Exclude '_' and '-' from PN_LOCAL escapes. Not all reserved characters need to be escaped in SPARQL/Turtle, but they must be unescaped when encountered.

Author: gkellogg

lib/rdf/model/uri.rb

@@ -112,8 +112,9 @@ class URI
     ).freeze
 
     # Characters in a PName which must be escaped
-    PN_ESCAPE_CHARS      = /[~\.\-!\$&'\(\)\*\+,;=\/\?\#@%_]/.freeze
-    PN_ESCAPES           = /\\#{PN_ESCAPE_CHARS}/.freeze
+    # Note: not all reserved characters need to be escaped in SPARQL/Turtle, but they must be unescaped when encountered
+    PN_ESCAPE_CHARS      = /[~\.!\$&'\(\)\*\+,;=\/\?\#@%]/.freeze
+    PN_ESCAPES           = /\\#{Regexp.union(PN_ESCAPE_CHARS, /[\-_]/)}/.freeze
 
     ##
     # Cache size may be set through {RDF.config} using `uri_cache_size`.

lib/rdf/vocabulary.rb

@@ -389,7 +389,7 @@ def expand_pname(pname)
         return pname unless pname.is_a?(String) || pname.is_a?(Symbol)
         prefix, suffix = pname.to_s.split(":", 2)
         # Unescape escaped PN_ESCAPE_CHARS
-        if suffix.match?(/\\#{RDF::URI::PN_ESCAPE_CHARS}/)
+        if suffix.match?(RDF::URI::PN_ESCAPES)
           suffix = suffix.gsub(RDF::URI::PN_ESCAPES) {|matched| matched[1..-1]}
         end
         if prefix == "rdf"

spec/model_uri_spec.rb

@@ -890,7 +890,6 @@
 
     context "escapes" do
       {
-        "http://example.org/c-" => 'ex:c\-',
         "http://example.org/c!" => 'ex:c\!',
         "http://example.org/c$" => 'ex:c\$',
         "http://example.org/c&" => 'ex:c\&',
@@ -899,7 +898,7 @@
         "http://example.org/c*+" => 'ex:c\*\+',
         "http://example.org/c;=" => 'ex:c\;\=',
         "http://example.org/c/#" => 'ex:c\/\#',
-        "http://example.org/c@_" => 'ex:c\@\_',
+        "http://example.org/c@" => 'ex:c\@',
         "http://example.org/c:d?" => 'ex:c:d\?',
         "http://example.org/c~z." => 'ex:c\~z\.',
       }.each do |orig, result|
@@ -910,6 +909,18 @@
           expect(pname).to eql result
         end
       end
+
+      {
+        "http://example.org/c-" => 'ex:c\-',
+        "http://example.org/c_" => 'ex:c\_',
+      }.each do |orig, result|
+        it "does not #{orig} => #{result}" do
+          uri = RDF::URI(orig)
+          pname = uri.pname(prefixes: {ex: "http://example.org/"})
+          expect(uri).to be_valid
+          expect(pname).not_to eql result
+        end
+      end
     end
   end