From dee26e2e1272a9d9eef3934bcfb5b80ac4686c7e Mon Sep 17 00:00:00 2001
From: Bram Matthys <syzop@vulnscan.org>
Date: Fri, 5 Jun 2026 09:58:16 +0200
Subject: [PATCH] Add const to third argument of unreal_create_match()

---
 doc/RELEASE-NOTES.md         |  3 +++
 include/h.h                  |  2 +-
 src/conf.c                   |  2 +-
 src/match.c                  |  2 +-
 src/modules/rpc/spamfilter.c |  2 +-
 src/modules/tkl.c            | 10 +++++-----
 src/modules/tkldb.c          |  2 +-
 7 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/doc/RELEASE-NOTES.md b/doc/RELEASE-NOTES.md
index fa175efc7..3d66a1c20 100644
--- a/doc/RELEASE-NOTES.md
+++ b/doc/RELEASE-NOTES.md
@@ -22,6 +22,9 @@ This is work in progress and may not always be a stable version.
   at 1MB like in 6.2.5 (`DOWNLOAD_MAX_SIZE_MEMORY_BACKED`).
 * The `unreal_match()` function now has a 3rd argument `const char **error`
   for communicating regex errors back. Just set to `NULL` if you don't care.
+* Similarly, `unreal_create_match()` last argument is now `const char **error`
+  (const was added). So when callers use that, their variable `char *err`
+  needs to become `const char *err`.
 * If you do something to a user that would (potentially) move the user from
   `unknown-users` to `known-users` (or vice versa) then you should call
   `update_known_user_cache(client);` to update the known users cache.
diff --git a/include/h.h b/include/h.h
index 85c074631..d24ff3b39 100644
--- a/include/h.h
+++ b/include/h.h
@@ -1093,7 +1093,7 @@ extern int parse_chanmode(ParseMode *pm, const char *modebuf_in, const char *par
 extern int dead_socket(Client *to, const char *notice);
 extern MODVAR pcre2_match_context *unreal_pcre2_match_ctx;
 extern void init_match(void);
-extern Match *unreal_create_match(MatchType type, const char *str, char **error);
+extern Match *unreal_create_match(MatchType type, const char *str, const char **error);
 extern void unreal_delete_match(Match *m);
 extern int unreal_match(Match *m, const char *str, const char **error);
 extern int unreal_match_method_strtoval(const char *str);
diff --git a/src/conf.c b/src/conf.c
index 0c91ec64e..6c51a2718 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -10624,7 +10624,7 @@ int _test_alias(ConfigFile *conf, ConfigEntry *ce) {
 			continue;
 		}
 		if (!strcmp(cep->name, "format")) {
-			char *err = NULL;
+			const char *err = NULL;
 			Match *expr;
 			char has_type = 0, has_target = 0, has_parameters = 0;
 
diff --git a/src/match.c b/src/match.c
index 36e55c4b4..2c27e58f9 100644
--- a/src/match.c
+++ b/src/match.c
@@ -397,7 +397,7 @@ void unreal_delete_match(Match *m)
 	safe_free(m);
 }
 
-Match *unreal_create_match(MatchType type, const char *str, char **error)
+Match *unreal_create_match(MatchType type, const char *str, const char **error)
 {
 	Match *m = safe_alloc(sizeof(Match));
 	static char errorbuf[512];
diff --git a/src/modules/rpc/spamfilter.c b/src/modules/rpc/spamfilter.c
index a10bf73ab..bae953101 100644
--- a/src/modules/rpc/spamfilter.c
+++ b/src/modules/rpc/spamfilter.c
@@ -210,7 +210,7 @@ RPC_CALL_FUNC(rpc_spamfilter_add)
 	char targetbuf[64];
 	char actionbuf[2];
 	char reasonbuf[512];
-	char *err = NULL;
+	const char *err = NULL;
 
 	if (!spamfilter_select_criteria(client, request, params, &name, &match_type, &targets, targetbuf, sizeof(targetbuf), &action, actionbuf))
 		return; /* Error already communicated to client */
diff --git a/src/modules/tkl.c b/src/modules/tkl.c
index d144aba15..d268cf008 100644
--- a/src/modules/tkl.c
+++ b/src/modules/tkl.c
@@ -533,7 +533,7 @@ int tkl_config_test_spamfilter(ConfigFile *cf, ConfigEntry *ce, int type, int *e
 	if (match && match_type)
 	{
 		Match *m;
-		char *err;
+		const char *err;
 
 		m = unreal_create_match(match_type, match, &err);
 		if (!m)
@@ -733,7 +733,7 @@ int tkl_config_run_spamfilter(ConfigFile *cf, ConfigEntry *ce, int type)
 
 	if (match)
 	{
-		char *err;
+		const char *err;
 		m = unreal_create_match(match_type, match, &err);
 		if (!m)
 		{
@@ -1227,7 +1227,7 @@ void recompile_spamfilters(void)
 {
 	TKL *tkl;
 	Match *m;
-	char *err;
+	const char *err;
 	int converted = 0;
 	int index;
 
@@ -2517,7 +2517,7 @@ CMD_FUNC(cmd_spamfilter)
 	int n;
 	Match *m;
 	int match_type = 0;
-	char *err = NULL;
+	const char *err = NULL;
 
 	if (IsServer(client))
 		return;
@@ -4741,7 +4741,7 @@ CMD_FUNC(cmd_tkl_add)
 		BanActionValue action;
 		unsigned short target;
 		/* helper variables */
-		char *err;
+		const char *err;
 
 		if (parc < 12)
 		{
diff --git a/src/modules/tkldb.c b/src/modules/tkldb.c
index f18efe4d5..21f9baa7a 100644
--- a/src/modules/tkldb.c
+++ b/src/modules/tkldb.c
@@ -678,7 +678,7 @@ int read_tkldb(void)
 		if (TKLIsSpamfilter(tkl))
 		{
 			int match_method;
-			char *err = NULL;
+			const char *err = NULL;
 
 			tkl->ptr.spamfilter = safe_alloc(sizeof(Spamfilter));