Skip to content

RuntimeError "entity expansion has grown too large" with default entities in REXML::Parsers::BaseParser after 3.3.3 #198

Closed
@vikiv480

Description

Why?

We are using the ruby/rss gem to parse XML feeds and we get RuntimeErrors “entity expansion has grown too large” since rexml 3.3.3 even though there is only default entities in the feeds.

How to reproduce

Code:

# rexml/refactor_entity_example.rb

$LOAD_PATH.unshift(File.expand_path("lib"))

require "rexml/parsers/baseparser"

valid_feed = "<p>#{'A' * 10_240}</p>"

base_parser = REXML::Parsers::BaseParser.new("")
base_parser.unnormalize(valid_feed) # => "<p>" + "A" * 10_240 + "</p>"

Error:

❯ bundle exec ruby refactor_entity_example.rb
/Users/vikiv/repos/rexml/lib/rexml/parsers/baseparser.rb:558:in `block in unnormalize': entity expansion has grown too large (RuntimeError)
	from /Users/vikiv/repos/rexml/lib/rexml/parsers/baseparser.rb:551:in `each'
	from /Users/vikiv/repos/rexml/lib/rexml/parsers/baseparser.rb:551:in `unnormalize'
	from refactor_entity_example.rb:8:in `<main>'

Suggestion



I suggest we change #entity/#unnormalize to not raise the RuntimeError “entity expansion has grown too large” when the feed consists of only default entities.

diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index 342f948..d560d3a 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -505,15 +505,13 @@ module REXML
       private :pull_event

       def entity( reference, entities )
-        value = nil
         value = entities[ reference ] if entities
         if value
           record_entity_expansion
-        else
-          value = DEFAULT_ENTITIES[ reference ]
-          value = value[2] if value
+          return unnormalize( value, entities ) if value
         end
-        unnormalize( value, entities ) if value
+
+        nil
       end

       # Escapes all possible entities

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions