Issue 2936 - Support syntax for duplicate translatable strings

cms/converters.py

Index: cms/converters.py
diff --git a/cms/converters.py b/cms/converters.py
index afa4ee4f31ef51cf1d39ffa7453154a5b51a2f9e..9d6b484f77f7b21e54e00615460817bc6f87d53b 100644
--- a/cms/converters.py
+++ b/cms/converters.py
@@ -117,6 +117,7 @@ class Converter:
     self._params = params
     self._key = key
     self._attribute_parser = AttributeParser(self.whitelist)
+    self._seen_defaults  = {}
 
     # Read in any parameters specified at the beginning of the file
     lines = params[key].splitlines(True)
@@ -133,6 +134,16 @@ class Converter:
     def re_escape(s):
       return re.escape(escape(s))
 
+    # Handle duplicated strings
+    if default:
+      self._seen_defaults[(page, name)] = default
+    else:
+      try:
+        default = self._seen_defaults[(page, name)]
+      except KeyError:
+        raise Exception("Text not yet defined for string %s on page %s" %
+                        (name, page))
+
     # Extract tag attributes from default string
     default, saved_attributes, fixed_strings = self._attribute_parser.parse(default, self._params["page"])
 
@@ -147,11 +158,12 @@ class Converter:
       self.missing_translations += 1
     self.total_translations += 1
 
-    # Perform callback with the string if required, e.g. for the translations script
-    callback = self._params["localized_string_callback"]
-    if callback:
-      callback(page, locale, name, result, comment, fixed_strings)
-
+    if default:
+      # Perform callback with the string if required,
+      # e.g. for the translations script
+      callback = self._params["localized_string_callback"]
+      if callback:
+        callback(page, locale, name, result, comment, fixed_strings)
 
     # Insert fixed strings
     for i, fixed_string in enumerate(fixed_strings, 1):
@@ -189,19 +201,20 @@ class Converter:
   def insert_localized_strings(self, text, escapes, to_html=lambda s: s):
     def lookup_string(match):
       name, comment, default = match.groups()
-      default = to_html(default).strip()
-
+      if default:
+        default = to_html(default).strip()
       return self.localize_string(self._params["page"], name, default,
                                   comment, self._params["localedata"], escapes)
 
     return re.sub(
       r"{{\s*"
       r"([\w\-]+)" # String ID
-      r"(?:\[(.*?)\])?" # Optional comment
-      r"\s+"
-      r"((?:(?!{{).|" # Translatable text
-        r"{{(?:(?!}}).)*}}" # Nested translation
-      r")*?)"
+      r"(?:(?:\[(.*?)\])?" # Optional comment
+        r"\s+"
+        r"((?:(?!{{).|" # Translatable text
+          r"{{(?:(?!}}).)*}}" # Nested translation
+        r")*?)"
+      r")?"
       r"}}",
       lookup_string,
       text,