MIME-16: wrap the log output of possibly NULL strings.

src/header_generator.cc

@@ -89,7 +89,7 @@ namespace
 
 void generate(std::string& out, sv header_name, const pEp_identity* id)
 {
-    LOG << "GEN_ID: " << id->username << " | " << id->address << std::endl;
+    LOG << "GEN_ID: " << NN(id->username) << " | " << NN(id->address) << std::endl;
     static BasicRules br;
     
     out += exists(id->username) ? encode_header_if_necessary(br.phrase, header_name, id->username, qp::Word) + " " : std::string() ;

src/pEpMIME_internal.hh

@@ -37,6 +37,7 @@
     
 #endif // C++17 switch
 
+#define NN(str) ( (str) ? (str) : "(NULL)" )
 
 #ifdef LOG_TO_STDERR
 #include <iostream>