MINOR: map: Add regex matching replacement

This patch declares a new map which provides a string based on
a string with back references replaced by the content matched
by the regex.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 7dd5744..25b94af 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -11815,13 +11815,19 @@
   -----------+--------------+-----------------+-----------------+---------------
     str      | end          | map_end         | map_end_int     | map_end_ip
   -----------+--------------+-----------------+-----------------+---------------
-    str      | reg          | map_reg         | map_reg_int     | map_reg_ip
+             |              | map_reg         |                 |
+    str      | reg          +-----------------+ map_reg_int     | map_reg_ip
+             |              | map_regm        |                 |
   -----------+--------------+-----------------+-----------------+---------------
     int      | int          | map_int         | map_int_int     | map_int_ip
   -----------+--------------+-----------------+-----------------+---------------
     ip       | ip           | map_ip          | map_ip_int      | map_ip_ip
   -----------+--------------+-----------------+-----------------+---------------
 
+  The special map called "map_regm" expect matching zone in the regular
+  expression and modify the output replacing back reference (like "\1") by
+  the corresponding match text.
+
   The file contains one key + value per line. Lines which start with '#' are
   ignored, just like empty lines. Leading tabs and spaces are stripped. The key
   is then the first "word" (series of non-space/tabs characters), and the value
diff --git a/include/proto/pattern.h b/include/proto/pattern.h
index 0a132f2..9c93db9 100644
--- a/include/proto/pattern.h
+++ b/include/proto/pattern.h
@@ -67,6 +67,7 @@
 int pat_idx_list_ptr(struct pattern_expr *expr, struct pattern *pat, char **err);
 int pat_idx_list_str(struct pattern_expr *expr, struct pattern *pat, char **err);
 int pat_idx_list_reg(struct pattern_expr *expr, struct pattern *pat, char **err);
+int pat_idx_list_regm(struct pattern_expr *expr, struct pattern *pat, char **err);
 int pat_idx_tree_ip(struct pattern_expr *expr, struct pattern *pat, char **err);
 int pat_idx_tree_str(struct pattern_expr *expr, struct pattern *pat, char **err);
 int pat_idx_tree_pfx(struct pattern_expr *expr, struct pattern *pat, char **err);
@@ -174,6 +175,7 @@
  * and restores the previous character when leaving.
  */
 struct pattern *pat_match_reg(struct sample *smp, struct pattern_expr *expr, int fill);
+struct pattern *pat_match_regm(struct sample *smp, struct pattern_expr *expr, int fill);
 
 /*
  * pattern_ref manipulation.
diff --git a/include/types/pattern.h b/include/types/pattern.h
index a71c343..912e086 100644
--- a/include/types/pattern.h
+++ b/include/types/pattern.h
@@ -87,6 +87,7 @@
 	PAT_MATCH_DOM,   /* domain-like sub-string (str) */
 	PAT_MATCH_END,   /* end of string (str) */
 	PAT_MATCH_REG,   /* regex (str -> reg) */
+	PAT_MATCH_REGM,  /* regex (str -> reg) with match zones */
 	/* keep this one last */
 	PAT_MATCH_NUM
 };
diff --git a/src/map.c b/src/map.c
index 35feea9..a28ceda 100644
--- a/src/map.c
+++ b/src/map.c
@@ -163,6 +163,7 @@
 {
 	struct map_descriptor *desc;
 	struct pattern *pat;
+	struct chunk *str;
 
 	/* get config */
 	desc = arg_p[0].data.map;
@@ -172,8 +173,19 @@
 
 	/* Match case. */
 	if (pat) {
-		/* Copy sample. */
 		if (pat->data) {
+			/* In the regm case, merge the sample with the input. */
+			if ((long)private == PAT_MATCH_REGM) {
+				str = get_trash_chunk();
+				str->len = exp_replace(str->str, str->size, smp->data.u.str.str,
+				                       pat->data->u.str.str,
+				                       (regmatch_t *)smp->ctx.a[0]);
+				if (str->len == -1)
+					return 0;
+				smp->data.u.str = *str;
+				return 1;
+			}
+			/* Copy sample. */
 			smp->data = *pat->data;
 			smp->flags |= SMP_F_CONST;
 			return 1;
@@ -242,6 +254,7 @@
 	{ "map_dom",     sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_STR,  SMP_T_STR,  (void *)PAT_MATCH_DOM },
 	{ "map_end",     sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_STR,  SMP_T_STR,  (void *)PAT_MATCH_END },
 	{ "map_reg",     sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_STR,  SMP_T_STR,  (void *)PAT_MATCH_REG },
+	{ "map_regm",    sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_STR,  SMP_T_STR,  (void *)PAT_MATCH_REGM},
 	{ "map_int",     sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_SINT, SMP_T_STR,  (void *)PAT_MATCH_INT },
 	{ "map_ip",      sample_conv_map, ARG2(1,STR,STR), sample_load_map, SMP_T_ADDR, SMP_T_STR,  (void *)PAT_MATCH_IP  },
 
diff --git a/src/pattern.c b/src/pattern.c
index 254c106..b4cb8e9 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -41,6 +41,7 @@
 	[PAT_MATCH_DOM]   = "dom",
 	[PAT_MATCH_END]   = "end",
 	[PAT_MATCH_REG]   = "reg",
+	[PAT_MATCH_REGM]  = "regm",
 };
 
 int (*pat_parse_fcts[PAT_MATCH_NUM])(const char *, struct pattern *, int, char **) = {
@@ -57,6 +58,7 @@
 	[PAT_MATCH_DOM]   = pat_parse_str,
 	[PAT_MATCH_END]   = pat_parse_str,
 	[PAT_MATCH_REG]   = pat_parse_reg,
+	[PAT_MATCH_REGM]  = pat_parse_reg,
 };
 
 int (*pat_index_fcts[PAT_MATCH_NUM])(struct pattern_expr *, struct pattern *, char **) = {
@@ -73,6 +75,7 @@
 	[PAT_MATCH_DOM]   = pat_idx_list_str,
 	[PAT_MATCH_END]   = pat_idx_list_str,
 	[PAT_MATCH_REG]   = pat_idx_list_reg,
+	[PAT_MATCH_REGM]  = pat_idx_list_regm,
 };
 
 void (*pat_delete_fcts[PAT_MATCH_NUM])(struct pattern_expr *, struct pat_ref_elt *) = {
@@ -89,6 +92,7 @@
 	[PAT_MATCH_DOM]   = pat_del_list_ptr,
 	[PAT_MATCH_END]   = pat_del_list_ptr,
 	[PAT_MATCH_REG]   = pat_del_list_reg,
+	[PAT_MATCH_REGM]  = pat_del_list_reg,
 };
 
 void (*pat_prune_fcts[PAT_MATCH_NUM])(struct pattern_expr *) = {
@@ -105,6 +109,7 @@
 	[PAT_MATCH_DOM]   = pat_prune_ptr,
 	[PAT_MATCH_END]   = pat_prune_ptr,
 	[PAT_MATCH_REG]   = pat_prune_reg,
+	[PAT_MATCH_REGM]  = pat_prune_reg,
 };
 
 struct pattern *(*pat_match_fcts[PAT_MATCH_NUM])(struct sample *, struct pattern_expr *, int) = {
@@ -121,6 +126,7 @@
 	[PAT_MATCH_DOM]   = pat_match_dom,
 	[PAT_MATCH_END]   = pat_match_end,
 	[PAT_MATCH_REG]   = pat_match_reg,
+	[PAT_MATCH_REGM]  = pat_match_regm,
 };
 
 /* Just used for checking configuration compatibility */
@@ -138,6 +144,7 @@
 	[PAT_MATCH_DOM]   = SMP_T_STR,
 	[PAT_MATCH_END]   = SMP_T_STR,
 	[PAT_MATCH_REG]   = SMP_T_STR,
+	[PAT_MATCH_REGM]  = SMP_T_STR,
 };
 
 /* this struct is used to return information */
@@ -540,6 +547,30 @@
 }
 
 /* Executes a regex. It temporarily changes the data to add a trailing zero,
+ * and restores the previous character when leaving. This function fills
+ * a matching array.
+ */
+struct pattern *pat_match_regm(struct sample *smp, struct pattern_expr *expr, int fill)
+{
+	struct pattern_list *lst;
+	struct pattern *pattern;
+	struct pattern *ret = NULL;
+
+	list_for_each_entry(lst, &expr->patterns, list) {
+		pattern = &lst->pat;
+
+		if (regex_exec_match2(pattern->ptr.reg, smp->data.u.str.str, smp->data.u.str.len,
+		                      MAX_MATCH, pmatch, 0)) {
+			ret = pattern;
+			smp->ctx.a[0] = pmatch;
+			break;
+		}
+	}
+
+	return ret;
+}
+
+/* Executes a regex. It temporarily changes the data to add a trailing zero,
  * and restores the previous character when leaving.
  */
 struct pattern *pat_match_reg(struct sample *smp, struct pattern_expr *expr, int fill)
@@ -1146,7 +1177,7 @@
 	return 1;
 }
 
-int pat_idx_list_reg(struct pattern_expr *expr, struct pattern *pat, char **err)
+int pat_idx_list_reg_cap(struct pattern_expr *expr, struct pattern *pat, int cap, char **err)
 {
 	struct pattern_list *patl;
 
@@ -1169,7 +1200,8 @@
 	}
 
 	/* compile regex */
-	if (!regex_comp(pat->ptr.str, patl->pat.ptr.reg, !(expr->mflags & PAT_MF_IGNORE_CASE), 0, err)) {
+	if (!regex_comp(pat->ptr.str, patl->pat.ptr.reg,
+	                !(expr->mflags & PAT_MF_IGNORE_CASE), cap, err)) {
 		free(patl->pat.ptr.reg);
 		free(patl);
 		return 0;
@@ -1183,6 +1215,16 @@
 	return 1;
 }
 
+int pat_idx_list_reg(struct pattern_expr *expr, struct pattern *pat, char **err)
+{
+	return pat_idx_list_reg_cap(expr, pat, 0, err);
+}
+
+int pat_idx_list_regm(struct pattern_expr *expr, struct pattern *pat, char **err)
+{
+	return pat_idx_list_reg_cap(expr, pat, 1, err);
+}
+
 int pat_idx_tree_ip(struct pattern_expr *expr, struct pattern *pat, char **err)
 {
 	unsigned int mask;