Backport 37ed86fd3c798e298fad9db6e7df1f3f45e1e03b (#10248)

merge revision(s) 37ed86fd3c798e298fad9db6e7df1f3f45e1e03b: [Backport #--ticket=20161]

	Fix memory leak in regexp grapheme clusters

	[Bug #20161]

	The cc->mbuf gets overwritten, so we need to free it to not leak memory.

	For example:

	    str = "hello world".encode(Encoding::UTF_32LE)

	    10.times do
	      1_000.times do
	        str.grapheme_clusters
	      end

	      puts `ps -o rss= -p #{$$}`
	    end

	Before:

	    15536
	    15760
	    15920
	    16144
	    16304
	    16480
	    16640
	    16784
	    17008
	    17280

	After:

	    15584
	    15584
	    15760
	    15824
	    15888
	    15888
	    15888
	    15888
	    16048
	    16112
	---
	 regparse.c | 3 ++-
	 1 file changed, 2 insertions(+), 1 deletion(-)

2 files changed, 3 insertions, 2 deletions

diff --git a/regparse.c b/regparse.c
index 1ce15da8f5..57ecd78dee 100644
--- a/regparse.c
+++ b/regparse.c
@@ -6105,7 +6105,8 @@ node_extended_grapheme_cluster(Node** np, ScanEnv* env)
           R_ERR(add_code_range(&(cc->mbuf), env, 0x000A, 0x000A)); /* CR */
           R_ERR(add_code_range(&(cc->mbuf), env, 0x000D, 0x000D)); /* LF */
           R_ERR(not_code_range_buf(env->enc, cc->mbuf, &inverted_buf, env));
-          cc->mbuf = inverted_buf; /* TODO: check what to do with buffer before inversion */
+          bbuf_free(cc->mbuf);
+          cc->mbuf = inverted_buf;
 
           env->warnings_flag &= dup_not_warned; /* TODO: fix false warning */
         }
diff --git a/version.h b/version.h
index 39717974d2..bdeb9f6ab6 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 0
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 12
+#define RUBY_PATCHLEVEL 13
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"