Make use of the pcre2_maketables_free() function to free the memory
allocated by pcre2_maketables(). At first sight it's strange that
10da030ab75 (grep: avoid leak of chartables in PCRE2, 2019-10-16)
which added the free() call here doesn't make use of the pcre2_free()
the author introduced in the preceding commit in 513f2b0bbd4 (grep:
make PCRE2 aware of custom allocator, 2019-10-16).

The reason is that at the time the function didn't exist. It was first
introduced in PCREv2 version 10.34, released on 2019-11-21.

Let's make use of it behind a macro. I don't think this matters for
anything to do with custom allocators, but it makes our use of PCREv2
more discoverable. At some distant point in the future we'll be able
to drop the version guard, as nobody will be running a version older
than 10.34.

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---
 grep.c | 4 ++++
 grep.h | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/grep.c b/grep.c
index e58044474d..c63dbff4b2 100644
--- a/grep.c
+++ b/grep.c

@@ -490,7 +490,11 @@ static void free_pcre2_pattern(struct grep_pat *p)
 	pcre2_compile_context_free(p->pcre2_compile_context);
 	pcre2_code_free(p->pcre2_pattern);
 	pcre2_match_data_free(p->pcre2_match_data);
+#ifdef GIT_PCRE2_VERSION_10_34_OR_HIGHER
+	pcre2_maketables_free(pcre2_global_context, p->pcre2_tables);
+#else
 	free((void *)p->pcre2_tables);
+#endif
 }
 #else /* !USE_LIBPCRE2 */
 static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt)

diff --git a/grep.h b/grep.h
index 54e52042cb..64666e9204 100644
--- a/grep.h
+++ b/grep.h

@@ -7,6 +7,9 @@
 #if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 36) || PCRE2_MAJOR >= 11
 #define GIT_PCRE2_VERSION_10_36_OR_HIGHER
 #endif
+#if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 34) || PCRE2_MAJOR >= 11
+#define GIT_PCRE2_VERSION_10_34_OR_HIGHER
+#endif
 #else
 typedef int pcre2_code;
 typedef int pcre2_match_data;

-- 
2.30.0.284.gd98b1dd5eaa7