Bug #3203 - Fix for download plans docx being malformed if it has

character combinations lik \0.. or \F.., e,g, as in
 G:\Hematologie\Onderzoek\Studie Team Hematologie\Studies op alfabet\studies\abc\00. DIGITAAL ISF\03. Contracts - Agreements\a. Clinical Trial Agreement.

Fix for issue #3203.

Change:
The htmltoword gem converts html to docx, so we clean the html string by
replacing single backslashes \ by double backslashes \\.

Author: John Pinto

app/controllers/plan_exports_controller.rb

@@ -78,8 +78,8 @@ def show_text
   def show_docx
     # Using and optional locals_assign export_format
     render docx: "#{file_name}.docx",
-           content: render_to_string(partial: 'shared/export/plan',
-                                     locals: { export_format: 'docx' })
+           content: clean_html_for_docx_creation(render_to_string(partial: 'shared/export/plan',
+                                                                  locals: { export_format: 'docx' }))
   end
 
   def show_pdf
@@ -136,4 +136,11 @@ def export_params
                   :custom_sections, :research_outputs,
                   formatting: [:font_face, :font_size, { margin: %i[top right bottom left] }])
   end
+
+  # A method to deal with problematic text combinations
+  # in html that break docx creation by htmltoword gem.
+  def clean_html_for_docx_creation(html)
+    # Replaces single backslash \ with \\ with gsub.
+    html.gsub(/\\/, '\&\&')
+  end
 end