[gmime] Implemented custom header writer for References

[Jeffrey Stedfast <fejj src gnome org>]

commit a248cc044c6ad55505939363aa858c930867a014
Author: Jeffrey Stedfast <fejj gnome org>
Date:   Sun Sep 29 13:23:30 2013 -0400

    Implemented custom header writer for References
    
    2013-09-29  Jeffrey Stedfast  <fejj gnome org>
    
        * gmime/gmime-message.c (write_references): Custom writer for
        References headers so that individual msgid tokens do not get
        folded. Fixes bug #709031.

 ChangeLog             |    6 +++++
 gmime/gmime-message.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 3 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index c0e414f..79587b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-09-29  Jeffrey Stedfast  <fejj gnome org>
+
+       * gmime/gmime-message.c (write_references): Custom writer for
+       References headers so that individual msgid tokens do not get
+       folded. Fixes bug #709031.
+
 2013-09-26  Jeffrey Stedfast  <fejj gnome org>
 
        * gmime/gmime.c (g_mime_init): Initialize the mutexes
diff --git a/gmime/gmime-message.c b/gmime/gmime-message.c
index 1b92577..170116b 100644
--- a/gmime/gmime-message.c
+++ b/gmime/gmime-message.c
@@ -67,7 +67,8 @@ static char *message_get_headers (GMimeObject *object);
 static ssize_t message_write_to_stream (GMimeObject *object, GMimeStream *stream);
 static void message_encode (GMimeObject *object, GMimeEncodingConstraint constraint);
 
-static ssize_t write_structured (GMimeStream *stream, const char *name, const char *value);
+/*static ssize_t write_structured (GMimeStream *stream, const char *name, const char *value);*/
+static ssize_t write_references (GMimeStream *stream, const char *name, const char *value);
 static ssize_t write_addrspec (GMimeStream *stream, const char *name, const char *value);
 static ssize_t write_received (GMimeStream *stream, const char *name, const char *value);
 static ssize_t write_subject (GMimeStream *stream, const char *name, const char *value);
@@ -233,7 +234,7 @@ g_mime_message_init (GMimeMessage *message, GMimeMessageClass *klass)
        g_mime_header_list_register_writer (headers, "Subject", write_subject);
        g_mime_header_list_register_writer (headers, "Received", write_received);
        g_mime_header_list_register_writer (headers, "Message-Id", write_msgid);
-       g_mime_header_list_register_writer (headers, "References", write_structured);
+       g_mime_header_list_register_writer (headers, "References", write_references);
 }
 
 static void
@@ -618,12 +619,54 @@ write_subject (GMimeStream *stream, const char *name, const char *value)
 static ssize_t
 write_msgid (GMimeStream *stream, const char *name, const char *value)
 {
-       /* we don't want to wrap the Message-Id header - seems to
+       /* Note: we don't want to wrap the Message-Id header - seems to
           break a lot of clients (and servers) */
        return g_mime_stream_printf (stream, "%s: %s\n", name, value);
 }
 
 static ssize_t
+write_references (GMimeStream *stream, const char *name, const char *value)
+{
+       GMimeReferences *references, *reference;
+       ssize_t nwritten;
+       GString *folded;
+       size_t len, n;
+       
+       /* Note: we don't want to break in the middle of msgid tokens as
+          it seems to break a lot of clients (and servers) */
+       references = g_mime_references_decode (value);
+       folded = g_string_new (name);
+       g_string_append_len (folded, ": ", 2);
+       len = folded->len;
+       
+       reference = references;
+       while (reference != NULL) {
+               n = strlen (reference->msgid);
+               if (len > 1 && len + n + 1 >= GMIME_FOLD_LEN) {
+                       g_string_append_len (folded, "\n\t", 2);
+                       len = 1;
+               } else {
+                       g_string_append_len (folded, " ", 1);
+                       len++;
+               }
+               
+               g_string_append_len (folded, reference->msgid, n);
+               len += n;
+               
+               reference = reference->next;
+       }
+       
+       g_mime_references_clear (&references);
+       
+       g_string_append_len (folded, "\n", 1);
+       nwritten = g_mime_stream_write (stream, folded->str, folded->len);
+       g_string_free (folded, TRUE);
+       
+       return nwritten;
+}
+
+#if 0
+static ssize_t
 write_structured (GMimeStream *stream, const char *name, const char *value)
 {
        char *folded;
@@ -635,6 +678,7 @@ write_structured (GMimeStream *stream, const char *name, const char *value)
        
        return n;
 }
+#endif
 
 static ssize_t
 write_addrspec (GMimeStream *stream, const char *name, const char *value)