https://bugs.gentoo.org/964425
https://github.com/PCRE2Project/pcre2/issues/831
https://github.com/PCRE2Project/pcre2/pull/835 (doc change snipped)

From 6454fac3920d9223a2b05becf15e3cb8e6022243 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlo=20Marcelo=20Arenas=20Bel=C3=B3n?= <carenas@gmail.com>
Date: Thu, 30 Oct 2025 13:57:32 -0700
Subject: [PATCH] pcre2test: dynamically allocate buffer for JITTARGET (#835)

Always ask `pcre2_config()` for the expected size of buffers and abort if
it is too small.

In the documentation, remove the description of a static buffer size for
JITTARGET.
---
 src/pcre2test.c     | 12 ++++++------
 src/pcre2test_inc.h | 35 ++++++++++++++++++++++++++---------
 3 files changed, 43 insertions(+), 25 deletions(-)

--- a/src/pcre2test.c
+++ b/src/pcre2test.c
@@ -2942,9 +2942,9 @@ static int pcre2_config(uint32_t what, void *where)
 DISPATCH(return, pcre2_config_, (what, where));
 }
 
-static void config_str(uint32_t what, char *where)
+static char *config_str(uint32_t what, char *where, int size)
 {
-DISPATCH(, config_str_, (what, where));
+DISPATCH(return, config_str_, (what, where, size));
 }
 
 static BOOL decode_modifiers(uint8_t *p, int ctx, patctl *pctl, datctl *dctl)
@@ -3014,7 +3014,7 @@ static void
 print_version(FILE *f, BOOL include_mode)
 {
 char buf[VERSION_SIZE];
-config_str(PCRE2_CONFIG_VERSION, buf);
+config_str(PCRE2_CONFIG_VERSION, buf, sizeof(buf));
 fprintf(f, "PCRE2 version %s", buf);
 if (include_mode)
   {
@@ -3033,7 +3033,7 @@ static void
 print_unicode_version(FILE *f)
 {
 char buf[VERSION_SIZE];
-config_str(PCRE2_CONFIG_UNICODE_VERSION, buf);
+config_str(PCRE2_CONFIG_UNICODE_VERSION, buf, sizeof(buf));
 fprintf(f, "Unicode version %s", buf);
 }
 
@@ -3046,9 +3046,9 @@ fprintf(f, "Unicode version %s", buf);
 static void
 print_jit_target(FILE *f)
 {
-char buf[VERSION_SIZE];
-config_str(PCRE2_CONFIG_JITTARGET, buf);
+char *buf = config_str(PCRE2_CONFIG_JITTARGET, NULL, 0);
 fputs(buf, f);
+free(buf);
 }
 
 
diff --git a/src/pcre2test_inc.h b/src/pcre2test_inc.h
index c47074171..ce808a82f 100644
--- a/src/pcre2test_inc.h
+++ b/src/pcre2test_inc.h
@@ -558,24 +558,41 @@ return 0;
 
 Arguments:
   what       the item to read
-  where      the 8-bit buffer to receive the string
+  where      the 8-bit buffer to receive the string (NULLABLE)
+  size       sizeof(where) or 0 to ask for the buffer to be allocated
+
+Returns:     the string where the data was written
 */
 
-static void
-config_str(uint32_t what, char *where)
+static char *
+config_str(uint32_t what, char *where, int size)
 {
-int r1, r2;
-PCRE2_UCHAR buf[VERSION_SIZE];
+int r2;
+PCRE2_UCHAR *buf;
+int needed_len;
 
-r1 = pcre2_config(what, NULL);
-r2 = pcre2_config(what, buf);
-if (r1 < 0 || r1 != r2 || r1 >= VERSION_SIZE)
+needed_len = pcre2_config(what, NULL);
+if (needed_len <= 0)
   {
   cfprintf(clr_test_error, stderr, "pcre2test: Error in pcre2_config(%d)\n", what);
   exit(1);
   }
+else if (size != 0 && needed_len > size)
+  {
+  cfprintf(clr_test_error, stderr,
+    "pcre2test: Static buffer provided to pcre2_config(%d) too small\n", what);
+  exit(1);
+  }
+
+buf = malloc(needed_len * sizeof(PCRE2_UCHAR));
+r2 = pcre2_config(what, buf);
+PCRE2_ASSERT(r2 == needed_len);
+
+if (where == NULL) where = malloc(needed_len);
+while (r2-- > 0) where[r2] = (char)buf[r2];
+free(buf);
 
-while (r1-- > 0) where[r1] = (char)buf[r1];
+return where;
 }