#6117 Guard against stale nearby chat toast handles

1 files changed, 53 insertions, 6 deletions

diff --git a/indra/newview/llfloaterimnearbychathandler.cpp b/indra/newview/llfloaterimnearbychathandler.cpp
index 3f1fe50b73..e92672f684 100644
--- a/indra/newview/llfloaterimnearbychathandler.cpp
+++ b/indra/newview/llfloaterimnearbychathandler.cpp
@@ -145,6 +145,8 @@ protected:
 
     void    updateToastFadingTime();
 
+    LLToast* getToastFromPool();
+
     create_toast_panel_callback_t m_create_toast_panel_callback_t;
 
     bool    createPoolToast();
@@ -238,9 +240,19 @@ void LLFloaterIMNearbyChatScreenChannel::updateToastsLifetime()
     S32 seconds = gSavedSettings.getS32("NearbyToastLifeTime");
     toast_list_t::iterator it;
 
-    for(it = m_toast_pool.begin(); it != m_toast_pool.end(); ++it)
+    for(it = m_toast_pool.begin(); it != m_toast_pool.end();)
     {
-        (*it).get()->setLifetime(seconds);
+        LLToast* toast = it->get();
+        if (toast)
+        {
+            toast->setLifetime(seconds);
+            ++it;
+        }
+        else
+        {
+            LL_WARNS("NearbyChat") << "Discarding destroyed toast from pool" << LL_ENDL;
+            it = m_toast_pool.erase(it);
+        }
     }
 }
 
@@ -249,12 +261,38 @@ void LLFloaterIMNearbyChatScreenChannel::updateToastFadingTime()
     S32 seconds = gSavedSettings.getS32("NearbyToastFadingTime");
     toast_list_t::iterator it;
 
-    for(it = m_toast_pool.begin(); it != m_toast_pool.end(); ++it)
+    for(it = m_toast_pool.begin(); it != m_toast_pool.end();)
     {
-        (*it).get()->setFadingTime(seconds);
+        LLToast* toast = it->get();
+        if (toast)
+        {
+            toast->setFadingTime(seconds);
+            ++it;
+        }
+        else
+        {
+            LL_WARNS("NearbyChat") << "Discarding destroyed toast from pool" << LL_ENDL;
+            it = m_toast_pool.erase(it);
+        }
     }
 }
 
+LLToast* LLFloaterIMNearbyChatScreenChannel::getToastFromPool()
+{
+    while (!m_toast_pool.empty())
+    {
+        LLToast* toast = m_toast_pool.back().get();
+        m_toast_pool.pop_back();
+
+        if (toast)
+            return toast;
+
+        LL_WARNS("NearbyChat") << "Discarding destroyed toast from pool" << LL_ENDL;
+    }
+
+    return nullptr;
+}
+
 bool    LLFloaterIMNearbyChatScreenChannel::createPoolToast()
 {
     LLFloaterIMNearbyChatToastPanel* panel= m_create_toast_panel_callback_t();
@@ -344,9 +382,18 @@ void LLFloaterIMNearbyChatScreenChannel::addChat(LLSD& chat)
     //take 1st element from pool, (re)initialize it, put it in active toasts
 
     LL_DEBUGS("NearbyChat") << "Getting toast from pool" << LL_ENDL;
-    LLToast* toast = m_toast_pool.back().get();
+    LLToast* toast = getToastFromPool();
+    if (!toast)
+    {
+        // A toast can be destroyed while its handle remains in the pool.
+        // Replenish the pool instead of dereferencing the dead handle.
+        if (!createPoolToast())
+            return;
 
-    m_toast_pool.pop_back();
+        toast = getToastFromPool();
+        if (!toast)
+            return;
+    }
 
 
     LLFloaterIMNearbyChatToastPanel* panel = dynamic_cast<LLFloaterIMNearbyChatToastPanel*>(toast->getPanel());