From 670b3a395ff6365bc92889d5aafd72e362dc97c2 Mon Sep 17 00:00:00 2001
From: Glenn Strauss <gstrauss@gluelogic.com>
Date: Mon, 22 Nov 2021 00:49:48 -0500
Subject: [PATCH] [core] allocate one fewer cond_match_t, if needed

allocate one fewer cond_match_t in r->cond_match_data, if any are needed
---
 src/configfile-glue.c | 6 ++++--
 src/configfile.c      | 3 ---
 src/h2.c              | 2 +-
 src/mod_redirect.c    | 2 +-
 src/mod_rewrite.c     | 2 +-
 5 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/configfile-glue.c b/src/configfile-glue.c
index f4fbea41..7602e419 100644
--- a/src/configfile-glue.c
+++ b/src/configfile-glue.c
@@ -651,8 +651,9 @@ static int config_pcre_match(request_st * const r, const data_config * const dc,
         return pcre2_match(dc->code, (PCRE2_SPTR)BUF_PTR_LEN(b),
                            0, 0, dc->match_data, NULL);
 
+    const int capture_offset = dc->capture_idx - 1;
     cond_match_t * const cond_match =
-      r->cond_match[dc->capture_idx] = r->cond_match_data + dc->capture_idx;
+      r->cond_match[capture_offset] = r->cond_match_data + capture_offset;
     pcre2_match_data *match_data = cond_match->match_data;
     if (__builtin_expect( (NULL == match_data), 0)) {
         /*(allocate on demand)*/
@@ -689,8 +690,9 @@ static int config_pcre_match(request_st * const r, const data_config * const dc,
     #ifndef elementsof
     #define elementsof(x) (sizeof(x) / sizeof(x[0]))
     #endif
+    const int capture_offset = dc->capture_idx - 1;
     cond_match_t * const cond_match =
-      r->cond_match[dc->capture_idx] = r->cond_match_data + dc->capture_idx;
+      r->cond_match[capture_offset] = r->cond_match_data + capture_offset;
     cond_match->comp_value = b; /*holds pointer to b (!) for pattern subst*/
     cond_match->captures =
       pcre_exec(dc->regex, dc->regex_study, BUF_PTR_LEN(b), 0, 0,
diff --git a/src/configfile.c b/src/configfile.c
index fbc19fb2..5760bb43 100644
--- a/src/configfile.c
+++ b/src/configfile.c
@@ -1233,9 +1233,6 @@ int config_finalize(server *srv, const buffer *default_server_tag) {
         return 0;
     }
 
-    /* adjust cond_match_data list size if regex config conditions present */
-    if (srv->config_captures) ++srv->config_captures;
-
   #ifdef HAVE_PCRE2_H
     for (uint32_t i = 1; i < srv->config_context->used; ++i) {
         data_config * const dc =
diff --git a/src/h2.c b/src/h2.c
index 07b94071..0f8cca7c 100644
--- a/src/h2.c
+++ b/src/h2.c
@@ -2571,7 +2571,7 @@ h2_init_stream (request_st * const h2r, connection * const con)
     r->conditional_is_valid = h2r->conditional_is_valid;
     memcpy(r->cond_cache, h2r->cond_cache, used * sizeof(cond_cache_t));
   #ifdef HAVE_PCRE
-    if (srv->config_captures > 1)
+    if (srv->config_captures)
         memcpy(r->cond_match, h2r->cond_match,
                srv->config_captures * sizeof(cond_match_t));
   #endif
diff --git a/src/mod_redirect.c b/src/mod_redirect.c
index b64a997f..1bdfac5e 100644
--- a/src/mod_redirect.c
+++ b/src/mod_redirect.c
@@ -169,7 +169,7 @@ URIHANDLER_FUNC(mod_redirect_uri_handler) {
 
     ctx.cache = NULL;
     if (p->conf.redirect->x0) { /*(p->conf.redirect->x0 is capture_idx)*/
-        ctx.cache = r->cond_match[p->conf.redirect->x0];
+        ctx.cache = r->cond_match[p->conf.redirect->x0 - 1];
     }
     ctx.burl = &burl;
     burl.scheme    = &r->uri.scheme;
diff --git a/src/mod_rewrite.c b/src/mod_rewrite.c
index 352d8860..b4b50c51 100644
--- a/src/mod_rewrite.c
+++ b/src/mod_rewrite.c
@@ -291,7 +291,7 @@ static handler_t process_rewrite_rules(request_st * const r, plugin_data *p, con
 
 	ctx.cache = NULL;
 	if (kvb->x0) { /*(kvb->x0 is capture_idx)*/
-		ctx.cache = r->cond_match[kvb->x0];
+		ctx.cache = r->cond_match[kvb->x0 - 1];
         }
 	ctx.burl = &burl;
 	burl.scheme    = &r->uri.scheme;