[evolution] I#590 - Redirect should not modify message headers

[Milan Crha <mcrha src gnome org>]

commit 170f7b296526d12f92e98f26ce8ce36e47a084cf
Author: Milan Crha <mcrha redhat com>
Date:   Tue Feb 18 19:43:52 2020 +0100

    I#590 - Redirect should not modify message headers
    
    Closes https://gitlab.gnome.org/GNOME/evolution/issues/590

 src/composer/e-msg-composer.c              | 27 ++++++++++++++++++++++++---
 src/libemail-engine/e-mail-folder-utils.c  |  8 +++++---
 src/libemail-engine/e-mail-session-utils.c |  3 ++-
 src/libemail-engine/mail-ops.c             |  3 ++-
 4 files changed, 33 insertions(+), 8 deletions(-)
---
diff --git a/src/composer/e-msg-composer.c b/src/composer/e-msg-composer.c
index cd3168d882..7f3aee36ae 100644
--- a/src/composer/e-msg-composer.c
+++ b/src/composer/e-msg-composer.c
@@ -67,6 +67,7 @@ struct _AsyncContext {
        GSList *recipients_with_certificate; /* EContact * */
 
        guint skip_content : 1;
+       guint is_redirect : 1;
        guint need_thread : 1;
        guint pgp_sign : 1;
        guint pgp_encrypt : 1;
@@ -543,7 +544,8 @@ build_message_headers (EMsgComposer *composer,
 
        /* Subject: */
        subject = e_composer_header_table_get_subject (table);
-       camel_mime_message_set_subject (message, subject);
+       if (!redirect || g_strcmp0 (subject, camel_mime_message_get_subject (message)) != 0)
+               camel_mime_message_set_subject (message, subject);
 
        if (source != NULL) {
                CamelMedium *medium;
@@ -627,6 +629,9 @@ build_message_headers (EMsgComposer *composer,
                g_object_unref (source);
        }
 
+       if (redirect)
+               camel_medium_set_header (CAMEL_MEDIUM (message), "X-Evolution-Is-Redirect", "1");
+
        /* Reply-To: */
        reply_to = e_composer_header_table_get_reply_to (table);
        if (reply_to != NULL && *reply_to != '\0') {
@@ -658,7 +663,22 @@ build_message_headers (EMsgComposer *composer,
        }
 
        /* Date: */
-       camel_mime_message_set_date (message, CAMEL_MESSAGE_DATE_CURRENT, 0);
+       if (redirect) {
+               struct tm local;
+               gint tz, offset;
+               time_t date;
+               gchar *datestr;
+
+               date = time (NULL);
+               camel_localtime_with_offset (date, &local, &tz);
+               offset = (((tz / 60 / 60) * 100) + (tz / 60 % 60));
+
+               datestr = camel_header_format_date (date, offset);
+               camel_medium_set_header (CAMEL_MEDIUM (message), "Resent-Date", datestr);
+               g_free (datestr);
+       } else {
+               camel_mime_message_set_date (message, CAMEL_MESSAGE_DATE_CURRENT, 0);
+       }
 
        /* X-Evolution-PostTo: */
        header = e_composer_header_table_get_header (
@@ -1296,6 +1316,7 @@ composer_build_message (EMsgComposer *composer,
                e_msg_composer_dec_soft_busy (composer);
 
                context->skip_content = TRUE;
+               context->is_redirect = TRUE;
                context->message = g_object_ref (priv->redirect);
                build_message_headers (composer, context->message, TRUE);
                g_simple_async_result_complete (simple);
@@ -1728,7 +1749,7 @@ composer_build_message_finish (EMsgComposer *composer,
                }
        }
 
-       if (context->top_level_part == context->text_plain_part) {
+       if (!context->is_redirect && context->top_level_part == context->text_plain_part) {
                camel_mime_part_set_encoding (
                        CAMEL_MIME_PART (context->message),
                        context->plain_encoding);
diff --git a/src/libemail-engine/e-mail-folder-utils.c b/src/libemail-engine/e-mail-folder-utils.c
index 505b9f4b6f..5f8922824d 100644
--- a/src/libemail-engine/e-mail-folder-utils.c
+++ b/src/libemail-engine/e-mail-folder-utils.c
@@ -107,10 +107,12 @@ e_mail_folder_append_message_sync (CamelFolder *folder,
                full_display_name ? full_display_name : camel_folder_get_display_name (folder));
        g_free (full_display_name);
 
-       if (camel_medium_get_header (medium, "User-Agent") == NULL)
-               camel_medium_set_header (medium, "User-Agent", USER_AGENT);
+       if (!camel_medium_get_header (medium, "X-Evolution-Is-Redirect")) {
+               if (camel_medium_get_header (medium, "User-Agent") == NULL)
+                       camel_medium_set_header (medium, "User-Agent", USER_AGENT);
 
-       camel_mime_message_set_date (message, CAMEL_MESSAGE_DATE_CURRENT, 0);
+               camel_mime_message_set_date (message, CAMEL_MESSAGE_DATE_CURRENT, 0);
+       }
 
        success = camel_folder_append_message_sync (
                folder, message, info, appended_uid, cancellable, error);
diff --git a/src/libemail-engine/e-mail-session-utils.c b/src/libemail-engine/e-mail-session-utils.c
index 3aaf924e0b..7be43cb85c 100644
--- a/src/libemail-engine/e-mail-session-utils.c
+++ b/src/libemail-engine/e-mail-session-utils.c
@@ -818,7 +818,8 @@ e_mail_session_send_to (EMailSession *session,
 
        medium = CAMEL_MEDIUM (message);
 
-       camel_medium_set_header (medium, "User-Agent", USER_AGENT);
+       if (!camel_medium_get_header (medium, "X-Evolution-Is-Redirect"))
+               camel_medium_set_header (medium, "User-Agent", USER_AGENT);
 
        /* Do this before removing "X-Evolution" headers. */
        transport = e_mail_session_ref_transport_for_message (
diff --git a/src/libemail-engine/mail-ops.c b/src/libemail-engine/mail-ops.c
index 028272ed01..aefa2ae6dd 100644
--- a/src/libemail-engine/mail-ops.c
+++ b/src/libemail-engine/mail-ops.c
@@ -598,7 +598,8 @@ mail_send_message (struct _send_queue_msg *m,
        if (!message)
                return;
 
-       camel_medium_set_header (CAMEL_MEDIUM (message), "User-Agent", USER_AGENT);
+       if (!camel_medium_get_header (CAMEL_MEDIUM (message), "X-Evolution-Is-Redirect"))
+               camel_medium_set_header (CAMEL_MEDIUM (message), "User-Agent", USER_AGENT);
 
        /* Do this before removing "X-Evolution" headers. */
        service = e_mail_session_ref_transport_for_message (