conf: ignore trailing non-root zone name dot in %s formatter

doc/man/knot.conf.5in

@@ -491,14 +491,15 @@ A path to the zone file. Non absolute path is relative to
 \fI\%storage\fP\&. It is also possible to use the following formatters:
 .INDENT 0.0
 .IP \(bu 2
-\fI%s\fP \- means the current zone name in the textual representation (beware of special
-characters which are escaped or encoded in the \eDDD form). Each zone name is
-terminated with a dot character!
+\fB%s\fP \- means the current zone name in the textual representation (beware
+of special characters which are escaped or encoded in the \eDDD form where
+DDD is corresponding decimal ASCII code). The zone name doesn\(aqt include the
+terminating dot, except for the root zone.
 .IP \(bu 2
-\fI%%\fP \- means the \fI%\fP character
+\fB%%\fP \- means the \fB%\fP character
 .UNINDENT
 .sp
-Default: \fI\%storage\fP/\fB%s\fPzone
+Default: \fI\%storage\fP/\fB%s\fP\&.zone
 .SS storage
 .sp
 A data directory for storing zone files, journal files and timers database.

doc/reference.rst

@@ -584,14 +584,15 @@ file
 ----
 
 A path to the zone file. Non absolute path is relative to
-:ref:`storage<zone_storage>`. It is also possible to use the following formatters: 
+:ref:`storage<zone_storage>`. It is also possible to use the following formatters:
 
-- `%s` - means the current zone name in the textual representation (beware of special
-  characters which are escaped or encoded in the \\DDD form). Each zone name is
-  terminated with a dot character!
-- `%%` - means the `%` character
+- ``%s`` - means the current zone name in the textual representation (beware
+  of special characters which are escaped or encoded in the \\DDD form where
+  DDD is corresponding decimal ASCII code). The zone name doesn't include the
+  terminating dot, except for the root zone.
+- ``%%`` - means the ``%`` character
 
-Default: :ref:`storage<zone_storage>`/``%s``\ zone
+Default: :ref:`storage<zone_storage>`/``%s``\ .zone
 
 .. _zone_storage:
 

src/knot/conf/conf.c

@@ -649,11 +649,18 @@ static char* get_filename(
 			}
 
 			// Replace possible slashes with underscores.
-			for (char *ch = buff; *ch != '\0'; ch++) {
+			char *ch;
+			for (ch = buff; *ch != '\0'; ch++) {
 				if (*ch == '/') {
 					*ch = '_';
 				}
 			}
+
+			// Remove trailing dot if not root zone.
+			if (ch - buff > 1) {
+				*(--ch) = '\0';
+			}
+
 			break;
 		case '\0':
 			CONF_LOG_ZONE(LOG_WARNING, zone, "ignoring missing "
@@ -699,7 +706,7 @@ char* conf_zonefile_txn(
 
 	// Use default zonefile name pattern if not specified.
 	if (file == NULL) {
-		file = "%szone";
+		file = "%s.zone";
 	}
 
 	return get_filename(conf, txn, zone, file);
@@ -714,7 +721,7 @@ char* conf_journalfile_txn(
 		return NULL;
 	}
 
-	return get_filename(conf, txn, zone, "%sdb");
+	return get_filename(conf, txn, zone, "%s.db");
 }
 
 size_t conf_udp_threads_txn(

tests/conf.c

@@ -20,6 +20,7 @@
 
 #define ZONE1	"0/25.2.0.192.in-addr.arpa."
 #define ZONE2	"."
+#define ZONE3	"x."
 
 static void test_conf_zonefile(void)
 {
@@ -30,6 +31,8 @@ static void test_conf_zonefile(void)
 	ok(zone1 != NULL, "create dname "ZONE1);
 	knot_dname_t *zone2 = knot_dname_from_str_alloc(ZONE2);
 	ok(zone2 != NULL, "create dname "ZONE2);
+	knot_dname_t *zone3 = knot_dname_from_str_alloc(ZONE3);
+	ok(zone3 != NULL, "create dname "ZONE3);
 
 	const char *conf_str =
 		"template:\n"
@@ -38,9 +41,10 @@ static void test_conf_zonefile(void)
 		"\n"
 		"zone:\n"
 		"  - domain: "ZONE1"\n"
-		"    file: dir/a%%b/%ssuffix/%a\n"
-		"zone:\n"
+		"    file: dir/a%%b/%s.suffix/%a\n"
 		"  - domain: "ZONE2"\n"
+		"    file: /%s\n"
+		"  - domain: "ZONE3"\n"
 		"    file: /%s\n";
 
 	ret = test_conf(conf_str, NULL);
@@ -64,9 +68,19 @@ static void test_conf_zonefile(void)
 		free(file);
 	}
 
+	// Absolute path without formatters.
+	file = conf_zonefile(conf(), zone3);
+	ok(file != NULL, "Get zonefile path for "ZONE3);
+	if (file != NULL) {
+		ok(strcmp(file, "/x") == 0,
+		          "Zonefile path compare for "ZONE3);
+		free(file);
+	}
+
 	conf_free(conf(), false);
 	knot_dname_free(&zone1, NULL);
 	knot_dname_free(&zone2, NULL);
+	knot_dname_free(&zone3, NULL);
 }
 
 int main(int argc, char *argv[])