book: redirect missing xrefs to the English book

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

script/book.rb

@@ -164,8 +164,12 @@ def save
     FileUtils.mkdir_p(self.absolute_path("ch00"))
     @xrefs.each do |id_xref, section|
       path = self.absolute_path("ch00/#{id_xref}.html")
-      relurl = "#{section.relative_url(nil)}##{id_xref}"
-      front_matter = { "redirect_to" => relurl }
+      if section == 'redirect-to-en'
+        url = "book/en/v2/ch00/#{id_xref}"
+      else
+        url = "#{section.relative_url(nil)}##{id_xref}"
+      end
+      front_matter = { "redirect_to" => url }
       File.open(path, 'w') do |file|
         file.write(self.wrap_front_matter(front_matter))
       end

script/update-book2.rb

@@ -134,6 +134,7 @@ def genbook(language_code, &get_content)
       xlink = html.scan(/href="1-.*?\.html\#(.*?)"/)
       xlink&.each do |link|
         xref = link.first
+	book.xrefs[xref] = 'redirect-to-en' if !book.xrefs[xref]
         begin
           html.gsub!(/href="1-.*?\.html\##{xref}"/, "href=\"{{< relurl \"#{book_prefix}ch00/#{xref}\" >}}\"")
         rescue StandardError
@@ -144,6 +145,7 @@ def genbook(language_code, &get_content)
       xlink = html.scan(/href="\#(.*?)"/)
       xlink&.each do |link|
         xref = link.first
+	book.xrefs[xref] = 'redirect-to-en' if !book.xrefs[xref]
         begin
           html.gsub!(/href="\##{xref}"/, "href=\"{{< relurl \"#{book_prefix}ch00/#{xref}\" >}}\"")
         rescue StandardError