merge revision(s) 0b8f15575a440f85ac686f5b0eae8f8b7c2b72e7: [Backport #19836]

	Fix memory leak for incomplete lambdas

	[Bug #19836]

	The parser does not free the chain of `struct vtable`, which causes
	memory leaks.

	The following script reproduces this issue:

	```
	10.times do
	  100_000.times do
	    Ripper.parse("-> {")
	  end

	  puts `ps -o rss= -p #{$$}`
	end
	```
	---
	 parse.y                    | 24 ++++++++++++++----------
	 test/ripper/test_ripper.rb |  7 +++++++
	 2 files changed, 21 insertions(+), 10 deletions(-)

3 files changed, 37 insertions, 18 deletions

diff --git a/parse.y b/parse.y
index 221b6b7271..9dd56c0af1 100644
--- a/parse.y
+++ b/parse.y
@@ -13176,22 +13176,26 @@ local_push(struct parser_params *p, int toplevel_scope)
 }
 
 static void
-local_free(struct parser_params *p, struct local_vars *local)
+vtable_chain_free(struct parser_params *p, struct vtable *table)
 {
-    if (local->used) {
-        vtable_free(local->used);
+    while (!DVARS_TERMINAL_P(table)) {
+        struct vtable *cur_table = table;
+        table = cur_table->prev;
+        vtable_free(cur_table);
     }
+}
+
+static void
+local_free(struct parser_params *p, struct local_vars *local)
+{
+    vtable_chain_free(p, local->used);
 
 # if WARN_PAST_SCOPE
-    while (local->past) {
-        struct vtable *past = local->past;
-        local->past = past->prev;
-        vtable_free(past);
-    }
+    vtable_chain_free(p, local->past);
 # endif
 
-    vtable_free(local->args);
-    vtable_free(local->vars);
+    vtable_chain_free(p, local->args);
+    vtable_chain_free(p, local->vars);
 
     ruby_sized_xfree(local, sizeof(struct local_vars));
 }
diff --git a/test/ripper/test_ripper.rb b/test/ripper/test_ripper.rb
index a9773a89d8..83b43d67fe 100644
--- a/test/ripper/test_ripper.rb
+++ b/test/ripper/test_ripper.rb
@@ -120,13 +120,6 @@ class TestRipper::Ripper < Test::Unit::TestCase
       END
       assert_nil(Ripper.sexp(src), bug12651)
     end;
-
-    # [Bug #19835]
-    assert_no_memory_leak(%w(-rripper), "", "#{<<~'end;'}", rss: true)
-      1_000_000.times do
-        Ripper.parse("class Foo")
-      end
-    end;
   end
 
   # https://bugs.jruby.org/4176
@@ -148,6 +141,28 @@ end
     assert_nothing_raised { Ripper.lex src }
   end
 
+  def test_no_memory_leak
+    assert_no_memory_leak(%w(-rripper), "", "#{<<~'end;'}", rss: true)
+      2_000_000.times do
+        Ripper.parse("")
+      end
+    end;
+
+    # [Bug #19835]
+    assert_no_memory_leak(%w(-rripper), "", "#{<<~'end;'}", rss: true)
+      1_000_000.times do
+        Ripper.parse("class Foo")
+      end
+    end;
+
+    # [Bug #19836]
+    assert_no_memory_leak(%w(-rripper), "", "#{<<~'end;'}", rss: true)
+      1_000_000.times do
+        Ripper.parse("-> {")
+      end
+    end;
+  end
+
   class TestInput < self
     Input = Struct.new(:lines) do
       def gets
diff --git a/version.h b/version.h
index 875f6a20db..8235f15c3e 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 2
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 112
+#define RUBY_PATCHLEVEL 113
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"