Removing item in preprocessor does not update dependencies

[denisdefreyne]

Steps to reproduce

Use the following setup, where one main item includes all parts:

    FileUtils.mkdir_p('content')
    FileUtils.mkdir_p('content/parts')

    File.write('content/main.erb', 'Stuff')
    File.write('content/parts/a.txt', "---\ndraft: false\n---\nPart A")
    File.write('content/parts/b.txt', "---\ndraft: false\n---\nPart B")

    File.write('Rules', <<~CONTENT)
      preprocess do
        @items.delete_if { |i| i[:draft] }
      end

      compile '/*.erb' do
        filter :erb
        write ext: 'txt'
      end

      compile '/**/*.txt' do
        write ext: 'txt'
      end
    CONTENT

    File.write('content/main.erb', '<%= @items.find_all("/parts/*").map(&:compiled_content).sort.join("\n") %>')

Compile. output/main.txt will contain both parts A and B.

Mark a part as draft:

    File.write('content/parts/b.txt', "---\ndraft: true\n---\nPart B")

Compile.

Expected behavior

output/main.txt will contain only part A.

Actual behavior

output/main.txt will contain both parts A and B.

Details

…

Crash log

n/a