Handle space issue with refstyle more downstream

It is not necessarily, and infers with some usages, to generally escape
spaces in labels and references

src/insets/InsetRef.cpp

@@ -288,6 +288,11 @@ void InsetRef::latex(otexstream & os, OutputParams const & rp) const
 		os << fcmd;
 		if (use_refstyle && use_plural)
 			os << "[s]";
+		if (contains(label, ' '))
+			// refstyle bug: labels with blanks need to be grouped
+			// otherwise the blanks will be gobbled
+			os << "{{" << label << "}}";
+		else
 			os << '{' << label << '}';
 	}
 	else if (cmd == "labelonly") {

src/support/lstrings.cpp

@@ -1237,7 +1237,7 @@ docstring const escape(docstring const & lab)
 	for (char_type const c : lab) {
 		if (c >= 128 || c == '=' || c == '%' || c == '#' || c == '$'
 		    || c == '}' || c == '{' || c == ']' || c == '[' || c == '&'
-		    || c == '\\' || c == ' ') // refstyle doesn't support spaces
+		    || c == '\\')
 		{
 			// Although char_type is a 32 bit type we know that
 			// UCS4 occupies only 21 bits, so we don't need to