lib/kramdown/parser/kramdown/header.rb in kramdown-0.9.0 vs lib/kramdown/parser/kramdown/header.rb in kramdown-0.10.0

@@ -22,10 +22,10 @@
 
 module Kramdown
   module Parser
     class Kramdown
 
-      HEADER_ID=/(?:[ \t]\{#((?:\w|\d)[\w\d-]*)\})?/
+      HEADER_ID=/(?:[ \t]\{#(\w[\w-]*)\})?/
       SETEXT_HEADER_START = /^(#{OPT_SPACE}[^ \t].*?)#{HEADER_ID}[ \t]*?\n(-|=)+\s*?\n/
 
       # Parse the Setext header at the current location.
       def parse_setext_header
         if @tree.children.last && @tree.children.last.type != :blank