merge revision(s) 54c4694994cc3bcfea9058b22ba3e68af6aaf740: [Backport #21961]

	[PATCH] marshal.c: properly freeze linked strings

	[Bug #21961]

3 files changed, 18 insertions, 1 deletions

diff --git a/marshal.c b/marshal.c
index fca246664e..4538249307 100644
--- a/marshal.c
+++ b/marshal.c
@@ -1880,6 +1880,9 @@ r_object_for(struct load_arg *arg, bool partial, int *ivp, VALUE extmod, int typ
         }
         v = (VALUE)link;
         if (!st_lookup(arg->partial_objects, (st_data_t)v, &link)) {
+            if (arg->freeze && RB_TYPE_P(v, T_STRING)) {
+                v = rb_str_to_interned_str(v);
+            }
             v = r_post_proc(v, arg);
         }
         break;
diff --git a/test/ruby/test_marshal.rb b/test/ruby/test_marshal.rb
index 2c5985f1d7..4d26eb3a76 100644
--- a/test/ruby/test_marshal.rb
+++ b/test/ruby/test_marshal.rb
@@ -971,5 +971,19 @@ class TestMarshal < Test::Unit::TestCase
       refute_predicate Object, :frozen?
       refute_predicate Kernel, :frozen?
     end
+
+    def test_linked_strings_are_frozen
+      str = "test"
+      str.instance_variable_set(:@self, str)
+      source = [str, str]
+
+      objects = Marshal.load(encode(source), freeze: true)
+      assert_predicate objects[0], :frozen?
+      assert_predicate objects[1], :frozen?
+      assert_same objects[0], objects[1]
+      assert_same objects[0], objects[0].instance_variable_get(:@self)
+      assert_same objects[1], objects[1].instance_variable_get(:@self)
+      assert_same objects[0].instance_variable_get(:@self), objects[1].instance_variable_get(:@self)
+    end
   end
 end
diff --git a/version.h b/version.h
index 627e065c3b..71a6c68213 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 10
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 203
+#define RUBY_PATCHLEVEL 204
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"