Read documents that have no relationships part

lib/docx/document.rb

@@ -113,6 +113,9 @@ def hyperlinks
     end
 
     def hyperlink_relationships
+      # @rels is nil when the document has no relationships part (#192)
+      return Nokogiri::XML::NodeSet.new(Nokogiri::XML::Document.new) unless @rels
+
       @rels.xpath("//xmlns:Relationship[contains(@Type,'hyperlink')]")
     end
 

spec/docx/document_spec.rb

@@ -157,6 +157,22 @@
       expect { doc.hyperlinks }.not_to raise_error
       expect(doc.hyperlinks).to be_a(Hash)
     end
+
+    # Regression tests for #192
+    context 'when the document has no relationships part' do
+      let(:doc) do
+        described_class.open(fixture_without('basic.docx', 'word/_rels/document.xml.rels'))
+      end
+
+      it 'is empty' do
+        expect(doc.hyperlinks).to eq({})
+      end
+
+      it 'still reads the document' do
+        expect(doc.paragraphs.map(&:text)).to eq(%w[hello world])
+        expect(doc.to_html).to include('hello')
+      end
+    end
   end
 
   describe '#document_properties' do

spec/support/fixture_helpers.rb

@@ -9,6 +9,21 @@ def fixture_path(name)
     File.join(FIXTURES_DIR, name)
   end
 
+  # The binary contents of fixture +name+ with the given zip entries left out,
+  # for testing documents that lack a part (open it with Docx::Document.open).
+  def fixture_without(name, *excluded_entries)
+    Zip::File.open(fixture_path(name)) do |zip|
+      Zip::OutputStream.write_buffer do |out|
+        zip.each do |entry|
+          next if !entry.file? || excluded_entries.include?(entry.name)
+
+          out.put_next_entry(entry.name)
+          out.write(zip.read(entry.name))
+        end
+      end.string
+    end
+  end
+
   # A path inside a per-example temporary directory, so saved documents never
   # land in spec/fixtures and are always cleaned up.
   def tmp_path(name)