settings: change fault value of regular_expressions to 'perl'

NEWS

@@ -1,6 +1,7 @@
 ncmpcpp-0.7.5 (????-??-??)
 * Action chains can be now used for seeking.
 * Fixed fetching artist info from last.fm.
+* Default value of regular_expressions was changed from 'basic' to 'perl' to work around boost issue (#12222).
 
 ncmpcpp 0.7.4 (2016-04-17)
 * Fetching lyrics from lyricwiki.org was fixed.

doc/config

@@ -428,7 +428,7 @@
 #
 ## Available values: none, basic, extended, perl.
 ##
-#regular_expressions = basic
+#regular_expressions = perl
 #
 ##
 ## Note: If below is enabled, ncmpcpp will ignore leading

src/settings.cpp

@@ -593,7 +593,7 @@ bool Configuration::read(const std::vector<std::string> &config_paths, bool igno
 		else
 			throw std::runtime_error("invalid argument: " + v);
 		regex_type |= boost::regex::icase;
-	}, defaults_to(regex_type, boost::regex::basic | boost::regex::icase)
+	}, defaults_to(regex_type, boost::regex::perl | boost::regex::icase)
 	));
 	p.add("ignore_leading_the", yes_no(
 		ignore_leading_the, false