From 10ceb309102698f8925cd56d283b8337c0cae610 Mon Sep 17 00:00:00 2001
From: Milan Crha <mcrha@redhat.com>
Date: Thu, 4 Jan 2018 19:04:46 +0100
Subject: [PATCH] Drag&drop of attachment button from mail preview does nothing

It's using the same mime type, but the code to make it a real file
or anything like that fails. With this change the button (or the image
of it on the right side of the button) can be dragged into the folder
tree or message list, importing it into the mail folder.
---
 src/mail/e-mail-display.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)

diff --git a/src/mail/e-mail-display.c b/src/mail/e-mail-display.c
index 0e68e8df50..126f8f931e 100644
--- a/src/mail/e-mail-display.c
+++ b/src/mail/e-mail-display.c
@@ -1777,6 +1777,71 @@ mail_display_suggest_filename (EWebView *web_view,
 }
 
 static void
+mail_display_save_part_for_drop (CamelMimePart *mime_part,
+				 GtkSelectionData *data)
+{
+	gchar *tmp, *path, *filename;
+	const gchar *part_filename;
+	CamelDataWrapper *dw;
+
+	g_return_if_fail (CAMEL_IS_MIME_PART (mime_part));
+	g_return_if_fail (data != NULL);
+
+	tmp = g_strdup_printf (PACKAGE "-%s-XXXXXX", g_get_user_name ());
+	path = e_mkdtemp (tmp);
+	g_free (tmp);
+
+	g_return_if_fail (path != NULL);
+
+	part_filename = camel_mime_part_get_filename (mime_part);
+	if (!part_filename || !*part_filename) {
+		CamelDataWrapper *content;
+
+		content = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
+
+		if (CAMEL_IS_MIME_MESSAGE (content))
+			part_filename = camel_mime_message_get_subject (CAMEL_MIME_MESSAGE (content));
+	}
+
+	if (!part_filename || !*part_filename)
+		part_filename = "mail-part";
+
+	tmp = g_strdup (part_filename);
+	e_filename_make_safe (tmp);
+
+	filename = g_build_filename (path, tmp, NULL);
+	g_free (tmp);
+
+	dw = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
+	g_warn_if_fail (dw);
+
+	if (dw) {
+		CamelStream *stream;
+
+		stream = camel_stream_fs_new_with_name (filename, O_CREAT | O_TRUNC | O_WRONLY, 0666, NULL);
+		if (stream) {
+			if (camel_data_wrapper_decode_to_stream_sync (dw, stream, NULL, NULL)) {
+				tmp = g_filename_to_uri (filename, NULL, NULL);
+				if (tmp) {
+					gtk_selection_data_set (
+						data,
+						gtk_selection_data_get_data_type (data),
+						gtk_selection_data_get_format (data),
+						(const guchar *) tmp, strlen (tmp));
+					g_free (tmp);
+				}
+			}
+
+			camel_stream_close (stream, NULL, NULL);
+			g_object_unref (stream);
+		}
+	}
+
+	g_free (filename);
+	g_free (path);
+}
+
+static void
 mail_display_drag_data_get (GtkWidget *widget,
                             GdkDragContext *context,
                             GtkSelectionData *data,
@@ -1800,6 +1865,52 @@ mail_display_drag_data_get (GtkWidget *widget,
 
 	mime_part = camel_mime_part_from_cid (display, uri);
 
+	if (!mime_part && g_str_has_prefix (uri, "mail:")) {
+		SoupURI *soup_uri;
+		const gchar *soup_query;
+
+		soup_uri = soup_uri_new (uri);
+		if (soup_uri) {
+			soup_query = soup_uri_get_query (soup_uri);
+			if (soup_query) {
+				GHashTable *query;
+				const gchar *part_id_raw;
+
+				query = soup_form_decode (soup_query);
+				part_id_raw = query ? g_hash_table_lookup (query, "part_id") : NULL;
+				if (part_id_raw && *part_id_raw) {
+					EMailPartList *part_list;
+					EMailPart *mail_part;
+
+					part_list = e_mail_display_get_part_list (display);
+					if (part_list) {
+						gchar *part_id = soup_uri_decode (part_id_raw);
+
+						mail_part = e_mail_part_list_ref_part (part_list, part_id);
+						g_free (part_id);
+
+						if (mail_part) {
+							CamelMimePart *part;
+
+							part = e_mail_part_ref_mime_part (mail_part);
+							if (part) {
+								mail_display_save_part_for_drop (part, data);
+							}
+
+							g_clear_object (&part);
+							g_object_unref (mail_part);
+						}
+					}
+				}
+
+				if (query)
+					g_hash_table_unref (query);
+			}
+
+			soup_uri_free (soup_uri);
+		}
+	}
+
 	if (!mime_part)
 		goto out;
 
-- 
2.11.4.GIT