1 files changed, 26 insertions, 4 deletions

diff --git a/linden/indra/newview/llappviewerwin32.cpp b/linden/indra/newview/llappviewerwin32.cpp
index 2a6fd60..34e6d42 100644
--- a/linden/indra/newview/llappviewerwin32.cpp
+++ b/linden/indra/newview/llappviewerwin32.cpp
@@ -124,6 +124,27 @@ LONG WINAPI viewer_windows_exception_handler(struct _EXCEPTION_POINTERS *excepti
         return retval;
 }
 
+// Create app mutex creates a unique global windows object. 
+// If the object can be created it returns true, otherwise
+// it returns false. The false result can be used to determine 
+// if another instance of a second life app (this vers. or later)
+// is running.
+// *NOTE: Do not use this method to run a single instance of the app.
+// This is intended to help debug problems with the cross-platform 
+// locked file method used for that purpose.
+bool create_app_mutex()
+{
+        bool result = true;
+        LPCWSTR unique_mutex_name = L"SecondLifeAppMutex";
+        HANDLE hMutex;
+        hMutex = CreateMutex(NULL, TRUE, unique_mutex_name); 
+        if(GetLastError() == ERROR_ALREADY_EXISTS) 
+        {     
+                result = false;
+        }
+        return result;
+}
+
 //#define DEBUGGING_SEH_FILTER 1
 #if DEBUGGING_SEH_FILTER
 #       define WINMAIN DebuggingWinMain
@@ -151,6 +172,10 @@ int APIENTRY WINMAIN(HINSTANCE hInstance,
         
         viewer_app_ptr->setErrorHandler(LLAppViewer::handleViewerCrash);
 
+        // Set a debug info flag to indicate if multiple instances are running.
+        bool found_other_instance = !create_app_mutex();
+        gDebugInfo["FoundOtherInstanceAtStartup"] = LLSD::Boolean(found_other_instance);
+
         bool ok = viewer_app_ptr->init();
         if(!ok)
         {
@@ -204,11 +229,8 @@ int APIENTRY WINMAIN(HINSTANCE hInstance,
         //start updater
         if(LLAppViewer::sUpdaterInfo)
         {
-#if LL_WINDOWS
                 _spawnl(_P_NOWAIT, LLAppViewer::sUpdaterInfo->mUpdateExePath.c_str(), LLAppViewer::sUpdaterInfo->mUpdateExePath.c_str(), LLAppViewer::sUpdaterInfo->mParams.str().c_str(), NULL);
-#elif LL_DARWIN
-                system(LLAppViewer::sUpdaterInfo->mUpdateExePath.c_str());              /* Flawfinder: ignore */
-#endif
+
                 delete LLAppViewer::sUpdaterInfo ;
                 LLAppViewer::sUpdaterInfo = NULL ;
         }