MINOR: cfgparse/bind: suggest correct spelling for unknown bind keywords

Just like with the server keywords, now's the turn of "bind" keywords.
The difference is that 100% of the bind keywords are registered, thus
we do not need the list of extra keywords.

There are multiple bind line parsers today, all were updated:
  - peers
  - log
  - dgram-bind
  - cli

$ printf "listen f\nbind :8000 tcut\n" | ./haproxy -c -f /dev/stdin
[NOTICE] 070/101358 (25146) : haproxy version is 2.4-dev11-7b8787-26
[NOTICE] 070/101358 (25146) : path to executable is ./haproxy
[ALERT] 070/101358 (25146) : parsing [/dev/stdin:2] : 'bind :8000' unknown keyword 'tcut'; did you mean 'tcp-ut' maybe ?
[ALERT] 070/101358 (25146) : Error(s) found in configuration file : /dev/stdin
[ALERT] 070/101358 (25146) : Fatal errors found in configuration.
diff --git a/include/haproxy/listener.h b/include/haproxy/listener.h
index ee02b0c..e4cea50 100644
--- a/include/haproxy/listener.h
+++ b/include/haproxy/listener.h
@@ -167,6 +167,7 @@
 
 /* Dumps all registered "bind" keywords to the <out> string pointer. */
 void bind_dump_kws(char **out);
+const char *bind_find_best_kw(const char *word);
 
 void bind_recount_thread_bits(struct bind_conf *conf);
 unsigned int bind_map_thread_id(const struct bind_conf *conf, unsigned int r);
diff --git a/src/cfgparse-listen.c b/src/cfgparse-listen.c
index b60741a..ac50025 100644
--- a/src/cfgparse-listen.c
+++ b/src/cfgparse-listen.c
@@ -389,9 +389,8 @@
 
 		cur_arg = 2;
 		while (*(args[cur_arg])) {
-			static int bind_dumped;
 			struct bind_kw *kw;
-			char *err;
+			const char *best;
 
 			kw = bind_find_kw(args[cur_arg]);
 			if (kw) {
@@ -431,17 +430,13 @@
 				continue;
 			}
 
-			err = NULL;
-			if (!bind_dumped) {
-				bind_dump_kws(&err);
-				indent_msg(&err, 4);
-				bind_dumped = 1;
-			}
-
-			ha_alert("parsing [%s:%d] : '%s %s' unknown keyword '%s'.%s%s\n",
-				 file, linenum, args[0], args[1], args[cur_arg],
-				 err ? " Registered keywords :" : "", err ? err : "");
-			free(err);
+			best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				ha_alert("parsing [%s:%d] : '%s %s' unknown keyword '%s'; did you mean '%s' maybe ?\n",
+					 file, linenum, args[0], args[1], args[cur_arg], best);
+			else
+				ha_alert("parsing [%s:%d] : '%s %s' unknown keyword '%s'.\n",
+					 file, linenum, args[0], args[1], args[cur_arg]);
 
 			err_code |= ERR_ALERT | ERR_FATAL;
 			goto out;
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 9c8efa2..269b47d 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -609,7 +609,6 @@
 
 	if (strcmp(args[0], "bind") == 0 || strcmp(args[0], "default-bind") == 0) {
 		int cur_arg;
-		static int kws_dumped;
 		struct bind_conf *bind_conf;
 		struct bind_kw *kw;
 
@@ -689,17 +688,13 @@
 			cur_arg += 1 + kw->skip;
 		}
 		if (*args[cur_arg] != 0) {
-			char *kws = NULL;
-
-			if (!kws_dumped) {
-				kws_dumped = 1;
-				bind_dump_kws(&kws);
-				indent_msg(&kws, 4);
-			}
-			ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.%s%s\n",
-			         file, linenum, args[cur_arg], cursection,
-			         kws ? " Registered keywords :" : "", kws ? kws: "");
-			free(kws);
+			const char *best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section; did you mean '%s' maybe ?\n",
+					 file, linenum, args[cur_arg], cursection, best);
+			else
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.\n",
+					 file, linenum, args[cur_arg], cursection);
 			err_code |= ERR_ALERT | ERR_FATAL;
 			goto out;
 		}
diff --git a/src/cli.c b/src/cli.c
index 72919ce..04c4e7a 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -290,8 +290,8 @@
 
 		cur_arg = 3;
 		while (*args[cur_arg]) {
-			static int bind_dumped;
 			struct bind_kw *kw;
+			const char *best;
 
 			kw = bind_find_kw(args[cur_arg]);
 			if (kw) {
@@ -314,15 +314,13 @@
 				continue;
 			}
 
-			if (!bind_dumped) {
-				bind_dump_kws(err);
-				indent_msg(err, 4);
-				bind_dumped = 1;
-			}
-
-			memprintf(err, "'%s %s' : unknown keyword '%s'.%s%s",
-			          args[0], args[1], args[cur_arg],
-			          err && *err ? " Registered keywords :" : "", err && *err ? *err : "");
+			best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				memprintf(err, "'%s %s' : unknown keyword '%s'. Did you mean '%s' maybe ?",
+				          args[0], args[1], args[cur_arg], best);
+			else
+				memprintf(err, "'%s %s' : unknown keyword '%s'.",
+				          args[0], args[1], args[cur_arg]);
 			return -1;
 		}
 
@@ -2656,8 +2654,8 @@
 	cur_arg = 1;
 
 	while (*args[cur_arg]) {
-			static int bind_dumped;
 			struct bind_kw *kw;
+			const char *best;
 
 			kw = bind_find_kw(args[cur_arg]);
 			if (kw) {
@@ -2680,15 +2678,13 @@
 				continue;
 			}
 
-			if (!bind_dumped) {
-				bind_dump_kws(&err);
-				indent_msg(&err, 4);
-				bind_dumped = 1;
-			}
-
-			memprintf(&err, "'%s %s' : unknown keyword '%s'.%s%s",
-			          args[0], args[1], args[cur_arg],
-			          err ? " Registered keywords :" : "", err ? err : "");
+			best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				memprintf(&err, "'%s %s' : unknown keyword '%s'. Did you mean '%s' maybe ?",
+				          args[0], args[1], args[cur_arg], best);
+			else
+				memprintf(&err, "'%s %s' : unknown keyword '%s'.",
+				          args[0], args[1], args[cur_arg]);
 			goto err;
 	}
 
diff --git a/src/listener.c b/src/listener.c
index 4dfaa7f..882d17f 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -1261,6 +1261,37 @@
 	}
 }
 
+/* Try to find in srv_keyword the word that looks closest to <word> by counting
+ * transitions between letters, digits and other characters. Will return the
+ * best matching word if found, otherwise NULL.
+ */
+const char *bind_find_best_kw(const char *word)
+{
+	uint8_t word_sig[1024];
+	uint8_t list_sig[1024];
+	const struct bind_kw_list *kwl;
+	const char *best_ptr = NULL;
+	int dist, best_dist = INT_MAX;
+	int index;
+
+	make_word_fingerprint(word_sig, word);
+	list_for_each_entry(kwl, &bind_keywords.list, list) {
+		for (index = 0; kwl->kw[index].kw != NULL; index++) {
+			make_word_fingerprint(list_sig, kwl->kw[index].kw);
+			dist = word_fingerprint_distance(word_sig, list_sig);
+			if (dist < best_dist) {
+				best_dist = dist;
+				best_ptr = kwl->kw[index].kw;
+			}
+		}
+	}
+
+	if (best_dist > 2 * strlen(word) || (best_ptr && best_dist > 2 * strlen(best_ptr)))
+		best_ptr = NULL;
+
+	return best_ptr;
+}
+
 /************************************************************************/
 /*      All supported sample and ACL keywords must be declared here.    */
 /************************************************************************/
diff --git a/src/log.c b/src/log.c
index 2bf7f15..c771218 100644
--- a/src/log.c
+++ b/src/log.c
@@ -3894,7 +3894,6 @@
 	}
 	else if (strcmp(args[0], "bind") == 0) {
 		int cur_arg;
-		static int kws_dumped;
 		struct bind_conf *bind_conf;
 		struct bind_kw *kw;
 		struct listener *l;
@@ -3949,24 +3948,19 @@
 			cur_arg += 1 + kw->skip;
 		}
 		if (*args[cur_arg] != 0) {
-			char *kws = NULL;
-
-			if (!kws_dumped) {
-				kws_dumped = 1;
-				bind_dump_kws(&kws);
-				indent_msg(&kws, 4);
-			}
-			ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.%s%s\n",
-			         file, linenum, args[cur_arg], cursection,
-			         kws ? " Registered keywords :" : "", kws ? kws: "");
-			free(kws);
+			const char *best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section; did you mean '%s' maybe ?\n",
+					 file, linenum, args[cur_arg], cursection, best);
+			else
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.\n",
+					 file, linenum, args[cur_arg], cursection);
 			err_code |= ERR_ALERT | ERR_FATAL;
 			goto out;
 		}
 	}
 	else if (strcmp(args[0], "dgram-bind") == 0) {
 		int cur_arg;
-		static int kws_dumped;
 		struct bind_conf *bind_conf;
 		struct bind_kw *kw;
 		struct listener *l;
@@ -4015,17 +4009,13 @@
 			cur_arg += 1 + kw->skip;
 		}
 		if (*args[cur_arg] != 0) {
-			char *kws = NULL;
-
-			if (!kws_dumped) {
-				kws_dumped = 1;
-				bind_dump_kws(&kws);
-				indent_msg(&kws, 4);
-			}
-			ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.%s%s\n",
-			         file, linenum, args[cur_arg], cursection,
-				 kws ? " Registered keywords :" : "", kws ? kws: "");
-			free(kws);
+			const char *best = bind_find_best_kw(args[cur_arg]);
+			if (best)
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section; did you mean '%s' maybe ?\n",
+					 file, linenum, args[cur_arg], cursection, best);
+			else
+				ha_alert("parsing [%s:%d] : unknown keyword '%s' in '%s' section.\n",
+					 file, linenum, args[cur_arg], cursection);
 			err_code |= ERR_ALERT | ERR_FATAL;
 			goto out;
 		}