2 files changed, 25 insertions, 0 deletions
diff --git a/indra/newview/llfloaterluadebug.cpp b/indra/newview/llfloaterluadebug.cpp
index 60571d6247..6da28aef5e 100644
--- a/indra/newview/llfloaterluadebug.cpp
+++ b/indra/newview/llfloaterluadebug.cpp
@@ -41,6 +41,7 @@
 #include "llsdutil.h"
 #include "lua_function.h"
 #include "stringize.h"
+#include "tempset.h"
 
 
 LLFloaterLUADebug::LLFloaterLUADebug(const LLSD &key)
@@ -77,6 +78,17 @@ LLFloaterLUADebug::~LLFloaterLUADebug()
 
 void LLFloaterLUADebug::onExecuteClicked()
 {
+    // Empirically, running Lua code that indirectly invokes the
+    // "LLNotifications" listener can result (via mysterious labyrinthine
+    // viewer UI byways) in a recursive call to this handler. We've seen Bad
+    // Things happen to the viewer with a second call to runScriptLine() with
+    // the same cmd on the same LuaState.
+    if (mExecuting)
+    {
+        LL_DEBUGS("Lua") << "recursive call to onExecuteClicked()" << LL_ENDL;
+        return;
+    }
+    TempSet executing(mExecuting, true);
     mResultOutput->setValue("");
 
     std::string cmd = mLineInput->getText();
@@ -94,6 +106,12 @@ void LLFloaterLUADebug::onBtnBrowse()
 
 void LLFloaterLUADebug::onBtnRun()
 {
+    if (mExecuting)
+    {
+        LL_DEBUGS("Lua") << "recursive call to onBtnRun()" << LL_ENDL;
+        return;
+    }
+    TempSet executing(mExecuting, true);
     std::vector<std::string> filenames;
     std::string filepath = mScriptPath->getText();
     if (!filepath.empty())
@@ -105,6 +123,12 @@ void LLFloaterLUADebug::onBtnRun()
 
 void LLFloaterLUADebug::runSelectedScript(const std::vector<std::string> &filenames)
 {
+    if (mExecuting)
+    {
+        LL_DEBUGS("Lua") << "recursive call to runSelectedScript()" << LL_ENDL;
+        return;
+    }
+    TempSet executing(mExecuting, true);
     mResultOutput->setValue("");
 
     std::string filepath = filenames[0];
diff --git a/indra/newview/llfloaterluadebug.h b/indra/newview/llfloaterluadebug.h
index 7418174570..4d9e2fabca 100644
--- a/indra/newview/llfloaterluadebug.h
+++ b/indra/newview/llfloaterluadebug.h
@@ -66,6 +66,7 @@ private:
     LLLineEditor* mLineInput;
     LLLineEditor* mScriptPath;
     LuaState mState;
+    bool mExecuting{ false };
 };
 
 #endif  // LL_LLFLOATERLUADEBUG_H