Hard crash when scrolling in preset browser when preset list empty

[MattKalt]

(this is with 3.0.6 demo version, zynaddsubfx plugin) (running on Windows 10 64-bit)

How to replicate:

• open zynaddsubfx plugin in either terminal or Reaper
• hover mouse over "preset" tab to the right (should be empty since nothing is selected)
• scroll up or down

A cascade of error messages shows up and the plugin (along with Reaper) hard-crashes. Here's the text of the error message:

trace (most recent call last):
    [6] (unknown):0
    [5] /z/src/mruby-zest-build/src/mruby-widget-lib/mrblib/script.rb:702:in tick_events
    [4] /z/src/mruby-zest-build/src/mruby-widget-lib/mrblib/script.rb:415:in handle_events
    [3] /z/src/mruby-zest-build/mruby/mrblib/array.rb:17:in each
    [2] /z/src.huruby-zest-build/src/mruby-widget-lib/mrblib/script.rb:428:in handle_events
    [1] /z/src/mruby-zest-build/src/mruby-widget-lib/mrblib/script.rb:275:in handleScroll
/z/src/mruby-zest-build/src/mruby-widget-lib/mrblib/fcache.rb:13061:in onScroll: undefined method 'length' (NoMethodError)

This issue is not present if the preset list is not empty

Let me know if I can provide more info

[fundamental]

Fixed via https://github.com/mruby-zest/mruby-zest-build/commit/9c37f2cad91827fce0162d20487d73486669d0ae Thanks for the report :+1: