* test/-ext-/string/test_modify_expand.rb: test for r34492.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34493 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/-ext-/string/test_modify_expand.rb

@@ -0,0 +1,29 @@
+require 'test/unit'
+require "-test-/string/string"
+require_relative '../../ruby/envutil'
+
+class Test_StringModifyExpand < Test::Unit::TestCase
+  def test_modify_expand_memory_leak
+    before = after = nil
+    args = [
+      "--disable=gems", "-r-test-/string/string",
+      "-I"+File.expand_path("../../..", __FILE__),
+      "-rruby/memory_status",
+      "-e", <<-CMD
+      s=Bug::String.new
+      size=Memory::Status.new.size
+      puts size
+      10.times{s.modify_expand!(size)}
+      s.replace("")
+      puts Memory::Status.new.size
+    CMD
+    ]
+    status = EnvUtil.invoke_ruby(args, "", true) do |in_p, out_p, err_p, pid|
+      before, after = out_p.readlines.map(&:to_i)
+      Process.wait(pid)
+      $?
+    end
+    assert_equal(true, status.success?)
+    assert_operator after.fdiv(before), :<, 2
+  end
+end