Ensure leading slashes in path matching.

lib/jekyll/core_ext.rb

@@ -55,9 +55,19 @@ class Hash
 end
 
 module Enumerable
+  def ensure_leading_slash(path)
+    path[0..0] == "/" ? path : "/#{path}"
+  end
+
   # Returns true if path matches against any glob pattern.
   # Look for more detail about glob pattern in method File::fnmatch.
   def glob_include?(e)
-    any? { |exp| File.fnmatch?(exp, e) }
+    entry = ensure_leading_slash(e)
+    any? do |exp|
+      item = ensure_leading_slash(exp)
+      Jekyll.logger.debug "glob_include?(#{entry})"
+      Jekyll.logger.debug "    ==> File.fnmatch?(#{item}, #{entry}) == #{File.fnmatch?(item, entry)}"
+      File.fnmatch?(item, entry)
+    end
   end
 end