erb.rb: safe concurrent use

* lib/erb.rb (ERB#run, ERB#result): eval under isolated bindings for
  safe concurrent use.  [ruby-core:47638] [Bug #7046]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37594 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 9 insertions, 2 deletions

diff --git a/lib/erb.rb b/lib/erb.rb
index 26c34ee3ad..934d83aa48 100644
--- a/lib/erb.rb
+++ b/lib/erb.rb
@@ -1,3 +1,4 @@
+# -*- coding: us-ascii -*-
 # = ERB -- Ruby Templating
 #
 # Author:: Masatoshi SEKI
@@ -818,7 +819,7 @@ class ERB
   end
 
   # Generate results and print them. (see ERB#result)
-  def run(b=TOPLEVEL_BINDING)
+  def run(b=new_toplevel)
     print self.result(b)
   end
 
@@ -830,7 +831,7 @@ class ERB
   # _b_ accepts a Binding or Proc object which is used to set the context of
   # code evaluation.
   #
-  def result(b=TOPLEVEL_BINDING)
+  def result(b=new_toplevel)
     if @safe_level
       proc {
         $SAFE = @safe_level
@@ -841,6 +842,12 @@ class ERB
     end
   end
 
+  def new_toplevel
+    # New binding each time *near* toplevel for unspecified runs
+    TOPLEVEL_BINDING.dup
+  end
+  private :new_toplevel
+
   # Define _methodname_ as instance method of _mod_ from compiled ruby source.
   #
   # example: