Support non-recursive dump_headline.

org_rw/org_rw.py

@@ -102,6 +102,14 @@ NON_FINISHED_GROUPS = (type(None), dom.ListGroupNode, dom.ResultsDrawerNode, dom
 FREE_GROUPS = (dom.CodeBlock,)
 
 
+class NonReproducibleDocument(Exception):
+    """
+    Exception thrown when a document would be saved as different contents
+    from what it's loaded from.
+    """
+    pass
+
+
 def get_tokens(value):
     if isinstance(value, Text):
         return value.contents
@@ -1665,7 +1673,7 @@ class OrgDoc:
             yield from headline.get_code_snippets()
 
     # Writing
-    def dump_headline(self, headline):
+    def dump_headline(self, headline, recursive=True):
 
         tags = ""
         if len(headline.shallow_tags) > 0:
@@ -1738,8 +1746,9 @@ class OrgDoc:
             content = content[:-1]
             yield content
 
-        for child in headline.children:
-            yield from self.dump_headline(child)
+        if recursive:
+            for child in headline.children:
+                yield from self.dump_headline(child, recursive=recursive)
 
     def dump(self):
         lines = []
@@ -2008,7 +2017,7 @@ def loads(s, environment=BASE_ENVIRONMENT, extra_cautious=True):
                         context_last_line = None
             # print("---\n" + after_dump + "\n---")
 
-            raise Exception("Difference found between existing version and dumped")
+            raise NonReproducibleDocument("Difference found between existing version and dumped")
     return doc