Bug#356356: nullmailer: doesn't permit mail from <>

[Nick Leverton]

This patch does the same for nullmailer-inject.

To the best of my knowledge, Return-Path is always the most recent
sender.  So if we're taking the envelope from the existing headers then
Return-Path should be still used, even where there is a Resent-From.

But - sorry Norbert, I just realised I haven't tested the cases where
the Return-Path is <>, so please hold off on these until I get the chance.

Nick

--- nullmailer-1.02/src/inject.cc.orig  2005-11-10 16:11:12.000000000 +0000
+++ nullmailer-1.02/src/inject.cc       2006-03-11 17:54:29.000000000 +0000
@@ -100,6 +100,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 static slist recipients;
 static mystring sender;
+static bool use_header_sender = true;
 static bool use_header_recips = true;
 
 void parse_recips(const mystring& list)
@@ -165,7 +166,8 @@
        return true;
       if(is_resent) {
        if(!header_is_resent) {
-         sender = "";
+         // if(use_header_sender)      // There is no Resent-Return-Path
+         //   sender = "";
          if(use_header_recips)
            recipients.empty();
        }
@@ -187,7 +189,7 @@
              parse_recips(list);
          }
          else if(is_sender) {
-           if(is_resent == header_is_resent && !sender)
+           if(is_resent == header_is_resent && use_header_sender)
              parse_sender(list);
          }
        }
@@ -282,7 +284,7 @@
   if(!shost) shost = host;
   canonicalize(shost);
   
-  if(!sender)
+  if(use_header_sender && !sender)
     sender = suser + "@" + shost;
 }
 
@@ -542,11 +544,13 @@
   if(o_from) {
     mystring list;
     mystring tmp(o_from);
-    if(!parse_addresses(tmp, list) ||
-       !parse_sender(list)) {
+    if(tmp != "" && 
+      (!parse_addresses(tmp, list) ||
+       !parse_sender(list))) {
       fout << "nullmailer-inject: Invalid sender address: " << o_from << endl;
       return false;
     }
+    use_header_sender = false;
   }
   use_header_recips = (use_recips != use_args);
   if(use_recips == use_header)