Because gettext is allowed to do as it pleases...

...when it is fed with an empty string, let's workaround it by adding
a new function.

src/gettext.cpp

@@ -4,6 +4,11 @@
 
 #include <cstring>
 
+char const *egettext(char const *msgid)
+{
+	return msgid[0] == '\0' ? msgid : gettext(msgid);
+}
+
 const char* sgettext (const char *msgid)
 {
 	const char *msgval = gettext (msgid);

src/gettext.hpp

@@ -5,6 +5,8 @@
 
 // gettext-related declarations
 #include <libintl.h>
+
+const char* egettext (const char*);
 const char* sgettext (const char*);
 const char* dsgettext (const char * domainname, const char *msgid);
 std::string vgettext (const char*,const string_map&);