwlrOutputConfigurationV1>            m_resource;
     std::vector<WP<COutputConfigurationHead>> m_heads;
     WP<COutputManager>                        m_owner;
+    WP<COutputConfiguration>                  m_self;
 
     bool                                      applyTestConfiguration(bool test);
+
+    friend class COutputManagementProtocol;
+    friend class COutputManager;
 };
 
 class COutputManagementProtocol : public IWaylandProtocol {
@@ -154,6 +158,8 @@ class COutputManagementProtocol : public IWaylandProtocol {
     // doesn't have to return one
     SP<SWlrManagerSavedOutputState> getOutputStateFor(PHLMONITOR pMonitor);
 
+    void                            sendPendingSuccessEvents();
+
   private:
     void destroyResource(COutputManager* resource);
     void destroyResource(COutputHead* resource);
@@ -169,6 +175,7 @@ class COutputManagementProtocol : public IWaylandProtocol {
     std::vector<SP<COutputMode>>              m_modes;
     std::vector<SP<COutputConfiguration>>     m_configurations;
     std::vector<SP<COutputConfigurationHead>> m_configurationHeads;
+    std::vector<WP<COutputConfiguration>>     m_pendingConfigurationSuccessEvents;
 
     SP<COutputHead>                           headFromResource(wl_resource* r);
     SP<COutputMode>                           modeFromResource(wl_resource* r);