Fix ToUnicode generation

lib/prawn/fonts/to_unicode_cmap.rb

@@ -140,7 +140,7 @@ def mapping_spans(mapping)
               discontinuous_slices
                 .flatten(1) # Join together
                 .slice_when { |a, b| (b[0] - a[0]) != 1 } # Slice at key discontinuity, again
-                .map { |span| span.length > 1 ? [:index_sorted, span] : [:short, slice] } +
+                .map { |span| span.length > 1 ? [:index_sorted, span] : [:short, span] } +
                 continuous_slices.map { |span| [:fully_sorted, span] }
             end
           } # rubocop: disable Style/MultilineBlockChain

spec/prawn/fonts/to_unicode_cmap_spec.rb

@@ -70,7 +70,7 @@
     expect(cmap).to include("beginbfrange\n<20><22><0030>\n")
   end
 
-  it 'uses ranges for continuous code rnages with non-continuous mappings' do
+  it 'uses ranges for continuous code ranges with non-continuous mappings' do
     cmap = described_class.new(0x20 => 0x32, 0x21 => 0x31, 0x22 => 0x30).generate
 
     expect(cmap).to include("beginbfrange\n<20><22>[<0032><0031><0030>]\n")
@@ -82,6 +82,13 @@
     expect(cmap).to include("beginbfchar\n<30><0040>\n")
   end
 
+  it 'splits mappings to continuous and non-coninuous code ranges' do
+    cmap = described_class.new(0x20 => 0x30, 0x21 => 0x31, 0x22 => 0x33).generate
+
+    expect(cmap).to include("beginbfrange\n<20><21><0030>\n")
+    expect(cmap).to include("beginbfchar\n<22><0033>\n")
+  end
+
   it 'splits continuous mappings into groups of 100' do
     mapping = (1..142).flat_map { |n| Array.new(3) { |i| [(n * 10) + i, (n * 10) + i] } }.to_h
     cmap = described_class.new(mapping).generate