substitute leaves placeholders unfilled, or garbles the line, in files saved by LibreOffice #187

require "docx"
require "zip"

W = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
PARAGRAPHS = [
  # 1. One run with two w:t around a line break (LibreOffice writes Shift+Enter this way).
  '<w:r><w:t>Name: {{name}}</w:t><w:br/><w:t>Next line</w:t></w:r>',
  # 2. Placeholder split across runs; the last run holds a w:t, w:br, w:t.
  '<w:r><w:t xml:space="preserve">Name: {{na</w:t></w:r><w:r><w:t>me}}</w:t><w:br/><w:t>Next line</w:t></w:r>',
  # 3. A run with several w:t in the middle of the match.
  '<w:r><w:t xml:space="preserve">A {{n</w:t></w:r><w:r><w:t>a</w:t><w:tab/><w:t>m</w:t></w:r><w:r><w:t xml:space="preserve">e}} B</w:t></w:r>',
  # 4. A hyperlink with two runs.
  '<w:r><w:t xml:space="preserve">See </w:t></w:r><w:hyperlink w:anchor="x"><w:r><w:t xml:space="preserve">site </w:t></w:r><w:r><w:t>{{na</w:t></w:r></w:hyperlink><w:r><w:t xml:space="preserve">me}} end</w:t></w:r>',
  # 5. A trailing space moved into a w:t that lacks xml:space="preserve".
  '<w:r><w:t>{{na</w:t></w:r><w:r><w:t xml:space="preserve">me}} </w:t></w:r><w:r><w:t>end</w:t></w:r>',
]
Zip::File.open("repro.docx", create: true) do |zip|
  zip.get_output_stream("[Content_Types].xml") { it.write %(<?xml version="1.0"?><Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"><Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/><Default Extension="xml" ContentType="application/xml"/><Override PartName="/word/document.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"/></Types>) }
  zip.get_output_stream("_rels/.rels") { it.write %(<?xml version="1.0"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="word/document.xml"/></Relationships>) }
  zip.get_output_stream("word/_rels/document.xml.rels") { it.write %(<?xml version="1.0"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"/>) }
  zip.get_output_stream("word/styles.xml") { it.write %(<?xml version="1.0"?><w:styles xmlns:w="#{W}"/>) }
  zip.get_output_stream("word/document.xml") { it.write %(<?xml version="1.0"?><w:document xmlns:w="#{W}"><w:body>#{PARAGRAPHS.map { "<w:p>#{it}</w:p>" }.join}</w:body></w:document>) }
end

doc = Docx::Document.open("repro.docx")
doc.paragraphs.each do |paragraph|
  before = paragraph.text
  paragraph.substitute("{{name}}", "Jane")
  puts "#{before.inspect} => #{paragraph.text.inspect}"
end
doc.save("repro_out.docx")
puts Docx::Document.open("repro_out.docx").doc.xpath("//w:t", "w" => W).to_a.last(3).map(&:to_xml)