Prevent infinite loops if plugin state save calls SaveState

Author: nickgammon

plugins.cpp

@@ -165,6 +165,7 @@ CPlugin::CPlugin (CMUSHclientDoc * pDoc)
   m_bGlobal = false;
   m_iLoadOrder = 0;
   m_iScriptTimeTaken = 0;
+  m_bSavingStateNow = false;
 
   } // end of constructor
 
@@ -784,9 +785,15 @@ bool bError = true;
   CPlugin * oldPlugin = m_pDoc->m_CurrentPlugin;
   m_pDoc->m_CurrentPlugin = this;
 
+  // prevent infinite loops
+  m_bSavingStateNow = true;
+
   CScriptCallInfo callinfo (ON_PLUGIN_SAVE_STATE, m_PluginCallbacks [ON_PLUGIN_SAVE_STATE]);
   ExecutePluginScript (callinfo);
 
+  // are not saving state now
+  m_bSavingStateNow = false;
+
   strFilename += m_pDoc->m_strWorldID;    // world ID
   strFilename += "-";
   strFilename += m_strID;                 // plugin ID

plugins.h

@@ -103,6 +103,7 @@ class CPlugin :public CObject
   bool m_bGlobal;               // true if plugin was loaded from global prefs
   long m_iLoadOrder;            // sequence in which plugins are processed
   LONGLONG m_iScriptTimeTaken;  // time taken to execute scripts
+  bool m_bSavingStateNow;       // to prevent infinite loops
 
   // Lua note - for Lua the DISPID is a flag indicating whether or not
   // the routine exists. It is set to DISPID_UNKNOWN if the last call caused an error

scripting/methods/methods_plugins.cpp

@@ -500,6 +500,11 @@ long CMUSHclientDoc::SaveState()
   if (!m_CurrentPlugin)                            
 	  return eNotAPlugin;                       
 
+  // if we are already saving the state, don't do it again
+  if (m_CurrentPlugin->m_bSavingStateNow) 
+    return ePluginCouldNotSaveState;
+
+  // save the state
   if (m_CurrentPlugin->SaveState (true))
     return ePluginCouldNotSaveState;