Update to nanoc4.

Signed-off-by: Thomas Hochstein <thh@inter.net>

README.md

@@ -1,14 +1,14 @@
 # nanoc extensions
 
-*[nanoc](http://nanoc.ws/)* is a popular *static site generator*.
+*[Nanoc](http://nanoc.ws/)* is a popular *static site generator*.
 
-I'll add some little extensions for *nanoc* (v3) here.
+I'll add some little extensions for *Nanoc* here.
 
 ## filters
 
 ### abbreviations.rb
 
-Simple *nanoc* filter to add `<abbr>` tags.
+Simple *Nanoc* filter to add `<abbr>` tags.
 
 After reading a YAML document from `/content/_data/abbreviations.yam`,
 all occurences of each $abbrev are replaced by a
@@ -37,7 +37,7 @@ from being rendered and compiled, i.e. like this:
 
 ### dejure.rb
 
-*nanoc* filter implementation of the *dejure.org*
+*Nanoc* filter implementation of the *dejure.org*
 [legal integration service](https://dejure.org/vernetzung.html).
 
     filter :dejure,

_doc/dejure/CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Version 1.2 (unreleased)
 
 * Create links with `https` protocol.
+* Nanoc 4.x compatibility
 
 ### Version 1.1 (2017-05-27)
 

lib/filters/dejure.rb

@@ -46,11 +46,13 @@ module Nanoc::Filters
     CACHEDIR  = 'tmp/dejure-org'
     CACHEDAYS = 7
 
-    def run(input, params={})
+    def run(input, filterparams={})
       # return input if there's nothing to replace
       return input if !(/§|§|Art\.|\/[0-9][0-9](?![0-9\/])| [0-9][0-9]?[\/\.][0-9][0-9](?![0-9\.])|[0-9][0-9], / =~ input)
       # return input if it contains '<!-- no-dejure -->'
       return input if (/<!-- ?no-?dejure ?-->/ =~ input)
+      # copy params (which are now immutable)
+      params = filterparams.dup
       # set cache validity in days from params or set a default
       cache_days = params.delete(:cache_days)
       cache_days = CACHEDAYS if cache_days.nil?