Smart match of accented characters

Fix #1618

test/test_go.rb

@@ -1805,6 +1805,14 @@ class TestGoFZF < TestBase
     tmux.until { |lines| lines.item_count == 1 }
     tmux.until { |lines| assert_match %r{121.*121/1000}, lines[1] }
   end
+
+  def test_normalized_match
+    echoes = '(echo a; echo á; echo A; echo Á;)'
+    assert_equal %w[a á A Á], `#{echoes} | #{FZF} -f a`.lines.map(&:chomp)
+    assert_equal %w[á Á], `#{echoes} | #{FZF} -f á`.lines.map(&:chomp)
+    assert_equal %w[A Á], `#{echoes} | #{FZF} -f A`.lines.map(&:chomp)
+    assert_equal %w[Á], `#{echoes} | #{FZF} -f Á`.lines.map(&:chomp)
+  end
 end
 
 module TestShell