Fixed obscure Lua errors in filtering and validating callbacks

Author: nickgammon

TextView.cpp

@@ -1504,14 +1504,13 @@ void CTextView::OpenLuaDelayed ()
 
   luaL_openlibs (L);           // open all standard Lua libraries
 
-  luaopen_rex (L);             // regular expression library
-  luaopen_bits (L);            // bit manipulation library
-  luaopen_compress (L);  // compression (utils) library
-  luaopen_progress_dialog (L); // progress dialog
-  luaopen_bc (L);   // open bc library   
-  luaopen_lsqlite3 (L);   // open sqlite library
-  lua_pushcfunction(L, luaopen_lpeg);   // open lpeg library
-  lua_call(L, 0, 0);
+  CallLuaCFunction (L, luaopen_rex);            // regular expression library
+  CallLuaCFunction (L, luaopen_bits);           // bit manipulation library
+  CallLuaCFunction (L, luaopen_compress);       // compression (utils) library
+  CallLuaCFunction (L, luaopen_progress_dialog);// progress dialog
+  CallLuaCFunction (L, luaopen_bc);             // open bc library   
+  CallLuaCFunction (L, luaopen_lsqlite3);       // open sqlite library
+  CallLuaCFunction (L, luaopen_lpeg);           // open lpeg library
 
   // add xml reader to utils lib
   luaL_register (L, "utils", ptr_xmllib);

dialogs/FunctionListDlg.cpp

@@ -26,6 +26,7 @@ CFunctionListDlg::CFunctionListDlg(CWnd* pParent /*=NULL*/)
   m_bFunctions = false;
   m_bNoSort = false;
   m_L = NULL;
+  m_iFilterIndex = LUA_NOREF;
 }
 
 
@@ -84,13 +85,13 @@ BOOL CFunctionListDlg::ReloadList ()
     string sValue = kv.sValue_;
     bool bWanted = false;
 
-    if (m_L && lua_type (m_L, 1) == LUA_TFUNCTION)
+   if (m_L && m_iFilterIndex != LUA_NOREF)
       {
 
+      lua_rawgeti (m_L, LUA_REGISTRYINDEX, m_iFilterIndex);
+
       // Lua filter:  function f (filter, key, value)  ... end
 
-      // filter function (make copy)
-      lua_pushvalue (m_L, 1);       
       // what they have currently typed
       lua_pushlstring (m_L, sFilter.c_str (), sFilter.size ());
 

dialogs/FunctionListDlg.h

@@ -39,6 +39,7 @@ class CFunctionListDlg : public CDialog
 
   // Lua state for filter function
   lua_State * m_L;
+  int m_iFilterIndex;
 
 // Overrides
 	// ClassWizard generated virtual function overrides

dialogs/LuaInputBox.cpp

@@ -28,6 +28,7 @@ CLuaInputBox::CLuaInputBox(CWnd* pParent /*=NULL*/)
 
   m_font = NULL;
   m_L = NULL;
+  m_iValidationIndex = LUA_NOREF;
 
 }
 
@@ -49,14 +50,14 @@ void CLuaInputBox::DoDataExchange(CDataExchange* pDX)
    }
 
 
- if (m_L && lua_type (m_L, -1) == LUA_TFUNCTION)
+ if (m_L && m_iValidationIndex != LUA_NOREF)
   {
   bool bWanted = false;
 
+  lua_rawgeti (m_L, LUA_REGISTRYINDEX, m_iValidationIndex);
+
   // Lua validation:  function f (value)  ... end
 
-  // validate function (make copy)
-  lua_pushvalue (m_L, -1);       
   // what they have currently typed
   lua_pushlstring (m_L, m_strReply, m_strReply.GetLength ());
 

dialogs/LuaInputBox.h

@@ -44,6 +44,7 @@ class CLuaInputBox : public CDialog
   CString m_strCancelbuttonLabel;
 
   lua_State *m_L;   // for validating
+  int m_iValidationIndex;  // where validation function is
 
 // Overrides
 	// ClassWizard generated virtual function overrides

dialogs/LuaInputEditDlg.cpp

@@ -28,6 +28,7 @@ CLuaInputEditDlg::CLuaInputEditDlg(CWnd* pParent /*=NULL*/)
 
   m_font = NULL;
   m_L = NULL;
+  m_iValidationIndex = LUA_NOREF;
 
 }
 
@@ -51,14 +52,14 @@ void CLuaInputEditDlg::DoDataExchange(CDataExchange* pDX)
    return;
    }
 
- if (m_L && lua_type (m_L, -1) == LUA_TFUNCTION)
+ if (m_L && m_iValidationIndex != LUA_NOREF)
   {
   bool bWanted = false;
 
+  lua_rawgeti (m_L, LUA_REGISTRYINDEX, m_iValidationIndex);
+
   // Lua validation:  function f (value)  ... end
 
-  // validate function (make copy)
-  lua_pushvalue (m_L, -1);       
   // what they have currently typed
   lua_pushlstring (m_L, m_strReply, m_strReply.GetLength ());
 

dialogs/LuaInputEditDlg.h

@@ -45,6 +45,7 @@ class CLuaInputEditDlg : public CDialog
   CString m_strCancelbuttonLabel;
 
   lua_State *m_L;   // for validating
+  int m_iValidationIndex;  // where validation function is
 
 // Overrides
 	// ClassWizard generated virtual function overrides

resource.h

@@ -1562,7 +1562,7 @@
 #ifdef APSTUDIO_INVOKED
 #ifndef APSTUDIO_READONLY_SYMBOLS
 #define _APS_3D_CONTROLS                     1
-#define _APS_NEXT_RESOURCE_VALUE        364
+#define _APS_NEXT_RESOURCE_VALUE        365
 #define _APS_NEXT_COMMAND_VALUE         33054
 #define _APS_NEXT_CONTROL_VALUE         2897
 #define _APS_NEXT_SYMED_VALUE           312

scripting/lua_utils.cpp

@@ -326,8 +326,6 @@ static int gen_inputbox (lua_State *L, T & msg)
   CString strOKbuttonLabel;
   CString strCancelbuttonLabel;
 
-
-
   // if arg6 present, and a table, grab extra stuff
   if (lua_istable (L, nExtraStuffArg))
     {
@@ -348,10 +346,15 @@ static int gen_inputbox (lua_State *L, T & msg)
     if (!lua_isnil (L, -1))
       {
       if (!lua_isfunction (L, -1))
-        luaL_error (L, "inputbox argument 6 value for 'validate' must be a function");
+        luaL_error (L, "inputbox argument #6 value for 'validate' must be a function");
 
       lua_pushvalue (L, -1);    // function is now on top of stack   
       msg.m_L = L;             // non-NULL indicates we have function there
+
+      // we can't leave the function on the stack, that gets cleared from time to time
+      // while the dialog box is running - so we store it in the registry and get the
+      // unique index back
+      msg.m_iValidationIndex = luaL_ref (L, LUA_REGISTRYINDEX);
       } // validate function there
 
     }  // table of extra stuff there
@@ -382,11 +385,16 @@ static int gen_inputbox (lua_State *L, T & msg)
   msg.m_strOKbuttonLabel      = strOKbuttonLabel ;
   msg.m_strCancelbuttonLabel  = strCancelbuttonLabel;
 
+  lua_settop (L, 0);
+
   if (msg.DoModal () != IDOK)
     lua_pushnil (L);
   else
     lua_pushstring (L, msg.m_strReply);
 
+  // free up registry entry  (is OK with LUA_NOREF)
+  luaL_unref(L, LUA_REGISTRYINDEX, msg.m_iValidationIndex);
+
   return 1;
 } // end of gen_inputbox
 
@@ -1754,11 +1762,15 @@ CFunctionListDlg dlg;
     if (!lua_isnil (L, 5))
       {
       luaL_checktype (L, 5, LUA_TFUNCTION);
-      lua_remove (L, 1);   // get rid of bottom 4 items
-      lua_remove (L, 1);
-      lua_remove (L, 1);
-      lua_remove (L, 1);
-      dlg.m_L = L;   // function is now at stack item 1
+      lua_pushvalue (L, 5);    // function is now on top of stack   
+
+      dlg.m_L = L; 
+
+      // we can't leave the function on the stack, that gets cleared from time to time
+      // while the dialog box is running - so we store it in the registry and get the
+      // unique index back
+      dlg.m_iFilterIndex = luaL_ref (L, LUA_REGISTRYINDEX);
+
       }
     }
 
@@ -1777,6 +1789,9 @@ CFunctionListDlg dlg;
       }
     }
 
+  // free up registry entry  (is OK with LUA_NOREF)
+  luaL_unref(L, LUA_REGISTRYINDEX, dlg.m_iFilterIndex);
+
   return 1;   // 1 result
 
 } // end of filterpicker