[Truffle] Add modification check to String#sub!

jruby · Jun 29, 2016 · 7523d6f · 7523d6f
1 parent 2883eb6
commit 7523d6f
Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/spec/truffle/tags/core/string/sub_tags.txt b/spec/truffle/tags/core/string/sub_tags.txt
diff --git a/truffle/src/main/ruby/core/string.rb b/truffle/src/main/ruby/core/string.rb
@@ -847,11 +847,15 @@ def sub!(pattern, replacement=undefined)
       if use_yield || hash
         Regexp.last_match = match
 
+        duped = dup
         if use_yield
           val = yield match.to_s
         else
           val = hash[match.to_s]
         end
+        if duped != self
+          raise RuntimeError, "string modified"
+        end
         untrusted = true if val.untrusted?
         val = val.to_s unless val.kind_of?(String)