path: root/mail/mail-format.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*
 * Authors:
 *  Matt Loper <matt@helixcode.com>
 *  Dan Winship <danw@helixcode.com>
 *
 *  Copyright 2000, Helix Code, Inc. (http://www.helixcode.com)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <ctype.h>    /* for isprint */
#include <string.h>   /* for strstr  */
#include <fcntl.h>

#include <liboaf/liboaf.h>
#include <libgnome/libgnome.h>
#include <libgnomevfs/gnome-vfs-mime-info.h>
#include <libgnomevfs/gnome-vfs-mime-handlers.h>
#include <gal/widgets/e-unicode.h>

#include <camel/camel-mime-utils.h>
#include <camel/camel-pgp-mime.h>
#include <shell/e-setup.h>
#include <e-util/e-html-utils.h>

#include "mail.h"
#include "mail-tools.h"
#include "mail-display.h"
#include "mail-mt.h"
#include "mail-crypto.h"

static char *get_data_wrapper_text (CamelDataWrapper *data);

static char *try_inline_pgp (char *start, MailDisplay *md);
static char *try_inline_pgp_sig (char *start, MailDisplay *md);
static char *try_uudecoding (char *start, MailDisplay *md);
static char *try_inline_binhex (char *start, MailDisplay *md);

static gboolean handle_text_plain            (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_text_plain_flowed     (char *text,
                          MailDisplay *md);
static gboolean handle_text_enriched         (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_text_html             (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_image                 (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_mixed       (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_related     (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_alternative (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_appledouble (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_encrypted   (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_multipart_signed      (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_message_rfc822        (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);
static gboolean handle_message_external_body (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);

static gboolean handle_via_bonobo            (CamelMimePart *part,
                          const char *mime_type,
                          MailDisplay *md);

/* writes the header info for a mime message into an html stream */
static void write_headers (CamelMimeMessage *message, MailDisplay *md);

/* dispatch html printing via mimetype */
static gboolean call_handler_function (CamelMimePart *part, MailDisplay *md);

static void
free_url (gpointer key, gpointer value, gpointer data)
{
    g_free (key);
}

static void
free_urls (gpointer urls)
{
    g_hash_table_foreach (urls, free_url, NULL);
    g_hash_table_destroy (urls);
}

static char *
add_url (char *url, gpointer data, MailDisplay *md)
{
    GHashTable *urls;
    gpointer old_key, old_value;

    urls = g_datalist_get_data (md->data, "urls");
    g_return_val_if_fail (urls != NULL, NULL);
    
    if (g_hash_table_lookup_extended (urls, url, &old_key, &old_value)) {
        g_free (url);
        url = old_key;
    }
    g_hash_table_insert (urls, url, data);
    return url;
}

/**
 * mail_format_mime_message: 
 * @mime_message: the input mime message
 * @md: the MailDisplay to render into
 *
 * Writes a CamelMimeMessage out into a MailDisplay
 **/
void
mail_format_mime_message (CamelMimeMessage *mime_message, MailDisplay *md)
{
    GHashTable *urls;

    g_return_if_fail (CAMEL_IS_MIME_MESSAGE (mime_message));

    urls = g_datalist_get_data (md->data, "urls");
    if (!urls) {
        urls = g_hash_table_new (g_str_hash, g_str_equal);
        g_datalist_set_data_full (md->data, "urls", urls,
                      free_urls);
    }
    
    write_headers (mime_message, md);
    call_handler_function (CAMEL_MIME_PART (mime_message), md);
}


/**
 * mail_format_raw_message: 
 * @mime_message: the input mime message
 * @md: the MailDisplay to render into
 *
 * Writes a CamelMimeMessage source out into a MailDisplay
 **/
void
mail_format_raw_message (CamelMimeMessage *mime_message, MailDisplay *md)
{
    gchar *text;
    
    g_return_if_fail (CAMEL_IS_MIME_MESSAGE (mime_message));
    
    text = get_data_wrapper_text (CAMEL_DATA_WRAPPER (mime_message));
    mail_text_write (md->html, md->stream, "%s", text ? text : "");
    g_free (text);
}

static const char *
get_cid (CamelMimePart *part, MailDisplay *md)
{
    GHashTable *urls;
    char *cid;
    gpointer orig_name, value;
    static int fake_cid_counter = 0;

    urls = g_datalist_get_data (md->data, "urls");

    /* If we have a real Content-ID, use it. If we don't,
     * make a (syntactically invalid, unique) fake one.
     */
    if (camel_mime_part_get_content_id (part)) {
        cid = g_strdup_printf ("cid:%s",
                       camel_mime_part_get_content_id (part));
    } else
        cid = g_strdup_printf ("cid:@@@%d", fake_cid_counter++);

    if (g_hash_table_lookup_extended (urls, cid, &orig_name, &value)) {
        g_free (cid);
        return orig_name;
    } else
        g_hash_table_insert (urls, cid, part);

    return cid;
}

static const char *
get_url_for_icon (const char *icon_name, MailDisplay *md)
{
    static GHashTable *icons;
    char *icon_path, buf[1024], *url;
    GByteArray *ba;

    if (!icons)
        icons = g_hash_table_new (g_str_hash, g_str_equal);

    if (*icon_name == '/')
        icon_path = g_strdup (icon_name);
    else {
        icon_path = gnome_pixmap_file (icon_name);
        if (!icon_path)
            return "file:///dev/null";
    }

    ba = g_hash_table_lookup (icons, icon_path);
    if (!ba) {
        int fd, nread;

        fd = open (icon_path, O_RDONLY);
        if (fd == -1) {
            g_free (icon_path);
            return "file:///dev/null";
        }

        ba = g_byte_array_new ();

        while (1) {
            nread = read (fd, buf, sizeof (buf));
            if (nread < 1)
                break;
            g_byte_array_append (ba, buf, nread);
        }
        close (fd);

        /* FIXME: these aren't freed. */
        g_hash_table_insert (icons, g_strdup (icon_path), ba);
    }
    g_free (icon_path);

    url = g_strdup_printf ("x-evolution-data:%p", ba);
    return add_url (url, ba, md);
}


static GHashTable *mime_handler_table, *mime_function_table;

static void
setup_mime_tables (void)
{
    mime_handler_table = g_hash_table_new (g_str_hash, g_str_equal);
    mime_function_table = g_hash_table_new (g_str_hash, g_str_equal);

    g_hash_table_insert (mime_function_table, "text/plain",
                 handle_text_plain);
    g_hash_table_insert (mime_function_table, "text/richtext",
                 handle_text_enriched);
    g_hash_table_insert (mime_function_table, "text/enriched",
                 handle_text_enriched);
    g_hash_table_insert (mime_function_table, "text/html",
                 handle_text_html);

    g_hash_table_insert (mime_function_table, "image/gif",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/jpeg",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/png",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-png",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/tiff",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-bmp",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/bmp",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-cmu-raster",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-ico",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-portable-anymap",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-portable-bitmap",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-portable-graymap",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-portable-pixmap",
                 handle_image);
    g_hash_table_insert (mime_function_table, "image/x-xpixmap",
                 handle_image);

    g_hash_table_insert (mime_function_table, "message/rfc822",
                 handle_message_rfc822);
    g_hash_table_insert (mime_function_table, "message/news",
                 handle_message_rfc822);
    g_hash_table_insert (mime_function_table, "message/external-body",
                 handle_message_external_body);

    g_hash_table_insert (mime_function_table, "multipart/alternative",
                 handle_multipart_alternative);
    g_hash_table_insert (mime_function_table, "multipart/related",
                 handle_multipart_related);
    g_hash_table_insert (mime_function_table, "multipart/mixed",
                 handle_multipart_mixed);
    g_hash_table_insert (mime_function_table, "multipart/appledouble",
                 handle_multipart_appledouble);
    g_hash_table_insert (mime_function_table, "multipart/encrypted",
                 handle_multipart_encrypted);
    g_hash_table_insert (mime_function_table, "multipart/signed",
                 handle_multipart_signed);

    /* RFC 2046 says unrecognized text subtypes can be treated
     * as text/plain (as long as you recognize the character set),
     * and unrecognized multipart subtypes as multipart/mixed.
     */
    g_hash_table_insert (mime_function_table, "text/*",
                 handle_text_plain);
    g_hash_table_insert (mime_function_table, "multipart/*",
                 handle_multipart_mixed);
}

static gboolean
component_supports (OAF_ServerInfo *component, const char *mime_type)
{
    OAF_Property *prop;
    CORBA_sequence_CORBA_string stringv;
    int i;

    prop = oaf_server_info_prop_find (component,
                      "bonobo:supported_mime_types");
    if (!prop || prop->v._d != OAF_P_STRINGV)
        return FALSE;

    stringv = prop->v._u.value_stringv;
    for (i = 0; i < stringv._length; i++) {
        if (!g_strcasecmp (mime_type, stringv._buffer[i]))
            return TRUE;
    }
    return FALSE;
}

/**
 * mail_lookup_handler:
 * @mime_type: a MIME type
 *
 * Looks up the MIME type in its own tables and GNOME-VFS's and returns
 * a MailMimeHandler structure detailing the component, application,
 * and built-in handlers (if any) for that MIME type. (If the component
 * is non-%NULL, the built-in handler will always be handle_via_bonobo().)
 * The MailMimeHandler's @generic field is set if the match was for the
 * MIME supertype rather than the exact type.
 *
 * Return value: a MailMimeHandler (which should not be freed), or %NULL
 * if no handlers are available.
 **/
MailMimeHandler *
mail_lookup_handler (const char *mime_type)
{
    MailMimeHandler *handler;
    char *mime_type_main;

    if (mime_handler_table == NULL)
        setup_mime_tables ();

    /* See if we've already found it. */
    handler = g_hash_table_lookup (mime_handler_table, mime_type);
    if (handler)
        return handler;

    /* No. Create a new one and look up application and full type
     * handler. If we find a builtin, create the handler and
     * register it.
     */
    handler = g_new0 (MailMimeHandler, 1);
    handler->application =
        gnome_vfs_mime_get_default_application (mime_type);
    handler->builtin =
        g_hash_table_lookup (mime_function_table, mime_type);

    if (handler->builtin) {
        handler->generic = FALSE;
        goto reg;
    }

    /* Try for a exact component match. */
    handler->component = gnome_vfs_mime_get_default_component (mime_type);
    if (handler->component &&
        component_supports (handler->component, mime_type)) {
        handler->generic = FALSE;
        handler->builtin = handle_via_bonobo;
        goto reg;
    }

    /* Try for a generic builtin match. */
    mime_type_main = g_strdup_printf ("%.*s/*",
                      (int)strcspn (mime_type, "/"),
                      mime_type);
    handler->builtin = g_hash_table_lookup (mime_function_table,
                        mime_type_main);
    g_free (mime_type_main);

    if (handler->builtin) {
        handler->generic = TRUE;
        if (handler->component) {
            CORBA_free (handler->component);
            handler->component = NULL;
        }
        goto reg;
    }

    /* Try for a generic component match. */
    if (handler->component) {
        handler->generic = TRUE;
        handler->builtin = handle_via_bonobo;
        goto reg;
    }

    /* If we at least got an application, use that. */
    if (handler->application) {
        handler->generic = TRUE;
        goto reg;
    }

    /* Nada. */
    g_free (handler);
    return NULL;

 reg:
    g_hash_table_insert (mime_handler_table, g_strdup (mime_type),
                 handler);
    return handler;
}

/* An "anonymous" MIME part is one that we shouldn't call attention
 * to the existence of, but simply display.
 */
static gboolean
is_anonymous (CamelMimePart *part, const char *mime_type)
{
    if (!g_strncasecmp (mime_type, "multipart/", 10) ||
        !g_strncasecmp (mime_type, "message/", 8))
        return TRUE;

    if (!g_strncasecmp (mime_type, "text/", 5) &&
        !camel_mime_part_get_filename (part))
        return TRUE;

    return FALSE;
}

/**
 * mail_part_is_inline:
 * @part: a CamelMimePart
 *
 * Return value: whether or not the part should/will be displayed inline.
 **/
gboolean
mail_part_is_inline (CamelMimePart *part)
{
    const char *disposition;
    CamelContentType *content_type;

    /* If it has an explicit disposition, return that. */
    disposition = camel_mime_part_get_disposition (part);
    if (disposition)
        return g_strcasecmp (disposition, "inline") == 0;

    /* Certain types should default to inline. FIXME: this should
     * be customizable.
     */
    content_type = camel_mime_part_get_content_type (part);
    if (!header_content_type_is (content_type, "message", "*"))
        return TRUE;

    /* Otherwise, display it inline if it's "anonymous", and
     * as an attachment otherwise.
     */
    return is_anonymous (part, header_content_type_simple (content_type));
}

static void
attachment_header (CamelMimePart *part, const char *mime_type,
           gboolean is_inline, MailDisplay *md)
{
    const char *info;
    char *htmlinfo;

    /* No header for anonymous inline parts. */
    if (is_inline && is_anonymous (part, mime_type))
        return;

    /* Start the table, create the pop-up object. */
    mail_html_write (md->html, md->stream, "<table><tr><td>"
             "<object classid=\"popup:%s\" type=\"%s\">"
             "</object></td><td><font size=-1>",
             get_cid (part, md), mime_type);

    /* Write the MIME type */
    info = gnome_vfs_mime_get_value (mime_type, "description");
    htmlinfo = e_text_to_html (info ? info : mime_type, 0);
    mail_html_write (md->html, md->stream, _("%s attachment"), htmlinfo);
    g_free (htmlinfo);

    /* Write the name, if we have it. */
    info = camel_mime_part_get_filename (part);
    if (info) {
        htmlinfo = e_text_to_html (info, 0);
        mail_html_write (md->html, md->stream, " (%s)", htmlinfo);
        g_free (htmlinfo);
    }

    /* Write a description, if we have one. */
    info = camel_mime_part_get_description (part);
    if (info) {
        htmlinfo = e_text_to_html (info, E_TEXT_TO_HTML_CONVERT_URLS);
        mail_html_write (md->html, md->stream, ", \"%s\"", htmlinfo);
        g_free (htmlinfo);
    }

#if 0
    /* Describe the click action, if any. */
    if (action) {
        mail_html_write (md->html, md->stream,
                 "<br>Click on the icon to %s.", action);
    }
#endif

    mail_html_write (md->html, md->stream, "</font></td></tr></table>");
}

static gboolean
call_handler_function (CamelMimePart *part, MailDisplay *md)
{
    CamelDataWrapper *wrapper;
    char *mime_type;
    MailMimeHandler *handler;
    gboolean output, is_inline;

    wrapper = camel_medium_get_content_object (CAMEL_MEDIUM (part));

    if (CAMEL_IS_MULTIPART (wrapper) &&
        camel_multipart_get_number (CAMEL_MULTIPART (wrapper)) == 0) {
        mail_error_write (md->html, md->stream, _("Could not parse MIME message. Displaying as source."));
        if (mail_content_loaded (wrapper, md))
            handle_text_plain (part, "text/plain", md);
        return TRUE;
    }

    mime_type = camel_data_wrapper_get_mime_type (wrapper);
    g_strdown (mime_type);

    handler = mail_lookup_handler (mime_type);
    if (!handler) {
        char *id_type;

        id_type = mail_identify_mime_part (part, md);
        if (id_type) {
            g_free (mime_type);
            mime_type = id_type;
            handler = mail_lookup_handler (id_type);
        }
    }

    is_inline = mail_part_is_inline (part);
    attachment_header (part, mime_type, is_inline, md);
    if (handler && handler->builtin && is_inline &&
        mail_content_loaded (wrapper, md))
        output = (*handler->builtin) (part, mime_type, md);
    else
        output = TRUE;

    g_free (mime_type);
    return output;
}

/* flags for write_field_to_stream */
enum {
    WRITE_BOLD=1,
};

static void
write_field_row_begin (const char *description, gint flags, GtkHTML *html, GtkHTMLStream *stream)
{
    char *encoded_desc;
    int bold = (flags & WRITE_BOLD) == WRITE_BOLD;

    encoded_desc = e_utf8_from_gtk_string (GTK_WIDGET (html), description);

    mail_html_write (html, stream, "<tr><%s align=\"right\" valign=\"top\">%s</%s>",
             bold ? "th" : "td", encoded_desc, bold ? "th" : "td");

    g_free (encoded_desc);
}

static void
write_date (CamelMimeMessage *message, int flags, GtkHTML *html, GtkHTMLStream *stream)
{
    char *datestr;
    time_t date;
    int offset;
    
    write_field_row_begin (_("Date:"), flags, html, stream);
    
    date = camel_mime_message_get_date (message, &offset);
    datestr = header_format_date (date, offset);
    
    mail_html_write (html, stream, "<td>%s</td> </tr>", datestr);
    
    g_free (datestr);
}

static void
write_subject (const char *subject, int flags, GtkHTML *html, GtkHTMLStream *stream)
{
    char *encoded_subj;

    if (subject)
        encoded_subj = e_text_to_html (subject, E_TEXT_TO_HTML_CONVERT_NL | E_TEXT_TO_HTML_CONVERT_URLS);
    else
        encoded_subj = "";

    write_field_row_begin (_("Subject:"), flags, html, stream);

    mail_html_write (html, stream, "<td>%s</td> </tr>", encoded_subj);

    if (subject)
        g_free (encoded_subj);
}

static void
write_address(MailDisplay *md, const CamelInternetAddress *addr, const char *field_name, int flags)
{
    const char *name, *email;
    gboolean name_set, mail_set;
    gint i;

    if (addr == NULL || !camel_internet_address_get (addr, 0, NULL, NULL))
        return;

    write_field_row_begin (field_name, flags, md->html, md->stream);

    i = 0;
    while (camel_internet_address_get (addr, i, &name, &email)) {
        
        if ((name && *name) || (email && *email)) {

            /* we need these <B> </B> to separate HTMLText objects */
            mail_html_write (md->html, md->stream, i ? ",<B> </B> " : "<td>");
            mail_html_write (md->html, md->stream, " ");

            name_set = mail_set = FALSE;
            if (name && *name) {
                mail_html_write (md->html, md->stream,
                         "<!--+GtkHTML:<DATA class=\"Text\" key=\"name\" value=\"%s\">-->",
                         name);
                name_set = TRUE;
            }

            if (email && *email) {
                mail_html_write (md->html, md->stream,
                         "<!--+GtkHTML:<DATA class=\"Text\" key=\"email\" value=\"%s\">-->",
                         email);
                mail_set = TRUE;
            }

            if (name && *name)
                mail_html_write (md->html, md->stream, "%s ", name);
            if (email && *email)
                mail_html_write (md->html, md->stream, "%s%s%s",
                         name && *name ? "&lt;" : "",
                         email,
                         name && *name ? "&gt;" : "");
            if (name_set)
                mail_html_write (md->html, md->stream,
                         "<!--+GtkHTML:<DATA class=\"Text\" clear=\"name\">-->");
            if (mail_set)
                mail_html_write (md->html, md->stream,
                         "<!--+GtkHTML:<DATA class=\"Text\" clear=\"email\">-->");
        }
        
        ++i;
    }
    mail_html_write (md->html, md->stream, "</td></tr>"); /* Finish up the table row */
}


static void
write_headers (CamelMimeMessage *message, MailDisplay *md)
{
    mail_html_write (md->html, md->stream,
             "<font color=\"#000000\">"
             "<table bgcolor=\"#000000\" width=\"100%%\" "
             "cellspacing=0 cellpadding=1><tr><td>"
             "<table bgcolor=\"#EEEEEE\" width=\"100%%\" cellpadding=0 cellspacing=0>"
             "<tr><td><table>\n");
    
    write_address(md, camel_mime_message_get_from(message),
              _("From:"), WRITE_BOLD);
    write_address(md, camel_mime_message_get_reply_to(message),
              _("Reply-To:"), 0);
    write_address(md, camel_mime_message_get_recipients(message, CAMEL_RECIPIENT_TYPE_TO),
              _("To:"), WRITE_BOLD);
    write_address(md, camel_mime_message_get_recipients(message, CAMEL_RECIPIENT_TYPE_CC),
              _("Cc:"), WRITE_BOLD);
    
    write_subject (camel_mime_message_get_subject (message), WRITE_BOLD, md->html, md->stream);
    
    write_date (message,WRITE_BOLD, md->html, md->stream);
    
    mail_html_write (md->html, md->stream,
             "</table></td></tr></table></td></tr></table></font>");
}

struct _load_content_msg {
    struct _mail_msg msg;

    MailDisplay *display;
    CamelMimeMessage *message;
    CamelDataWrapper *wrapper;
};

static char *
load_content_desc (struct _mail_msg *mm, int done)
{
    return g_strdup (_("Loading message content"));
}

static void
load_content_load (struct _mail_msg *mm)
{
    struct _load_content_msg *m = (struct _load_content_msg *)mm;
    CamelStream *memstream;

    memstream = camel_stream_mem_new ();
    camel_data_wrapper_write_to_stream (m->wrapper, memstream);
    camel_object_unref (CAMEL_OBJECT (memstream));
}

static void
load_content_loaded (struct _mail_msg *mm)
{
    struct _load_content_msg *m = (struct _load_content_msg *)mm;

    if (m->display->current_message == m->message)
        mail_display_queue_redisplay (m->display);
}

static void
load_content_free (struct _mail_msg *mm)
{
    struct _load_content_msg *m = (struct _load_content_msg *)mm;

    gtk_object_unref (GTK_OBJECT (m->display));
    camel_object_unref (CAMEL_OBJECT (m->wrapper));
    camel_object_unref (CAMEL_OBJECT (m->message));
}

static struct _mail_msg_op load_content_op = {
    load_content_desc,
    load_content_load,
    load_content_loaded,
    load_content_free,
};

gboolean
mail_content_loaded (CamelDataWrapper *wrapper, MailDisplay *md)
{
    struct _load_content_msg *m;
    GHashTable *loading;

    if (!camel_data_wrapper_is_offline (wrapper))
        return TRUE;

    loading = g_datalist_get_data (md->data, "loading");
    if (loading) {
        if (g_hash_table_lookup (loading, wrapper))
            return FALSE;
    } else {
        loading = g_hash_table_new (NULL, NULL);
        g_datalist_set_data_full (md->data, "loading", loading,
                      (GDestroyNotify)g_hash_table_destroy);
    }
    g_hash_table_insert (loading, wrapper, GINT_TO_POINTER (1));    

    m = mail_msg_new (&load_content_op, NULL, sizeof (*m));
    m->display = md;
    gtk_object_ref (GTK_OBJECT (m->display));
    m->message = md->current_message;
    camel_object_ref (CAMEL_OBJECT (m->message));
    m->wrapper = wrapper;
    camel_object_ref (CAMEL_OBJECT (m->wrapper));

    e_thread_put (mail_thread_queued, (EMsg *)m);
    return FALSE;
}

/* Return the contents of a data wrapper, or %NULL if it contains only
 * whitespace.
 */
static char *
get_data_wrapper_text (CamelDataWrapper *wrapper)
{
    CamelStream *memstream;
    GByteArray *ba;
    char *text, *end;

    memstream = camel_stream_mem_new ();
    ba = g_byte_array_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (memstream), ba);
    camel_data_wrapper_write_to_stream (wrapper, memstream);
    camel_object_unref (CAMEL_OBJECT (memstream));

    for (text = ba->data, end = text + ba->len; text < end; text++) {
        if (!isspace ((unsigned char)*text))
            break;
    }

    if (text >= end) {
        g_byte_array_free (ba, TRUE);
        return NULL;
    }

    g_byte_array_append (ba, "", 1);
    text = ba->data;
    g_byte_array_free (ba, FALSE);
    return text;
}

/*----------------------------------------------------------------------*
 *                     Mime handling functions
 *----------------------------------------------------------------------*/

struct {
    char *start;
    char * (*handler) (char *start, MailDisplay *md);
} text_specials[] = {
    { "-----BEGIN PGP MESSAGE-----\n", try_inline_pgp },
    { "-----BEGIN PGP SIGNED MESSAGE-----\n", try_inline_pgp_sig },
    { "begin ", try_uudecoding },
    { "(This file must be converted with BinHex 4.0)\n", try_inline_binhex }
};
#define NSPECIALS (sizeof (text_specials) / sizeof (*text_specials))

static gboolean
handle_text_plain (CamelMimePart *part, const char *mime_type,
           MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    char *text, *p, *start;
    CamelContentType *type;
    gboolean check_specials;
    const char *format;
    int i;

    text = get_data_wrapper_text (wrapper);
    if (!text)
        return FALSE;

    /* Check for RFC 2646 flowed text. */
    type = camel_mime_part_get_content_type (part);
    format = header_content_type_param (type, "format");
    if (format && !g_strcasecmp (format, "flowed"))
        return handle_text_plain_flowed (text, md);

    mail_html_write (md->html, md->stream, "\n<!-- text/plain -->\n<font size=\"-3\">&nbsp</font><br>\n");

    /* Only look for binhex and stuff if this is real text/plain.
     * (and not, say, application/mac-binhex40 that mail-identify
     * has decided to call text/plain because it starts with English
     * text...)
     */
    check_specials = g_strcasecmp (mime_type, "text/plain") != 0;

    p = text;
    while (p && check_specials) {
        /* Look for special cases. */
        for (i = 0; i < NSPECIALS; i++) {
            start = strstr (p, text_specials[i].start);
            if (start && (start == p || start[-1] == '\n'))
                break;
        }
        if (!start)
            break;

        /* Deal with special case */
        if (start != p) {
            /* the %.*s thing just grabs upto start-p chars; go read ANSI C */
            mail_text_write (md->html, md->stream, "%.*s", start-p, p);
        }
        p = text_specials[i].handler (start, md);
        if (p == start) {
            /* Oops. That failed. Output this line normally and
             * skip over it.
             */
            p = strchr (start, '\n');
            if (!p++)
                break;
            mail_text_write (md->html, md->stream, "%.*s", p-start, start);
        } else if (p)
            mail_html_write (md->html, md->stream, "<hr>");
    }
    /* Finish up (or do the whole thing if there were no specials). */
    if (p)
        mail_text_write (md->html, md->stream, "%s", p);

    g_free (text);
    return TRUE;
}

static gboolean
handle_text_plain_flowed (char *buf, MailDisplay *md)
{
    char *text, *line, *eol, *p;
    int prevquoting = 0, quoting, len;
    gboolean br_pending = FALSE;

    mail_html_write (md->html, md->stream,
             "\n<!-- text/plain, flowed -->\n<font size=\"-3\">&nbsp</font><br>\n<tt>\n");

    for (line = buf; *line; line = eol + 1) {
        /* Process next line */
        eol = strchr (line, '\n');
        if (eol)
            *eol = '\0';

        quoting = 0;
        for (p = line; *p == '>'; p++)
            quoting++;
        if (quoting != prevquoting) {
            mail_html_write (md->html, md->stream, "%s\n",
                     prevquoting == 0 ? "<i>\n" : "");
            while (quoting > prevquoting) {
                mail_html_write (md->html, md->stream,
                         "<blockquote>");
                prevquoting++;
            }
            while (quoting < prevquoting) {
                mail_html_write (md->html, md->stream,
                         "</blockquote>");
                prevquoting--;
            }
            mail_html_write (md->html, md->stream, "%s\n",
                     prevquoting == 0 ? "</i>\n" : "");
        } else if (br_pending) {
            mail_html_write (md->html, md->stream, "<br>\n");
            br_pending = FALSE;
        }

        if (*p == ' ')
            p++;

        /* replace '<' with '&lt;', etc. */
        text = e_text_to_html (p, E_TEXT_TO_HTML_CONVERT_SPACES |
                       E_TEXT_TO_HTML_CONVERT_URLS);
        if (text && *text)
            mail_html_write (md->html, md->stream, "%s", text);
        g_free (text);

        len = strlen (p);
        if (len == 0 || p[len - 1] != ' ' || !strcmp (p, "-- "))
            br_pending = TRUE;

        if (!eol)
            break;
    }
    g_free (buf);

    mail_html_write (md->html, md->stream, "</tt>\n");
    return TRUE;
}

static CamelMimePart *
fake_mime_part_from_data (const char *data, int len, const char *type)
{
    CamelStream *memstream;
    CamelDataWrapper *wrapper;
    CamelMimePart *part;

    memstream = camel_stream_mem_new_with_buffer (data, len);
    wrapper = camel_data_wrapper_new ();
    camel_data_wrapper_construct_from_stream (wrapper, memstream);
    camel_data_wrapper_set_mime_type (wrapper, type);
    camel_object_unref (CAMEL_OBJECT (memstream));
    part = camel_mime_part_new ();
    camel_medium_set_content_object (CAMEL_MEDIUM (part), wrapper);
    camel_object_unref (CAMEL_OBJECT (wrapper));
    camel_mime_part_set_disposition (part, "inline");
    return part;
}

static void
destroy_part (CamelObject *root, gpointer event_data, gpointer user_data)
{
    camel_object_unref (user_data);
}

static void
decode_pgp (CamelStream *ciphertext, CamelStream *plaintext, MailDisplay *md)
{
    CamelException ex;
    
    camel_exception_init (&ex);
    
    /* FIXME: multipart parts */
    /* another FIXME: this doesn't have to return plaintext you realize... */
    if (g_datalist_get_data (md->data, "show_pgp")) {
        CamelPgpContext *ctx;
        
        ctx = camel_pgp_context_new (session, mail_config_get_pgp_type (),
                         mail_config_get_pgp_path ());
        
        camel_pgp_decrypt (ctx, ciphertext, plaintext, &ex);
        camel_object_unref (CAMEL_OBJECT (ctx));
        camel_stream_reset (plaintext);
        
        if (!camel_exception_is_set (&ex))
            return;
    }
    
    mail_html_write (md->html, md->stream,
             "<table><tr valign=top><td>"
             "<a href=\"x-evolution-decode-pgp:\">"
             "<img src=\"%s\"></a></td><td>",
             get_url_for_icon ("gnome-lockscreen.png", md));

    if (camel_exception_is_set (&ex)) {
        mail_html_write (md->html, md->stream, "%s<br><br>\n",
                 _("Encrypted message not displayed"));
        mail_error_write (md->html, md->stream,
                  camel_exception_get_description (&ex));
        camel_exception_clear (&ex);
    } else {
        mail_html_write (md->html, md->stream, "%s<br><br>\n%s",
                 _("Encrypted message"),
                 _("Click icon to decrypt."));
    }

    mail_html_write (md->html, md->stream, "</td></tr></table>");
}

static char *
try_inline_pgp (char *start, MailDisplay *md)
{
    CamelStream *ciphertext, *plaintext;
    GByteArray *buffer;
    char *end;
    
    end = strstr (start, "-----END PGP MESSAGE-----");
    if (!end)
        return start;
    
    end += strlen ("-----END PGP MESSAGE-----") - 1;
    
    mail_html_write (md->html, md->stream, "<hr>");
    
    /* FIXME: uhm, pgp decrypted data doesn't have to be plaintext
     * however, I suppose that since it was 'inline', it probably is */
    
    ciphertext = camel_stream_mem_new ();
    camel_stream_write (ciphertext, start, end - start);
    camel_stream_reset (ciphertext);
    
    plaintext = camel_stream_mem_new ();
    decode_pgp (ciphertext, plaintext, md);
    camel_object_unref (CAMEL_OBJECT (ciphertext));
    
    buffer = CAMEL_STREAM_MEM (plaintext)->buffer;
    if (buffer && buffer->len) {
        mail_html_write (md->html, md->stream,
                 "<table width=\"100%%\" border=2 "
                 "cellpadding=4><tr><td>");
        mail_text_write (md->html, md->stream, "%.*s", buffer->len, buffer->data);
        mail_html_write (md->html, md->stream, "</td></tr></table>");
    }
    
    camel_object_unref (CAMEL_OBJECT (plaintext));
    
    return end;
}

static char *
try_inline_pgp_sig (char *start, MailDisplay *md)
{
    CamelPgpContext *context;
    CamelStream *ciphertext;
    CamelPgpValidity *valid;
    CamelException *ex;
    char *end;
    
    end = strstr (start, "-----END PGP SIGNATURE-----");
    if (!end)
        return start;
    
    end += strlen ("-----END PGP SIGNATURE-----");
    
    mail_html_write (md->html, md->stream, "<hr>");
    
    context = camel_pgp_context_new (session, mail_config_get_pgp_type (),
                     mail_config_get_pgp_path ());
    
    ciphertext = camel_stream_mem_new ();
    camel_stream_write (ciphertext, start, end - start);
    camel_stream_reset (ciphertext);
    
    ex = camel_exception_new ();
    valid = camel_pgp_verify (context, ciphertext, NULL, ex);
    camel_object_unref (CAMEL_OBJECT (ciphertext));
    camel_object_unref (CAMEL_OBJECT (context));
    
    mail_text_write (md->html, md->stream, "%.*s", end - start, start);
    
    /* Now display the "seal-of-authenticity" or something... */
    if (valid && camel_pgp_validity_get_valid (valid)) {
        mail_html_write (md->html, md->stream,
                 "<hr>\n<table><tr valign=top>"
                 "<td><img src=\"%s\"></td>"
                 "<td><font size=-1>%s<br><br>",
                 get_url_for_icon ("wax-seal2.png", md),
                 _("This message is digitally signed and "
                   "has been found to be authentic."));
    } else {
        mail_html_write (md->html, md->stream,
                 "<hr>\n<table><tr valign=top>"
                 "<td><img src=\"%s\"></td>"
                 "<td><font size=-1>%s<br><br>",
                 get_url_for_icon ("wax-seal-broken.png", md),
                 _("This message is digitally signed but can "
                   "not be proven to be authentic."));
    }
    
    if (valid && camel_pgp_validity_get_description (valid)) {
        mail_error_write (md->html, md->stream,
                  camel_pgp_validity_get_description (valid));
        mail_html_write (md->html, md->stream, "<br><br>");
    }
    
    mail_html_write (md->html, md->stream, "</font></td></table>");
        
    camel_exception_free (ex);
    camel_pgp_validity_free (valid);
    
    return end;
}

static char *
try_uudecoding (char *start, MailDisplay *md)
{
    int mode, len, state = 0;
    char *filename, *estart, *p, *out, uulen = 0;
    guint32 save = 0;
    CamelMimePart *part;

    /* Make sure it's a real uudecode begin line:
     * begin [0-7]+ .*
     */
    mode = strtoul (start + 6, &p, 8);
    if (p == start + 6 || *p != ' ')
        return start;
    estart = strchr (start, '\n');
    if (!estart)
        return start;

    while (isspace ((unsigned char)*p))
        p++;
    filename = g_strndup (p, estart++ - p);

    /* Make sure there's an end line. */
    p = strstr (p, "\nend\n");
    if (!p) {
        g_free (filename);
        return start;
    }

    out = g_malloc (p - estart);
    len = uudecode_step (estart, p - estart, out, &state, &save, &uulen);

    part = fake_mime_part_from_data (out, len, "application/octet-stream");
    g_free (out);
    camel_mime_part_set_filename (part, filename);
    g_free (filename);
    camel_object_hook_event (CAMEL_OBJECT (md->current_message),
                 "finalize", destroy_part, part);

    mail_html_write (md->html, md->stream, "<hr>");
    call_handler_function (part, md);

    return p + 4;
}

static char *
try_inline_binhex (char *start, MailDisplay *md)
{
    char *p;
    CamelMimePart *part;

    /* Find data start. */
    p = strstr (start, "\n:");
    if (!p)
        return start;

    /* And data end. */
    p = strchr (p + 2, ':');
    if (!p || (*(p + 1) != '\n' && *(p + 1) != '\0'))
        return start;
    p += 2;

    part = fake_mime_part_from_data (start, p - start,
                     "application/mac-binhex40");
    camel_object_hook_event (CAMEL_OBJECT (md->current_message),
                 "finalize", destroy_part, part);

    mail_html_write (md->html, md->stream, "<hr>");
    call_handler_function (part, md);

    return p;
}

static void
free_byte_array (CamelObject *obj, gpointer event_data, gpointer user_data)
{
    /* We don't have to do a forward event here right now */
    g_byte_array_free (user_data, TRUE);
}

/* text/enriched (RFC 1896) or text/richtext (included in RFC 1341) */
static gboolean
handle_text_enriched (CamelMimePart *part, const char *mime_type,
              MailDisplay *md)
{
    static GHashTable *translations = NULL;
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    GString *string;
    GByteArray *ba;
    char *text, *p, *xed;
    int len, nofill = 0;
    gboolean enriched;

    if (!translations) {
        translations = g_hash_table_new (g_strcase_hash,
                         g_strcase_equal);
        g_hash_table_insert (translations, "bold", "<b>");
        g_hash_table_insert (translations, "/bold", "</b>");
        g_hash_table_insert (translations, "italic", "<i>");
        g_hash_table_insert (translations, "/italic", "</i>");
        g_hash_table_insert (translations, "fixed", "<tt>");
        g_hash_table_insert (translations, "/fixed", "</tt>");
        g_hash_table_insert (translations, "smaller", "<font size=-1>");
        g_hash_table_insert (translations, "/smaller", "</font>");
        g_hash_table_insert (translations, "bigger", "<font size=+1>");
        g_hash_table_insert (translations, "/bigger", "</font>");
        g_hash_table_insert (translations, "underline", "<u>");
        g_hash_table_insert (translations, "/underline", "</u>");
        g_hash_table_insert (translations, "center", "<p align=center>");
        g_hash_table_insert (translations, "/center", "</p>");
        g_hash_table_insert (translations, "flushleft", "<p align=left>");
        g_hash_table_insert (translations, "/flushleft", "</p>");
        g_hash_table_insert (translations, "flushright", "<p align=right>");
        g_hash_table_insert (translations, "/flushright", "</p>");
        g_hash_table_insert (translations, "excerpt", "<blockquote>");
        g_hash_table_insert (translations, "/excerpt", "</blockquote>");
        g_hash_table_insert (translations, "paragraph", "<p>");
        g_hash_table_insert (translations, "signature", "<address>");
        g_hash_table_insert (translations, "/signature", "</address>");
        g_hash_table_insert (translations, "comment", "<!-- ");
        g_hash_table_insert (translations, "/comment", " -->");
        g_hash_table_insert (translations, "param", "<!-- ");
        g_hash_table_insert (translations, "/param", " -->");
        g_hash_table_insert (translations, "np", "<hr>");
    }

    text = get_data_wrapper_text (wrapper);
    if (!text)
        return FALSE;

    if (!g_strcasecmp (mime_type, "text/richtext")) {
        enriched = FALSE;
        mail_html_write (md->html, md->stream,
                 "\n<!-- text/richtext -->\n");
    } else {
        enriched = TRUE;
        mail_html_write (md->html, md->stream,
                 "\n<!-- text/enriched -->\n");
    }

    /* This is not great code, but I don't feel like fixing it right
     * now. I mean, it's just text/enriched...
     */
    p = text;
    string = g_string_sized_new (2 * strlen (p));

    while (p) {
        len = strcspn (p, " <>&\n");
        if (len)
            g_string_sprintfa (string, "%.*s", len, p);

        p += len;
        if (!*p)
            break;

        switch (*p++) {
        case ' ':
            while (*p == ' ') {
                g_string_append (string, "&nbsp;");
                p++;
            }
            g_string_append (string, " ");
            break;

        case '\n':
            g_string_append (string, " ");
            if (enriched && nofill <= 0) {
                while (*p == '\n') {
                    g_string_append (string, "<br>");
                    p++;
                }
            }
            break;

        case '>':
            g_string_append (string, "&gt;");
            break;

        case '&':
            g_string_append (string, "&amp;");
            break;

        case '<':
            if (enriched) {
                if (*p == '<') {
                    g_string_append (string, "&lt;");
                    p++;
                    break;
                }
            } else {
                if (strncmp (p, "lt>", 3) == 0) {
                    g_string_append (string, "&lt;");
                    p += 3;
                    break;
                } else if (strncmp (p, "nl>", 3) == 0) {
                    g_string_append (string, "<br>");
                    p += 3;
                    break;
                }
            }

            if (strncmp (p, "nofill>", 7) == 0) {
                nofill++;
                g_string_append (string, "<pre>");
            } else if (strncmp (p, "/nofill>", 8) == 0) {
                nofill--;
                g_string_append (string, "</pre>");
            } else {
                char *copy, *match;

                len = strcspn (p, ">");
                copy = g_strndup (p, len);
                match = g_hash_table_lookup (translations,
                                 copy);
                g_free (copy);
                if (match)
                    g_string_append (string, match);
            }

            p = strchr (p, '>');
            if (p)
                p++;
        }
    }
    g_free (text);

    ba = g_byte_array_new ();
    g_byte_array_append (ba, (const guint8 *)string->str,
                 strlen (string->str));
    g_string_free (string, TRUE);

    xed = g_strdup_printf ("x-evolution-data:%p", part);
    mail_html_write (md->html, md->stream,
             "<iframe src=\"%s\" frameborder=0 scrolling=no>"
             "</iframe>", xed);
    add_url (xed, ba, md);
    camel_object_hook_event (CAMEL_OBJECT (md->current_message),
                 "finalize", free_byte_array, ba);

    return TRUE;
}

static gboolean
handle_text_html (CamelMimePart *part, const char *mime_type,
          MailDisplay *md)
{
    mail_html_write (md->html, md->stream, "\n<!-- text/html -->\n");
    mail_html_write (md->html, md->stream,
             "<iframe src=\"%s\" frameborder=0 scrolling=no>"
             "</iframe>", get_cid (part, md));
    return TRUE;
}

static gboolean
handle_image (CamelMimePart *part, const char *mime_type, MailDisplay *md)
{
    mail_html_write (md->html, md->stream, "<img src=\"%s\">",
             get_cid (part, md));
    return TRUE;
}

static gboolean
handle_multipart_mixed (CamelMimePart *part, const char *mime_type,
            MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    CamelMultipart *mp;
    int i, nparts;
    gboolean output = FALSE;

    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    mp = CAMEL_MULTIPART (wrapper);

    nparts = camel_multipart_get_number (mp);   
    for (i = 0; i < nparts; i++) {
        if (i != 0 && output)
            mail_html_write (md->html, md->stream, "<hr>\n");

        part = camel_multipart_get_part (mp, i);

        output = call_handler_function (part, md);
    }

    return TRUE;
}

static gboolean
handle_multipart_encrypted (CamelMimePart *part, const char *mime_type,
                MailDisplay *md)
{
    CamelDataWrapper *wrapper;
    CamelMimePart *mime_part;
    CamelException ex;
    
    wrapper = camel_medium_get_content_object (CAMEL_MEDIUM (part));
    
    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    
    /* Currently we only handle RFC2015-style PGP encryption. */
    if (!camel_pgp_mime_is_rfc2015_encrypted (part))
        return handle_multipart_mixed (part, mime_type, md);
    
    camel_exception_init (&ex);
    mime_part = mail_crypto_pgp_mime_part_decrypt (part, &ex);
    
    if (camel_exception_is_set (&ex)) {
        /* I guess we just treat this as a multipart/mixed */
        camel_exception_clear (&ex);
        return handle_multipart_mixed (part, mime_type, md);
    } else {
        gboolean retcode;
        
        retcode = call_handler_function (mime_part, md);
        camel_object_unref (CAMEL_OBJECT (mime_part));
        
        return retcode;
    }
}

static gboolean
handle_multipart_signed (CamelMimePart *part, const char *mime_type,
             MailDisplay *md)
{
    CamelDataWrapper *wrapper;
    CamelMultipart *mp;
    CamelException *ex;
    gboolean output = FALSE;
    CamelPgpValidity *valid;
    int nparts, i;
    
    wrapper = camel_medium_get_content_object (CAMEL_MEDIUM (part));
    
    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    
    /* Currently we only handle RFC2015-style PGP signatures. */
    if (!camel_pgp_mime_is_rfc2015_signed (part))
        return handle_multipart_mixed (part, mime_type, md);
    
    ex = camel_exception_new ();
    valid = mail_crypto_pgp_mime_part_verify (part, ex);
    
    /* now display all the subparts *except* the signature */
    mp = CAMEL_MULTIPART (wrapper);
    
    nparts = camel_multipart_get_number (mp);   
    for (i = 0; i < nparts - 1; i++) {
        if (i != 0 && output)
            mail_html_write (md->html, md->stream, "<hr>\n");
        
        part = camel_multipart_get_part (mp, i);
        
        output = call_handler_function (part, md);
    }
    
    /* Now display the "seal-of-authenticity" or something... */
    if (valid && camel_pgp_validity_get_valid (valid)) {
        mail_html_write (md->html, md->stream,
                 "<hr>\n<table><tr valign=top>"
                 "<td><img src=\"%s\"></td>"
                 "<td><font size=-1>%s<br><br>",
                 get_url_for_icon ("wax-seal2.png", md),
                 _("This message is digitally signed and "
                   "has been found to be authentic."));
    } else {
        mail_html_write (md->html, md->stream,
                 "<hr>\n<table><tr valign=top>"
                 "<td><img src=\"%s\"></td>"
                 "<td><font size=-1>%s<br><br>",
                 get_url_for_icon ("wax-seal-broken.png", md),
                 _("This message is digitally signed but can "
                   "not be proven to be authentic."));
    }
    
    if (valid && camel_pgp_validity_get_description (valid)) {
        mail_error_write (md->html, md->stream,
                  camel_pgp_validity_get_description (valid));
        mail_html_write (md->html, md->stream, "<br><br>");
    }
    
    mail_html_write (md->html, md->stream, "</font></td></table>");
    
    camel_exception_free (ex);
    camel_pgp_validity_free (valid);
    
    return TRUE;
}

/* As seen in RFC 2387! */
static gboolean
handle_multipart_related (CamelMimePart *part, const char *mime_type,
              MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    CamelMultipart *mp;
    CamelMimePart *body_part, *display_part = NULL;
    CamelContentType *content_type;
    const char *start;
    int i, nparts;

    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    
    mp = CAMEL_MULTIPART (wrapper);
    nparts = camel_multipart_get_number (mp);   

    content_type = camel_mime_part_get_content_type (part);
    start = header_content_type_param (content_type, "start");
    if (start) {
        int len;

        /* The "start" parameter includes <>s, which Content-Id
         * does not.
         */
        len = strlen (start) - 2;

        for (i = 0; i < nparts; i++) {
            const char *cid;

            body_part = camel_multipart_get_part (mp, i);
            cid = camel_mime_part_get_content_id (body_part);

            if (!strncmp (cid, start + 1, len) &&
                strlen (cid) == len) {
                display_part = body_part;
                break;
            }
        }
    } else {
        /* No start parameter, so it defaults to the first part. */
        display_part = camel_multipart_get_part (mp, 0);
    }

    if (!display_part) {
        /* Oops. Hrmph. */
        return handle_multipart_mixed (part, mime_type, md);
    }

    /* Record the Content-IDs of any non-displayed parts. */
    for (i = 0; i < nparts; i++) {
        body_part = camel_multipart_get_part (mp, i);
        if (body_part == display_part)
            continue;

        get_cid (body_part, md);
    }

    /* Now, display the displayed part. */
    return call_handler_function (display_part, md);
}

/* RFC 2046 says "display the last part that you are able to display". */
static CamelMimePart *
find_preferred_alternative (CamelMultipart *multipart, gboolean want_plain)
{
    int i, nparts;
    CamelMimePart *preferred_part = NULL;
    MailMimeHandler *handler;

    nparts = camel_multipart_get_number (multipart);
    for (i = 0; i < nparts; i++) {
        CamelMimePart *part = camel_multipart_get_part (multipart, i);
        CamelContentType *type = camel_mime_part_get_content_type (part);
        char *mime_type = header_content_type_simple (type);

        g_strdown (mime_type);
        if (want_plain && !strcmp (mime_type, "text/plain"))
            return part;
        handler = mail_lookup_handler (mime_type);
        if (handler && (!preferred_part || !handler->generic))
            preferred_part = part;
        g_free (mime_type);
    }

    return preferred_part;
}

static gboolean
handle_multipart_alternative (CamelMimePart *part, const char *mime_type,
                  MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    CamelMultipart *multipart;
    CamelMimePart *mime_part;
    
    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    
    multipart = CAMEL_MULTIPART (wrapper);
    
    mime_part = find_preferred_alternative (multipart, FALSE);
    if (mime_part)
        return call_handler_function (mime_part, md);
    else
        return handle_multipart_mixed (part, mime_type, md);
}

/* RFC 1740 */
static gboolean
handle_multipart_appledouble (CamelMimePart *part, const char *mime_type,
                  MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    CamelMultipart *multipart;

    g_return_val_if_fail (CAMEL_IS_MULTIPART (wrapper), FALSE);
    
    multipart = CAMEL_MULTIPART (wrapper);

    /* The first part is application/applefile and is not useful
     * to us. The second part _may_ be displayable data. Most
     * likely it's application/octet-stream though.
     */
    part = camel_multipart_get_part (multipart, 1);
    return call_handler_function (part, md);
}

static gboolean
handle_message_rfc822 (CamelMimePart *part, const char *mime_type,
               MailDisplay *md)
{
    CamelDataWrapper *wrapper =
        camel_medium_get_content_object (CAMEL_MEDIUM (part));
    
    g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (wrapper), FALSE);
    
    mail_html_write (md->html, md->stream, "<blockquote>");
    mail_format_mime_message (CAMEL_MIME_MESSAGE (wrapper), md);
    mail_html_write (md->html, md->stream, "</blockquote>");

    return TRUE;
}

static gboolean
handle_message_external_body (CamelMimePart *part, const char *mime_type,
                  MailDisplay *md)
{
    CamelContentType *type;
    const char *access_type;
    char *url = NULL, *desc = NULL;

    type = camel_mime_part_get_content_type (part);
    access_type = header_content_type_param (type, "access-type");
    if (!access_type)
        goto fallback;

    if (!g_strcasecmp (access_type, "ftp") ||
        !g_strcasecmp (access_type, "anon-ftp")) {
        const char *name, *site, *dir, *mode, *ftype;
        char *path;

        name = header_content_type_param (type, "name");
        site = header_content_type_param (type, "site");
        if (name == NULL || site == NULL)
            goto fallback;
        dir = header_content_type_param (type, "directory");
        mode = header_content_type_param (type, "mode");

        /* Generate the path. */
        if (dir) {
            const char *p = dir + strlen (dir);

            path = g_strdup_printf ("%s%s%s%s",
                        *dir == '/' ? "" : "/",
                        dir,
                        *p == '/' ? "" : "/",
                        name);
        } else {
            path = g_strdup_printf ("%s%s",
                        *name == '/' ? "" : "/",
                        name);
        }

        if (mode && *mode == 'A')
            ftype = ";type=A";
        else if (mode && *mode == 'I')
            ftype = ";type=I";
        else
            ftype = "";

        url = g_strdup_printf ("ftp://%s%s%s", site, path, ftype);
        g_free (path);
        desc = g_strdup_printf (_("Pointer to FTP site (%s)"), url);
    } else if (!g_strcasecmp (access_type, "local-file")) {
        const char *name, *site;

        name = header_content_type_param (type, "name");
        if (name == NULL)
            goto fallback;
        site = header_content_type_param (type, "site");

        url = g_strdup_printf ("file://%s%s", *name == '/' ? "" : "/",
                       name);
        if (site) {
            desc = g_strdup_printf (_("Pointer to local file (%s) "
                          "valid at site \"%s\""),
                        name, site);
        } else {
            desc = g_strdup_printf (_("Pointer to local file (%s)"),
                        name);
        }
    } else if (!g_strcasecmp (access_type, "URL")) {
        const char *urlparam;
        char *s, *d;

        /* RFC 2017 */

        urlparam = header_content_type_param (type, "url");
        if (urlparam == NULL)
            goto fallback;

        /* For obscure MIMEy reasons, the URL may be split into
         * multiple words, and needs to be rejoined. (The URL
         * must have any real whitespace %-encoded, so we just
         * get rid of all of it.
         */
        url = g_strdup (urlparam);
        s = d = url;

        while (*s) {
            if (!isspace ((unsigned char)*s))
                *d++ = *s;
            s++;
        }
        *d = *s;

        desc = g_strdup_printf ("Pointer to remote data (%s)", url);
    }

 fallback:
    if (!desc) {
        if (access_type) {
            desc = g_strdup_printf (_("Pointer to unknown "
                          "external data "
                          "(\"%s\" type)"),
                        access_type);
        } else
            desc = g_strdup (_("Malformed external-body part."));
    }

#if 0 /* FIXME */
    handle_mystery (part, md, url, "gnome-globe.png", desc,
            url ? "open it in a browser" : NULL);
#endif

    g_free (desc);
    g_free (url);
    return TRUE;
}

static gboolean
handle_via_bonobo (CamelMimePart *part, const char *mime_type,
           MailDisplay *md)
{
    mail_html_write (md->html, md->stream,
             "<object classid=\"%s\" type=\"%s\"></object>",
             get_cid (part, md), mime_type);
    return TRUE;
}

char *
mail_get_message_body (CamelDataWrapper *data, gboolean want_plain, gboolean *is_html)
{
    CamelMultipart *mp;
    CamelMimePart *subpart;
    int i, nparts;
    char *subtext, *old;
    const char *boundary;
    char *text = NULL;
    CamelContentType *mime_type;
    
    /* We only include text, message, and multipart bodies. */
    mime_type = camel_data_wrapper_get_mime_type_field (data);
    
    /* FIXME: This is wrong. We don't want to include large
     * images. But if we don't do it this way, we don't get
     * the headers...
     */
    if (header_content_type_is (mime_type, "message", "*")) {
        *is_html = FALSE;
        return get_data_wrapper_text (data);
    }
    
    if (header_content_type_is (mime_type, "text", "*")) {
        *is_html = header_content_type_is (mime_type, "text", "html");
        return get_data_wrapper_text (data);
    }
    
    /* If it's not message and it's not text, and it's not
     * multipart, we don't want to deal with it.
     */
    if (!header_content_type_is (mime_type, "multipart", "*"))
        return NULL;
    
    mp = CAMEL_MULTIPART (data);
    
    if (header_content_type_is (mime_type, "multipart", "alternative")) {
        /* Pick our favorite alternative and reply to it. */
        
        subpart = find_preferred_alternative (mp, want_plain);
        if (!subpart)
            return NULL;
        
        data = camel_medium_get_content_object (
            CAMEL_MEDIUM (subpart));
        return mail_get_message_body (data, want_plain, is_html);
    }
    
    nparts = camel_multipart_get_number (mp);
    
    /* Otherwise, concatenate all the parts that we can. If we find
     * an HTML part in there though, return just that: We don't want
     * to deal with merging HTML and non-HTML parts.
     */
    boundary = camel_multipart_get_boundary (mp);
    for (i = 0; i < nparts; i++) {
        subpart = camel_multipart_get_part (mp, i);
        
        if (!mail_part_is_inline (subpart))
            continue;
        
        data = camel_medium_get_content_object (
            CAMEL_MEDIUM (subpart));
        subtext = mail_get_message_body (data, want_plain, is_html);
        if (!subtext)
            continue;
        if (*is_html) {
            g_free (text);
            return subtext;
        }
        
        if (text) {
            old = text;
            text = g_strdup_printf ("%s\n--%s\n%s", old,
                        boundary, subtext);
            g_free (subtext);
            g_free (old);
        } else
            text = subtext;
    }
    
    return text;
}