1 files changed, 130 insertions, 0 deletions
diff --git a/mail/mail-identify.c b/mail/mail-identify.c
new file mode 100644
index 0000000000..2e3f517145
--- /dev/null
+++ b/mail/mail-identify.c
@@ -0,0 +1,130 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ * Author :
+ *  Dan Winship <danw@ximian.com>
+ *
+ *  Copyright 2000, Ximian, Inc. (www.ximian.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * 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 Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <glib.h>
+#include <libgnomevfs/gnome-vfs-utils.h>
+#include <libgnomevfs/gnome-vfs-mime.h>
+#include <libgnomevfs/gnome-vfs-mime-utils.h>
+#include "mail.h"
+
+static const char *identify_by_magic (CamelDataWrapper *data, MailDisplay *md);
+
+/**
+ * mail_identify_mime_part:
+ * @part: a CamelMimePart
+ * @md: the MailDisplay @part is being shown in
+ *
+ * Try to identify the MIME type of the data in @part (which presumably
+ * doesn't have a useful Content-Type).
+ *
+ * Return value: the MIME type, which the caller must free, or %NULL
+ * if it could not be identified.
+ **/
+char *
+mail_identify_mime_part (CamelMimePart *part, MailDisplay *md)
+{
+	const char *filename, *name_type = NULL, *magic_type = NULL;
+	CamelDataWrapper *data;
+	
+	filename = camel_mime_part_get_filename (part);
+	if (filename) {
+		/* GNOME-VFS will misidentify TNEF attachments as MPEG */
+		if (!strcmp (filename, "winmail.dat"))
+			return g_strdup ("application/vnd.ms-tnef");
+		
+		name_type = gnome_vfs_mime_type_from_name (filename);
+	}
+	
+	data = camel_medium_get_content_object (CAMEL_MEDIUM (part));
+	if (!camel_data_wrapper_is_offline (data))
+		magic_type = identify_by_magic (data, md);
+	
+	if (magic_type && name_type) {
+		/* If GNOME-VFS doesn't recognize the data by magic, but it
+		 * contains English words, it will call it text/plain. If the
+		 * filename-based check came up with something different, use
+		 * that instead.
+		 */
+		if (!strcmp (magic_type, "text/plain"))
+			return g_strdup (name_type);
+		
+		/* If if returns "application/octet-stream" try to
+		 * do better with the filename check.
+		 */
+		if (!strcmp (magic_type, "application/octet-stream"))
+			return g_strdup (name_type);
+	}
+	
+	/* If the MIME part data was online, and the magic check
+	 * returned something, use that, since it's more reliable.
+	 */
+	if (magic_type)
+		return g_strdup (magic_type);
+	
+	/* Otherwise try guessing based on the filename */
+	if (name_type)
+		return g_strdup (name_type);
+	
+	/* Another possibility to try is the x-mac-type / x-mac-creator
+	 * parameter to Content-Type used by some Mac email clients. That
+	 * would require a Mac type to mime type conversion table.
+	 */
+	
+#if 0
+	/* If the data part is offline, then we didn't try magic
+	 * before, so force it to be loaded so we can try again later.
+	 * FIXME: In a perfect world, we would not load the content
+	 * just to identify the MIME type.
+	 */
+	/* This is disabled as it just frustrates users more than it helps,
+	   see discussion in bug #11778 */
+	if (camel_data_wrapper_is_offline (data))
+		mail_content_loaded (data, md, TRUE, NULL, NULL, NULL);
+#endif
+	
+	return NULL;
+}
+
+static const char *
+identify_by_magic (CamelDataWrapper *data, MailDisplay *md)
+{
+	CamelStreamMem *memstream;
+	const char *type;
+
+	memstream = (CamelStreamMem *)camel_stream_mem_new();
+	if (camel_data_wrapper_write_to_stream (data, (CamelStream *)memstream) > 0)
+		type = gnome_vfs_get_mime_type_for_data(memstream->buffer->data, memstream->buffer->len);
+	else
+		type = NULL;
+	camel_object_unref(memstream);
+
+	return type;
+}