po parser: fix a too much unescape bug

Author: kou

src/po_parser.ry

@@ -24,7 +24,7 @@ class GetText::POParser
   msgctxt
   : MSGCTXT string_list
   {
-    @msgctxt = unescape(val[1])
+    @msgctxt = val[1]
   }
   ;
 
@@ -36,9 +36,8 @@ class GetText::POParser
   single_message
   : MSGID string_list MSGSTR string_list
   {
-    msgid_raw = val[1]
-    msgid = unescape(msgid_raw)
-    msgstr = unescape(val[3])
+    msgid = val[1]
+    msgstr = val[3]
     use_message_p = true
     if @fuzzy and not msgid.empty?
       use_message_p = (not ignore_fuzzy?)
@@ -48,7 +47,7 @@ class GetText::POParser
         else
           $stderr.print _("Warning: fuzzy message was used.\n")
         end
-        $stderr.print "  #{@po_file}: msgid '#{msgid_raw}'\n"
+        $stderr.print "  #{@po_file}: msgid '#{msgid}'\n"
       end
     end
     @fuzzy = false
@@ -144,20 +143,23 @@ require "gettext/po"
     @report_warning
   end
 
-  def unescape(orig)
-    ret = orig.gsub(/\\n/, "\n")
-    ret.gsub!(/\\t/, "\t")
-    ret.gsub!(/\\r/, "\r")
-    ret.gsub!(/\\"/, "\"")
-    ret
+  def unescape(string)
+    string.gsub(/\\(.)/) do
+      escaped_character = $1
+      case escaped_character
+      when "t"
+        "\t"
+      when "r"
+        "\r"
+      when "n"
+        "\n"
+      else
+        escaped_character
+      end
+    end
   end
   private :unescape
 
-  def unescape_string(string)
-    string.gsub(/\\\\/, "\\")
-  end
-  private :unescape_string
-
   def parse(str, data)
     @translator_comments = []
     @extracted_comments = []
@@ -202,7 +204,7 @@ require "gettext/po"
         @q.push [:COMMENT, $&]
         str = $'
       when /\A\"(.*)\"/
-        @q.push [:STRING, unescape_string($1)]
+        @q.push [:STRING, unescape($1)]
         str = $'
       else
         #c = str[0,1]

test/test_po_parser.rb

@@ -62,6 +62,16 @@ def test_plural
   class TestPO < self
     include Helper::Warning
 
+    def test_msgid_escape
+      po_file = create_po_file(<<-'EOP')
+msgid "\\\\r \\r \t \r \n"
+msgstr "\\\\r \\r \t \r \n"
+EOP
+      entries = parse_po_file(po_file)
+      assert_equal("\\\\r \\r \t \r \n",
+                   entries["\\\\r \\r \t \r \n"].msgstr)
+    end
+
     def test_msgstr
       po_file = create_po_file(<<-EOP)
 # This is the comment.