Index: translate/storage/cpo.py
===================================================================
--- translate/storage/cpo.py	(revision 8068)
+++ translate/storage/cpo.py	(working copy)
@@ -140,6 +140,7 @@
 gpo.po_message_set_extracted_comments.argtypes = [c_int, STRING]
 gpo.po_message_set_fuzzy.argtypes = [c_int, c_int]
 gpo.po_message_set_msgctxt.argtypes = [c_int, STRING]
+gpo.po_message_set_format.argtypese = [c_int, STRING, c_int]
 
 # Setup the po_xerror_handler
 xerror_handler = po_xerror_handler()
@@ -371,9 +372,34 @@
         gpo.po_message_set_comments(self._gpo_message, "")
 
     def copy(self):
-        newpo = self.__class__()
-        newpo._gpo_message = self._gpo_message
-        return newpo
+        """Returns a copy of the this unit that can be used independently.
+        """
+        unit = pounit()
+        unit.source = self.source
+        unit.target = self.target
+        unit.markfuzzy(self.isfuzzy())
+        if self.isobsolete():
+            unit.makeobsolete()
+        for location in self.getlocations():
+            unit.addlocation(location)
+        notes = []
+        origins = ['translator', 'developer', 'programmer', 'source code']
+        for origin in origins:
+            note = self.getnotes(origin=origin)
+            if note in notes:
+                continue
+            else:
+                unit.addnote(note, origin=origin)
+                notes.append(note)
+        context = gpo.po_message_msgctxt(self._gpo_message)
+        if context:
+            unit.setcontext(context)
+        comments = self._extract_msgidcomments()
+        if comments:
+            unit.setmsgidcomment(comments)
+        for typecomment in self.gettypecomments():
+            unit.addtypecomment(typecomment)
+        return unit
 
     def merge(self, otherpo, overwrite=False, comments=True, authoritative=False):
         """Merges the otherpo (with the same msgid) into this one.
@@ -422,6 +448,32 @@
     def hastypecomment(self, typecomment):
         return gpo.po_message_is_format(self._gpo_message, typecomment)
 
+    def gettypecomments(self):
+        """Returns the type comments of a unit, if any.
+
+        @return: a list containing the type comments of the unit
+        """
+        #XXX: brute force
+        formats = [
+            "c", "objc", "sh", "python", "lisp", "elisp", "librep", "scheme",
+            "smalltalk", "java", "csharp", "awk", "object-pascal", "ycp", "tcl",
+            "perl", "perl-brace", "php", "gcc-internal", "qt", "kde", "boost",
+        ]
+        comments = []
+        for format in formats:
+            format += '-format'
+            if self.hastypecomment(format):
+                comments.append(format)
+        return comments
+
+    def addtypecomment(self, typecomment):
+        """Adds a type comment to the unit
+
+        @oaram typecomment: the type comment to be added, for example
+            "c-format".
+        """
+        gpo.po_message_set_format(self._gpo_message, typecomment, 1)
+
     def hasmarkedcomment(self, commentmarker):
         commentmarker = "(%s)" % commentmarker
         for comment in self.getnotes("translator").split("\n"):
@@ -476,7 +528,8 @@
 
     def __str__(self):
         pf = pofile()
-        pf.addunit(self)
+        unit = self.copy()
+        pf.addunit(unit)
         return str(pf)
 
     def getlocations(self):
@@ -505,6 +558,10 @@
                 line = -1
             gpo.po_message_add_filepos(self._gpo_message, file, line)
 
+    def setcontext(self, context):
+        """Sets the context message"""
+        gpo.po_message_set_msgctxt(self._gpo_message, context)
+
     def getcontext(self):
         msgctxt = gpo.po_message_msgctxt(self._gpo_message)
         msgidcomment = self._extract_msgidcomments()
@@ -528,9 +585,15 @@
             self._gpo_message_iterator = gpo.po_message_iterator(self._gpo_memory_file, None)
 
     def addunit(self, unit):
-        gpo.po_message_insert(self._gpo_message_iterator, unit._gpo_message)
-        self.units.append(unit)
+        unitcopy = unit.copy()
+        gpo.po_message_insert(self._gpo_message_iterator, unitcopy._gpo_message)
+        self.units.append(unitcopy)
 
+    def addsourceunit(self, source):
+        self.addunit(self.UnitClass(source))
+        unit = self.findunit(source)
+        return unit
+
     def removeduplicates(self, duplicatestyle="merge"):
         """make sure each msgid is unique ; merge comments etc from duplicates into original"""
         msgiddict = {}
@@ -600,6 +663,7 @@
                     while location:
                         gpo.po_message_remove_filepos(unit._gpo_message, 0)
                         location = gpo.po_message_filepos(unit._gpo_message, 0)
+
         outputstring = ""
         if self._gpo_memory_file:
             obsolete_workaround()
@@ -664,12 +728,10 @@
             newunit = pounit(gpo_message=newmessage)
             self.units.append(newunit)
             newmessage = gpo.po_next_message(self._gpo_message_iterator)
-        self._free_iterator()
 
     def __del__(self):
         # We currently disable this while we still get segmentation faults.
         # Note that this is definitely leaking memory because of this.
-        return
         self._free_iterator()
         if self._gpo_memory_file is not None:
             gpo.po_file_free(self._gpo_memory_file)
@@ -678,7 +740,6 @@
     def _free_iterator(self):
         # We currently disable this while we still get segmentation faults.
         # Note that this is definitely leaking memory because of this.
-        return
         if self._gpo_message_iterator is not None:
             gpo.po_message_iterator_free(self._gpo_message_iterator)
             self._gpo_message_iterator = None