[core] allocate pcre output vector on demand

allocate pcre output vector on demand for saved config captures
(similar to what is done in lighttpd for pcre2 support)

src/configfile-glue.c

@@ -687,16 +687,18 @@ static int config_pcre_match(request_st * const r, const data_config * const dc,
                          matches, sizeof(matches)/sizeof(*matches));
     }
 
-    #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[capture_offset] = r->cond_match_data + capture_offset;
+    if (__builtin_expect( (NULL == cond_match->matches), 0)) {
+        /*(allocate on demand)*/
+        cond_match->matches = malloc(dc->ovec_nelts * sizeof(int *));
+        force_assert(cond_match->matches);
+    }
     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,
-                cond_match->matches, elementsof(cond_match->matches));
+                cond_match->matches, dc->ovec_nelts);
     return cond_match->captures;
 
   #else

src/configfile.h

@@ -41,6 +41,7 @@ struct data_config {
   #elif defined(HAVE_PCRE_H)
 	void *regex;
 	struct pcre_extra *regex_study;
+	int ovec_nelts;
   #endif
 	int capture_idx;
 	int ext;

src/data_config.c

@@ -166,6 +166,7 @@ int data_config_pcre_compile(data_config * const dc, const int pcre_jit, log_err
                   dc->string.ptr);
         return 0;
     }
+    dc->ovec_nelts = 3 * (captures + 1);
     return 1;
 
   #else

src/plugin_config.h

@@ -173,12 +173,9 @@ typedef struct cond_match_t {
     const buffer *comp_value; /* just a pointer */
  #ifdef HAVE_PCRE2_H
     struct pcre2_real_match_data_8 *match_data;
-    int captures;
-    void *matches; /* (PCRE2_SIZE *) */
- #elif defined(HAVE_PCRE_H)
-    int captures;
-    int matches[3 * 10];
  #endif
+    int captures;
+    void *matches; /* pcre2:(PCRE2_SIZE *), pcre:(int *) */
 } cond_match_t;
 
 int config_check_cond(request_st *r, int context_ndx);

src/reqpool.c

@@ -232,12 +232,15 @@ request_free_data (request_st * const r)
     free(r->cond_cache);
   #ifdef HAVE_PCRE
     if (r->cond_match_data) {
-      #ifdef HAVE_PCRE2_H
         for (int i = 0, used = r->con->srv->config_captures; i < used; ++i) {
+          #ifdef HAVE_PCRE2_H
             if (r->cond_match_data[i].match_data)
                 pcre2_match_data_free(r->cond_match_data[i].match_data);
+          #else /* HAVE_PCRE_H */
+            if (r->cond_match_data[i].matches)
+                free(r->cond_match_data[i].matches);
+          #endif
         }
-      #endif
         free(r->cond_match_data);
         free(r->cond_match);
     }

src/t/test_keyvalue.c

@@ -67,12 +67,14 @@ static void test_keyvalue_pcre_keyvalue_buffer_process (void) {
     cache.captures = 2;
   #ifdef HAVE_PCRE2_H
     PCRE2_SIZE matches[4];
-    cache.matches = matches;
+  #else /* HAVE_PCRE_H */
+    int matches[4];
   #endif
-    cache.matches[0] = 0;
-    cache.matches[1] = 15;
-    cache.matches[2] = 0;
-    cache.matches[3] = 3;
+    matches[0] = 0;
+    matches[1] = 15;
+    matches[2] = 0;
+    matches[3] = 3;
+    cache.matches = matches;
 
     /* converted from prior sparse tests/mod-redirect.t and tests/mod-rewrite.t
      * (real-world use should prefer ${url.path} and ${qsa} in substitutions)