Fixed string conversion warning in lua_where

Added LoadFromFile unit test

Lua.API.pas

@@ -742,7 +742,7 @@ begin
     lua_getinfo(L, 'Sl', ar);  // get info about it
     if (ar.currentline > 0) then // is there info?
     begin
-      msg := Format('%s:%d: ', [ar.short_src, ar.currentline]);
+      msg := AnsiString(Format('%s:%d: ', [ar.short_src, ar.currentline]));
       lua_pushlstring(L, PAnsiChar(msg), Length(msg));
       exit
     end;

UnitTests/source/TestWrapper.pas

@@ -54,12 +54,15 @@ type
 
     procedure RegisterObject;
     procedure RegisterObjectTable;
+
+    procedure LoadFromFile;
   end;
 
 
 implementation
 uses
-  System.Classes;
+  System.Classes,
+  System.IOUtils;
 
 
 type
@@ -500,6 +503,30 @@ begin
 end;
 
 
+procedure TTestWrapper.LoadFromFile;
+var
+  fileName: string;
+  script: TStringList;
+
+begin
+  fileName := TPath.GetTempFileName;
+  try
+    script := TStringList.Create;
+    try
+      script.Add('print("Hello world!")');
+      script.SaveToFile(fileName);
+    finally
+      FreeAndNil(script);
+    end;
+
+    Lua.LoadFromFile(fileName);
+    CheckEquals('Hello world!', Printed.ToString);
+  finally
+    TFile.Delete(fileName);
+  end;
+end;
+
+
 { TTestObject }
 constructor TTestObject.Create(AOutput: TStringBuilder);
 begin