allow using the system Lua package path

plugins/MigrateFontSizes/main.lua

@@ -3,9 +3,6 @@ function initUi()
   app.registerUi({["menu"] = "Migrate font sizes with factor displayDPI / 72", ["callback"] = "migrate"});
   app.registerUi({["menu"] = "Show font size migration dialog", ["callback"] = "showDialog"});
 
-  lgiInstallPaths = "/usr/share/lua/5.3/?.lua; /usr/local/share/lua/5.3/?.lua" -- change this if your lgi.lua file is located in a different directory
-  package.path = package.path .. ";../?.lua;" .. lgiInstallPaths 
-
   sourcePath = debug.getinfo(1).source:match("@?(.*/)")
 end
 
@@ -25,7 +22,7 @@ local currDpi
 function showDialog()
   local hasLgi, lgi = pcall(require, "lgi")
   if not hasLgi then
-    app.msgbox("You need to have the Lua lgi-module installed in order to use the GUI for migrating font sizes. \n\n Also check the lgi module install paths in the file \n\n " .. sourcePath .. "main.lua \n\n Currently \n\n" .. lgiInstallPaths .. "\n\n is specified", {[1]="OK"})
+    app.msgbox("You need to have the Lua lgi-module installed and included in your Lua package path in order to use the GUI for migrating font sizes. \n\n", {[1]="OK"})
     return
   end
 

src/plugin/Plugin.cpp

@@ -166,17 +166,18 @@ void Plugin::addPluginToLuaPath() {
     // get field "path" from table at top of stack (-1)
     lua_getfield(lua.get(), -1, "path");
 
-    // For now: limit the include path to the current plugin folder, for security and compatibility reasons
     // grab path string from top of stack
-    // std::string curPath = lua_tostring(lua, -1);
-    // curPath.append(";");
-    auto curPath = path / "?.lua";
+    std::string luaPath = lua_tostring(lua.get(), -1);
 
-    // get rid of the std::string on the stack we just pushed on line 5
+    // prepend the path of the current plugin
+    auto curPath = this->path / "?.lua";
+    std::string combinedPath = curPath.string() + ";" + luaPath;
+
+    // get rid of the std::string on the stack we just pushed
     lua_pop(lua.get(), 1);
 
     // push the new one
-    lua_pushstring(lua.get(), curPath.string().c_str());
+    lua_pushstring(lua.get(), combinedPath.c_str());
 
     // set the field "path" in table at -2 with value at top of stack
     lua_setfield(lua.get(), -2, "path");