1 files changed, 34 insertions, 3 deletions
diff --git a/test/ruby/test_weakmap.rb b/test/ruby/test_weakmap.rb
index 0371afa77a..4f5823ecf4 100644
--- a/test/ruby/test_weakmap.rb
+++ b/test/ruby/test_weakmap.rb
@@ -78,7 +78,7 @@ class TestWeakMap < Test::Unit::TestCase
       @wm[i] = Object.new
       @wm.inspect
     end
-    assert_match(/\A\#<#{@wm.class.name}:[^:]++:(?:\s\d+\s=>\s\#<(?:Object|collected):[^:<>]*+>(?:,|>\z))+/,
+    assert_match(/\A\#<#{@wm.class.name}:0x[\da-f]+(?::(?: \d+ => \#<(?:Object|collected):0x[\da-f]+>,?)+)?>\z/,
                  @wm.inspect)
   end
 
@@ -203,7 +203,7 @@ class TestWeakMap < Test::Unit::TestCase
       @wm[i] = obj
     end
 
-    assert_separately([], <<-'end;')
+    assert_ruby_status([], <<-'end;')
       wm = ObjectSpace::WeakMap.new
       obj = Object.new
       100.times do
@@ -224,7 +224,7 @@ class TestWeakMap < Test::Unit::TestCase
       assert_equal(val, wm[key])
     end;
 
-    assert_separately(["-W0"], <<-'end;')
+    assert_ruby_status(["-W0"], <<-'end;')
       wm = ObjectSpace::WeakMap.new
 
       ary = 10_000.times.map do
@@ -238,6 +238,7 @@ class TestWeakMap < Test::Unit::TestCase
   end
 
   def test_gc_compact_stress
+    omit "compaction doesn't work well on s390x" if RUBY_PLATFORM =~ /s390x/ # https://github.com/ruby/ruby/pull/5077
     EnvUtil.under_gc_compact_stress { ObjectSpace::WeakMap.new }
   end
 
@@ -257,4 +258,34 @@ class TestWeakMap < Test::Unit::TestCase
 
     assert_equal b, @wm[1]
   end
+
+  def test_use_after_free_bug_20688
+    assert_normal_exit(<<~RUBY)
+      weakmap = ObjectSpace::WeakMap.new
+      10_000.times { weakmap[Object.new] = Object.new }
+    RUBY
+  end
+
+  def test_generational_gc
+    EnvUtil.without_gc do
+      wmap = ObjectSpace::WeakMap.new
+
+      (GC::INTERNAL_CONSTANTS[:RVALUE_OLD_AGE] - 1).times { GC.start }
+
+      retain = []
+      50.times do
+        k = Object.new
+        wmap[k] = true
+        retain << k
+      end
+
+      GC.start # WeakMap promoted, other objects still young
+
+      retain.clear
+
+      GC.start(full_mark: false)
+
+      wmap.keys.each(&:itself) # call method on keys to cause crash
+    end
+  end
 end