Avoid line offset correction, as it's tricky to do it correctly.

Note that we might want to restore the offset correction at some point to allow looking at the line positions after the
    load is completed.

org_rw/org_rw.py

@@ -820,17 +820,6 @@ class Headline:
             raise NotImplementedError()
 
     def update_raw_contents(self, new_contents):
-        # Clear elements
-        self.keywords = []
-        self.contents = []
-        self.list_items = []
-        self.table_rows = []
-        self.properties = []
-        self.structural = []
-        self.delimiters = []
-        self.scheduled = None
-        self.deadline = None
-        self.closed = None
 
         reader = OrgDocReader(environment=self.doc.environment)
         reader.read(new_contents)
@@ -840,20 +829,19 @@ class Headline:
             # Probably can be done by just adding the headlines to this one's children
             raise NotImplementedError('new headlines on raw contents not supported yet. This probably should be simple, see comment on code.')
 
-        for kw in reader.keywords:
-            self.keywords.append(offset_linenum(self.start_line + 1, kw))
+        # Clear elements
+        self.keywords = reader.keywords
+        self.contents = reader.contents
+        self.list_items = reader.list_items
+        self.table_rows = reader.table_rows
+        self.properties = reader.properties
+        self.structural = reader.structural
+        self.delimiters = reader.delimiters
 
-        for content in reader.contents:
-            self.contents.append(offset_linenum(self.start_line + 1, content))
-
-        for list_item in reader.list_items:
-            self.list_items.append(offset_linenum(self.start_line + 1, list_item))
-
-        for struct_item in reader.structural:
-            self.structural.append(offset_linenum(self.start_line + 1, struct_item))
-
-        for prop in reader.properties:
-            self.properties.append(offset_linenum(self.start_line + 1, prop))
+        # TODO: Support update of scheduled/deadline/closed line
+        self.scheduled = None
+        self.deadline = None
+        self.closed = None
 
         # Environment is not used, as it's known
 
@@ -1074,20 +1062,6 @@ TableRow = collections.namedtuple(
     ),
 )
 
-ItemWithLineNum = Union[Keyword, RawLine, Property, ListItem, tuple[int, Any]]
-def offset_linenum(offset: int, item: ItemWithLineNum) -> ItemWithLineNum:
-    if isinstance(item, tuple) and len(item) == 2 and isinstance(item[0], int):
-        return item
-
-    if isinstance(item, ListItem):
-        item.linenum += offset
-        return item
-
-    assert isinstance(item, (Keyword, RawLine, Property)), \
-        "Expected (Keyword|RawLine|Property), found {}".format(item)
-    return item._replace(linenum=item.linenum + offset)
-
-
 # @TODO How are [YYYY-MM-DD HH:mm--HH:mm] and ([... HH:mm]--[... HH:mm]) differentiated ?
 # @TODO Consider recurrence annotations
 class Timestamp: