Attachment-related cleanups.

9 files changed, 220 insertions, 193 deletions

diff --git a/calendar/gui/dialogs/comp-editor.c b/calendar/gui/dialogs/comp-editor.c
index abbf737206..778e69008d 100644
--- a/calendar/gui/dialogs/comp-editor.c
+++ b/calendar/gui/dialogs/comp-editor.c
@@ -3209,7 +3209,7 @@ attachment_loaded_cb (EAttachment *attachment,
 	 */
 
 	file_info = e_attachment_get_file_info (attachment);
-	if (!file_info) {
+	if (file_info == NULL) {
 		/* failed to load an attachment file */
 		e_attachment_load_handle_error (attachment, result, parent);
 		return;
@@ -3697,7 +3697,8 @@ comp_editor_get_mime_attach_list (CompEditor *editor)
 		CamelStream *stream;
 		GByteArray *byte_array;
 		guchar *buffer = NULL;
-		const gchar *desc, *disp;
+		const gchar *description;
+		const gchar *disposition;
 		gint column_id;
 
 		column_id = E_ATTACHMENT_STORE_COLUMN_ATTACHMENT;
@@ -3726,18 +3727,19 @@ comp_editor_get_mime_attach_list (CompEditor *editor)
 		cal_mime_attach->length = byte_array->len;
 		cal_mime_attach->filename =
 			g_strdup (camel_mime_part_get_filename (mime_part));
-		desc = camel_mime_part_get_description (mime_part);
-		if (!desc || *desc == '\0')
-			desc = _("attachment");
-		cal_mime_attach->description = g_strdup (desc);
+		description = camel_mime_part_get_description (mime_part);
+		if (description == NULL || *description == '\0')
+			description = _("attachment");
+		cal_mime_attach->description = g_strdup (description);
 		cal_mime_attach->content_type = g_strdup (
 			camel_data_wrapper_get_mime_type (wrapper));
 		cal_mime_attach->content_id = g_strdup (
 			camel_mime_part_get_content_id (mime_part));
 
-		disp = camel_mime_part_get_disposition (mime_part);
-		if (disp && !g_ascii_strcasecmp (disp, "inline"))
-			cal_mime_attach->disposition = TRUE;
+		disposition = camel_mime_part_get_disposition (mime_part);
+		cal_mime_attach->disposition =
+			(disposition != NULL) &&
+			(g_ascii_strcasecmp (disposition, "inline") == 0);
 
 		attach_list = g_slist_append (attach_list, cal_mime_attach);
 
diff --git a/e-util/e-attachment-button.c b/e-util/e-attachment-button.c
index a2057e3354..7778bb106f 100644
--- a/e-util/e-attachment-button.c
+++ b/e-util/e-attachment-button.c
@@ -271,58 +271,57 @@ attachment_button_expand_drag_data_get_cb (EAttachmentButton *button,
                                            guint time)
 {
 	EAttachmentView *view;
+	EAttachment *attachment;
+	gchar *mime_type = NULL;
 
-	if (button->priv->attachment) {
-		gchar *mime_type;
-
-		mime_type = e_attachment_get_mime_type (
-			button->priv->attachment);
-
-		if (mime_type) {
-			gboolean processed = FALSE;
-			GdkAtom atom;
-			gchar *atom_name;
-
-			atom = gtk_selection_data_get_target (selection);
-			atom_name = gdk_atom_name (atom);
-
-			if (g_strcmp0 (atom_name, mime_type) == 0) {
-				CamelMimePart *mime_part;
-
-				mime_part = e_attachment_get_mime_part (
-					button->priv->attachment);
-
-				if (CAMEL_IS_MIME_PART (mime_part)) {
-					CamelDataWrapper *wrapper;
-					CamelStream *stream;
-					GByteArray *buffer;
-
-					buffer = g_byte_array_new ();
-					stream = camel_stream_mem_new ();
-					camel_stream_mem_set_byte_array (
-						CAMEL_STREAM_MEM (stream),
-						buffer);
-					wrapper = camel_medium_get_content (
-						CAMEL_MEDIUM (mime_part));
-					camel_data_wrapper_decode_to_stream_sync (
-						wrapper, stream, NULL, NULL);
-					g_object_unref (stream);
-
-					gtk_selection_data_set (
-						selection, atom, 8,
-						buffer->data, buffer->len);
-					processed = TRUE;
-
-					g_byte_array_free (buffer, TRUE);
-				}
-			}
+	attachment = e_attachment_button_get_attachment (button);
+
+	if (attachment != NULL)
+		mime_type = e_attachment_get_mime_type (attachment);
+
+	if (mime_type != NULL) {
+		gboolean processed = FALSE;
+		GdkAtom atom;
+		gchar *atom_name;
+
+		atom = gtk_selection_data_get_target (selection);
+		atom_name = gdk_atom_name (atom);
+
+		if (g_strcmp0 (atom_name, mime_type) == 0) {
+			CamelMimePart *mime_part;
+
+			mime_part = e_attachment_get_mime_part (attachment);
 
-			g_free (atom_name);
-			g_free (mime_type);
+			if (mime_part != NULL) {
+				CamelDataWrapper *wrapper;
+				CamelStream *stream;
+				GByteArray *buffer;
 
-			if (processed)
-				return;
+				buffer = g_byte_array_new ();
+				stream = camel_stream_mem_new ();
+				camel_stream_mem_set_byte_array (
+					CAMEL_STREAM_MEM (stream),
+					buffer);
+				wrapper = camel_medium_get_content (
+					CAMEL_MEDIUM (mime_part));
+				camel_data_wrapper_decode_to_stream_sync (
+					wrapper, stream, NULL, NULL);
+				g_object_unref (stream);
+
+				gtk_selection_data_set (
+					selection, atom, 8,
+					buffer->data, buffer->len);
+				processed = TRUE;
+
+				g_byte_array_free (buffer, TRUE);
+			}
 		}
+
+		g_free (atom_name);
+		g_free (mime_type);
+
+		if (processed)
+			return;
 	}
 
 	view = e_attachment_button_get_view (button);
@@ -787,11 +786,11 @@ e_attachment_button_set_attachment (EAttachmentButton *button,
 	list = gtk_target_list_new (NULL, 0);
 	gtk_target_list_add_uri_targets (list, 0);
 
-	if (attachment) {
+	if (attachment != NULL) {
 		gchar *simple_type;
 
 		simple_type = e_attachment_get_mime_type (attachment);
-		if (simple_type) {
+		if (simple_type != NULL) {
 			GtkTargetEntry attach_entry[] = { { NULL, 0, 2 } };
 
 			attach_entry[0].target = simple_type;
diff --git a/e-util/e-attachment-handler-image.c b/e-util/e-attachment-handler-image.c
index 36c3a83614..602f001ba6 100644
--- a/e-util/e-attachment-handler-image.c
+++ b/e-util/e-attachment-handler-image.c
@@ -155,9 +155,7 @@ attachment_handler_image_update_actions_cb (EAttachmentView *view,
                                             EAttachmentHandler *handler)
 {
 	EAttachment *attachment;
-	GFileInfo *file_info;
 	GtkActionGroup *action_group;
-	const gchar *content_type;
 	gchar *mime_type;
 	GList *selected;
 	gboolean visible = FALSE;
@@ -168,10 +166,6 @@ attachment_handler_image_update_actions_cb (EAttachmentView *view,
 		goto exit;
 
 	attachment = E_ATTACHMENT (selected->data);
-	file_info = e_attachment_get_file_info (attachment);
-
-	if (file_info == NULL)
-		goto exit;
 
 	if (e_attachment_get_loading (attachment))
 		goto exit;
@@ -179,10 +173,10 @@ attachment_handler_image_update_actions_cb (EAttachmentView *view,
 	if (e_attachment_get_saving (attachment))
 		goto exit;
 
-	content_type = g_file_info_get_content_type (file_info);
-
-	mime_type = g_content_type_get_mime_type (content_type);
-	visible = (g_ascii_strncasecmp (mime_type, "image/", 6) == 0);
+	mime_type = e_attachment_get_mime_type (attachment);
+	visible =
+		(mime_type != NULL) &&
+		(g_ascii_strncasecmp (mime_type, "image/", 6) == 0);
 	g_free (mime_type);
 
 exit:
diff --git a/e-util/e-attachment-store.c b/e-util/e-attachment-store.c
index 55bc795095..8ea2f8965b 100644
--- a/e-util/e-attachment-store.c
+++ b/e-util/e-attachment-store.c
@@ -727,18 +727,18 @@ e_attachment_store_get_uris_async (EAttachmentStore *store,
 	for (iter = attachment_list; iter != NULL; iter = iter->next) {
 		EAttachment *attachment = iter->data;
 		GFile *file;
-		gchar *uri;
 
 		file = e_attachment_get_file (attachment);
-		if (file == NULL)
-			continue;
+		if (file != NULL) {
+			gchar *uri;
 
-		uri = g_file_get_uri (file);
-		uri_context->uris[uri_context->index++] = uri;
+			uri = g_file_get_uri (file);
+			uri_context->uris[uri_context->index++] = uri;
 
-		/* Mark the list node for deletion. */
-		trash = g_list_prepend (trash, iter);
-		g_object_unref (attachment);
+			/* Mark the list node for deletion. */
+			trash = g_list_prepend (trash, iter);
+			g_object_unref (attachment);
+		}
 	}
 
 	/* Expunge the list. */
diff --git a/e-util/e-attachment.c b/e-util/e-attachment.c
index 495c805f16..9f758c510c 100644
--- a/e-util/e-attachment.c
+++ b/e-util/e-attachment.c
@@ -110,34 +110,35 @@ create_system_thumbnail (EAttachment *attachment,
 {
 	GFile *file;
 	GFile *icon_file;
+	gchar *file_path = NULL;
 	gchar *thumbnail = NULL;
+	gboolean success = FALSE;
 
-	g_return_val_if_fail (attachment != NULL, FALSE);
+	g_return_val_if_fail (E_IS_ATTACHMENT (attachment), FALSE);
 	g_return_val_if_fail (icon != NULL, FALSE);
 
 	file = e_attachment_get_file (attachment);
+	if (file != NULL)
+		file_path = g_file_get_path (file);
 
-	if (file && g_file_has_uri_scheme (file, "file")) {
-		gchar *path = g_file_get_path (file);
-		if (path) {
-			thumbnail = e_icon_factory_create_thumbnail (path);
-			g_free (path);
-		}
+	if (file_path != NULL) {
+		thumbnail = e_icon_factory_create_thumbnail (file_path);
+		g_free (file_path);
 	}
 
 	if (thumbnail == NULL)
-		return FALSE;
+		goto exit;
 
 	icon_file = g_file_new_for_path (thumbnail);
 
-	if (*icon)
+	if (*icon != NULL)
 		g_object_unref (*icon);
 
 	*icon = g_file_icon_new (icon_file);
 
 	g_object_unref (icon_file);
 
-	if (file) {
+	if (file != NULL) {
 		GFileInfo *file_info;
 		const gchar *attribute;
 
@@ -151,7 +152,10 @@ create_system_thumbnail (EAttachment *attachment,
 
 	g_free (thumbnail);
 
-	return TRUE;
+	success = TRUE;
+
+exit:
+	return success;
 }
 
 static gchar *
@@ -535,7 +539,7 @@ attachment_set_property (GObject *object,
 		case PROP_MIME_PART:
 			e_attachment_set_mime_part (
 				E_ATTACHMENT (object),
-				g_value_get_boxed (value));
+				g_value_get_object (value));
 			return;
 
 		case PROP_REFERENCE:
@@ -563,79 +567,92 @@ attachment_get_property (GObject *object,
 	switch (property_id) {
 		case PROP_CAN_SHOW:
 			g_value_set_boolean (
-				value, e_attachment_get_can_show (
+				value,
+				e_attachment_get_can_show (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_DISPOSITION:
 			g_value_set_string (
-				value, e_attachment_get_disposition (
+				value,
+				e_attachment_get_disposition (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_ENCRYPTED:
 			g_value_set_int (
-				value, e_attachment_get_encrypted (
+				value,
+				e_attachment_get_encrypted (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_FILE:
 			g_value_set_object (
-				value, e_attachment_get_file (
+				value,
+				e_attachment_get_file (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_FILE_INFO:
 			g_value_set_object (
-				value, e_attachment_get_file_info (
+				value,
+				e_attachment_get_file_info (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_ICON:
 			g_value_set_object (
-				value, e_attachment_get_icon (
+				value,
+				e_attachment_get_icon (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_SHOWN:
 			g_value_set_boolean (
-				value, e_attachment_get_shown (
+				value,
+				e_attachment_get_shown (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_LOADING:
 			g_value_set_boolean (
-				value, e_attachment_get_loading (
+				value,
+				e_attachment_get_loading (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_MIME_PART:
-			g_value_set_boxed (
-				value, e_attachment_get_mime_part (
+			g_value_set_object (
+				value,
+				e_attachment_get_mime_part (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_PERCENT:
 			g_value_set_int (
-				value, e_attachment_get_percent (
+				value,
+				e_attachment_get_percent (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_REFERENCE:
 			g_value_set_boxed (
-				value, e_attachment_get_reference (
+				value,
+				e_attachment_get_reference (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_SAVING:
 			g_value_set_boolean (
-				value, e_attachment_get_saving (
+				value,
+				e_attachment_get_saving (
 				E_ATTACHMENT (object)));
 			return;
 
 		case PROP_SIGNED:
 			g_value_set_int (
-				value, e_attachment_get_signed (
+				value,
+				e_attachment_get_signed (
 				E_ATTACHMENT (object)));
 			return;
 	}
@@ -650,30 +667,11 @@ attachment_dispose (GObject *object)
 
 	priv = E_ATTACHMENT_GET_PRIVATE (object);
 
-	if (priv->file != NULL) {
-		g_object_unref (priv->file);
-		priv->file = NULL;
-	}
-
-	if (priv->icon != NULL) {
-		g_object_unref (priv->icon);
-		priv->icon = NULL;
-	}
-
-	if (priv->file_info != NULL) {
-		g_object_unref (priv->file_info);
-		priv->file_info = NULL;
-	}
-
-	if (priv->cancellable != NULL) {
-		g_object_unref (priv->cancellable);
-		priv->cancellable = NULL;
-	}
-
-	if (priv->mime_part != NULL) {
-		g_object_unref (priv->mime_part);
-		priv->mime_part = NULL;
-	}
+	g_clear_object (&priv->file);
+	g_clear_object (&priv->icon);
+	g_clear_object (&priv->file_info);
+	g_clear_object (&priv->cancellable);
+	g_clear_object (&priv->mime_part);
 
 	if (priv->emblem_timeout_id > 0) {
 		g_source_remove (priv->emblem_timeout_id);
@@ -1198,10 +1196,13 @@ e_attachment_set_file_info (EAttachment *attachment,
 
 /**
  * e_attachment_get_mime_type:
+ * @attachment: an #EAttachment
+ *
+ * Returns the MIME type of @attachment according to its #GFileInfo.
+ * If the @attachment has no #GFileInfo then the function returns %NULL.
+ * Free the returned MIME type string with g_free().
  *
- * Returns mime_type part of the file_info as a newly allocated string,
- * which should be freed with g_free().
- * Returns NULL, if mime_type not found or set on the attachment.
+ * Returns: a newly-allocated MIME type string, or %NULL
  **/
 gchar *
 e_attachment_get_mime_type (EAttachment *attachment)
@@ -1415,7 +1416,9 @@ e_attachment_is_rfc822 (EAttachment *attachment)
 	g_return_val_if_fail (E_IS_ATTACHMENT (attachment), FALSE);
 
 	mime_type = e_attachment_get_mime_type (attachment);
-	is_rfc822 = mime_type && g_ascii_strcasecmp (mime_type, "message/rfc822") == 0;
+	is_rfc822 =
+		(mime_type != NULL) &&
+		(g_ascii_strcasecmp (mime_type, "message/rfc822") == 0);
 	g_free (mime_type);
 
 	return is_rfc822;
@@ -1789,7 +1792,8 @@ attachment_load_from_mime_part_thread (GSimpleAsyncResult *simple,
 	CamelStream *null;
 	CamelDataWrapper *dw;
 
-	load_context = g_object_get_data (G_OBJECT (simple), ATTACHMENT_LOAD_CONTEXT);
+	load_context = g_object_get_data (
+		G_OBJECT (simple), ATTACHMENT_LOAD_CONTEXT);
 	g_return_if_fail (load_context != NULL);
 	g_object_set_data (G_OBJECT (simple), ATTACHMENT_LOAD_CONTEXT, NULL);
 
@@ -1849,15 +1853,16 @@ attachment_load_from_mime_part_thread (GSimpleAsyncResult *simple,
 			} else {
 				CamelDataWrapper *content;
 
-				content = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
+				content = camel_medium_get_content (
+					CAMEL_MEDIUM (mime_part));
 				if (CAMEL_IS_MIME_MESSAGE (content))
 					msg = CAMEL_MIME_MESSAGE (content);
 			}
 
-			if (msg)
+			if (msg != NULL)
 				subject = camel_mime_message_get_subject (msg);
 
-			if (subject && *subject)
+			if (subject != NULL && *subject != '\0')
 				string = subject;
 		}
 	} else {
@@ -1883,7 +1888,8 @@ attachment_load_from_mime_part_thread (GSimpleAsyncResult *simple,
 	dw = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
 	null = camel_stream_null_new ();
 	/* this actually downloads the part and makes it available later */
-	camel_data_wrapper_decode_to_stream_sync (dw, null, attachment->priv->cancellable, NULL);
+	camel_data_wrapper_decode_to_stream_sync (
+		dw, null, attachment->priv->cancellable, NULL);
 	g_file_info_set_size (file_info, CAMEL_STREAM_NULL (null)->written);
 	g_object_unref (null);
 
@@ -1944,7 +1950,9 @@ e_attachment_load_async (EAttachment *attachment,
 			attachment_load_query_info_cb, load_context);
 
 	} else if (mime_part != NULL) {
-		g_object_set_data (G_OBJECT (load_context->simple), ATTACHMENT_LOAD_CONTEXT, load_context);
+		g_object_set_data (
+			G_OBJECT (load_context->simple),
+			ATTACHMENT_LOAD_CONTEXT, load_context);
 
 		g_simple_async_result_run_in_thread (
 			load_context->simple,
@@ -1967,14 +1975,18 @@ e_attachment_load_finish (EAttachment *attachment,
 
 	simple = G_SIMPLE_ASYNC_RESULT (result);
 	load_context = g_simple_async_result_get_op_res_gpointer (simple);
-	if (load_context && load_context->mime_part) {
+
+	if (load_context != NULL && load_context->mime_part != NULL) {
 		const gchar *string;
 
-		string = camel_mime_part_get_disposition (load_context->mime_part);
+		string = camel_mime_part_get_disposition (
+			load_context->mime_part);
 		e_attachment_set_disposition (attachment, string);
 
-		e_attachment_set_file_info (attachment, load_context->file_info);
-		e_attachment_set_mime_part (attachment, load_context->mime_part);
+		e_attachment_set_file_info (
+			attachment, load_context->file_info);
+		e_attachment_set_mime_part (
+			attachment, load_context->mime_part);
 	}
 
 	g_simple_async_result_propagate_error (simple, error);
diff --git a/em-format/e-mail-formatter-attachment.c b/em-format/e-mail-formatter-attachment.c
index 0a100e0987..1003b55eef 100644
--- a/em-format/e-mail-formatter-attachment.c
+++ b/em-format/e-mail-formatter-attachment.c
@@ -209,7 +209,7 @@ emfe_attachment_format (EMailFormatterExtension *extension,
 			display_name = g_file_info_get_display_name (fi);
 
 			description = e_attachment_get_description (attachment);
-			if (description && *description) {
+			if (description != NULL && *description != '\0') {
 				name = g_strdup_printf (
 					"<h2>Attachment: %s (%s)</h2>\n",
 					description, display_name);
@@ -219,7 +219,9 @@ emfe_attachment_format (EMailFormatterExtension *extension,
 					display_name);
 			}
 
-			camel_stream_write_string (stream, name, cancellable, NULL);
+			camel_stream_write_string (
+				stream, name, cancellable, NULL);
+
 			g_free (name);
 
 			g_object_unref (attachment);
diff --git a/em-format/e-mail-parser.c b/em-format/e-mail-parser.c
index 929662f943..f31e0ca199 100644
--- a/em-format/e-mail-parser.c
+++ b/em-format/e-mail-parser.c
@@ -732,22 +732,22 @@ e_mail_parser_wrap_as_attachment (EMailParser *parser,
 		NULL);
 
 	if (size != 0) {
-		GFileInfo *fileinfo;
+		GFileInfo *file_info;
 
-		fileinfo = e_attachment_get_file_info (attachment);
+		file_info = e_attachment_get_file_info (attachment);
 
-		if (!fileinfo) {
-			fileinfo = g_file_info_new ();
+		if (file_info == NULL) {
+			file_info = g_file_info_new ();
 			g_file_info_set_content_type (
-				fileinfo, empa->snoop_mime_type);
+				file_info, empa->snoop_mime_type);
 		} else {
-			g_object_ref (fileinfo);
+			g_object_ref (file_info);
 		}
 
-		g_file_info_set_size (fileinfo, size);
-		e_attachment_set_file_info (attachment, fileinfo);
+		g_file_info_set_size (file_info, size);
+		e_attachment_set_file_info (attachment, file_info);
 
-		g_object_unref (fileinfo);
+		g_object_unref (file_info);
 	}
 
 	g_object_unref (attachment);
diff --git a/modules/calendar/e-cal-attachment-handler.c b/modules/calendar/e-cal-attachment-handler.c
index 539a5ba3a4..343d4bad14 100644
--- a/modules/calendar/e-cal-attachment-handler.c
+++ b/modules/calendar/e-cal-attachment-handler.c
@@ -80,7 +80,7 @@ attachment_handler_get_component (EAttachment *attachment)
 		return NULL;
 
 	mime_part = e_attachment_get_mime_part (attachment);
-	if (!CAMEL_IS_MIME_PART (mime_part))
+	if (mime_part == NULL)
 		return NULL;
 
 	buffer = g_byte_array_new ();
diff --git a/modules/mail/e-mail-attachment-handler.c b/modules/mail/e-mail-attachment-handler.c
index d6caecf556..d041bc9ad1 100644
--- a/modules/mail/e-mail-attachment-handler.c
+++ b/modules/mail/e-mail-attachment-handler.c
@@ -65,10 +65,13 @@ mail_attachment_handler_get_selected_message (EAttachmentHandler *handler)
 	EAttachment *attachment;
 	EAttachmentView *view;
 	CamelMimePart *mime_part;
-	CamelDataWrapper *wrapper;
 	CamelMimeMessage *message = NULL;
-	CamelContentType *content_type;
+	CamelDataWrapper *outer_wrapper;
+	CamelContentType *outer_content_type;
+	CamelDataWrapper *inner_wrapper;
+	CamelContentType *inner_content_type;
 	GList *selected;
+	gboolean inner_and_outer_content_types_match;
 
 	view = e_attachment_handler_get_view (handler);
 
@@ -77,41 +80,55 @@ mail_attachment_handler_get_selected_message (EAttachmentHandler *handler)
 
 	attachment = E_ATTACHMENT (selected->data);
 	mime_part = e_attachment_get_mime_part (attachment);
-	wrapper = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
-
-	content_type = camel_data_wrapper_get_mime_type_field (wrapper);
-	if (content_type && camel_content_type_is (content_type, "message", "rfc822")) {
-		CamelDataWrapper *inner;
-		CamelContentType *inner_content_type;
-
-		inner = camel_medium_get_content (CAMEL_MEDIUM (wrapper));
-		inner_content_type = camel_data_wrapper_get_mime_type_field (inner);
-		if (!camel_content_type_is (inner_content_type, content_type->type, content_type->subtype)) {
-			CamelStream *mem;
-
-			/* Create a message copy in case the inner content-type doesn't match
-			 * the mime_part's content type, which can happen for multipart/digest,
-			 * where it confuses the formatter on reply, which skips all rfc822 subparts.
-			*/
-			mem = camel_stream_mem_new ();
-			camel_data_wrapper_write_to_stream_sync (CAMEL_DATA_WRAPPER (wrapper), mem, NULL, NULL);
-
-			g_seekable_seek (G_SEEKABLE (mem), 0, G_SEEK_SET, NULL, NULL);
-			message = camel_mime_message_new ();
-			if (!camel_data_wrapper_construct_from_stream_sync (CAMEL_DATA_WRAPPER (message), mem, NULL, NULL)) {
-				g_object_unref (message);
-				message = NULL;
-			}
-
-			g_object_unref (mem);
-		}
+
+	outer_wrapper =
+		camel_medium_get_content (CAMEL_MEDIUM (mime_part));
+	outer_content_type =
+		camel_data_wrapper_get_mime_type_field (outer_wrapper);
+
+	if (!camel_content_type_is (outer_content_type, "message", "rfc822"))
+		goto exit;
+
+	inner_wrapper =
+		camel_medium_get_content (CAMEL_MEDIUM (outer_wrapper));
+	inner_content_type =
+		camel_data_wrapper_get_mime_type_field (inner_wrapper);
+
+	inner_and_outer_content_types_match =
+		camel_content_type_is (
+			inner_content_type,
+			outer_content_type->type,
+			outer_content_type->subtype);
+
+	if (!inner_and_outer_content_types_match) {
+		CamelStream *mem;
+		gboolean success;
+
+		/* Create a message copy in case the inner content
+		 * type doesn't match the mime_part's content type,
+		 * which can happen for multipart/digest, where it
+		 * confuses the formatter on reply, which skips all
+		 * rfc822 subparts. */
+		mem = camel_stream_mem_new ();
+		camel_data_wrapper_write_to_stream_sync (
+			CAMEL_DATA_WRAPPER (outer_wrapper), mem, NULL, NULL);
+
+		g_seekable_seek (
+			G_SEEKABLE (mem), 0, G_SEEK_SET, NULL, NULL);
+		message = camel_mime_message_new ();
+		success = camel_data_wrapper_construct_from_stream_sync (
+			CAMEL_DATA_WRAPPER (message), mem, NULL, NULL);
+		if (!success)
+			g_clear_object (&message);
+
+		g_object_unref (mem);
 	}
 
-	if (!message)
-		message = g_object_ref (wrapper);
+exit:
+	if (message == NULL)
+		message = g_object_ref (outer_wrapper);
 
-	g_list_foreach (selected, (GFunc) g_object_unref, NULL);
-	g_list_free (selected);
+	g_list_free_full (selected, (GDestroyNotify) g_object_unref);
 
 	return message;
 }
@@ -445,7 +462,6 @@ mail_attachment_handler_update_actions (EAttachmentView *view,
 {
 	EAttachment *attachment;
 	CamelMimePart *mime_part;
-	CamelDataWrapper *wrapper;
 	GtkActionGroup *action_group;
 	GList *selected;
 	gboolean visible = FALSE;
@@ -463,12 +479,14 @@ mail_attachment_handler_update_actions (EAttachmentView *view,
 
 	mime_part = e_attachment_get_mime_part (attachment);
 
-	if (!CAMEL_IS_MIME_PART (mime_part))
-		goto exit;
-
-	wrapper = camel_medium_get_content (CAMEL_MEDIUM (mime_part));
+	if (mime_part != NULL) {
+		CamelMedium *medium;
+		CamelDataWrapper *content;
 
-	visible = CAMEL_IS_MIME_MESSAGE (wrapper);
+		medium = CAMEL_MEDIUM (mime_part);
+		content = camel_medium_get_content (medium);
+		visible = CAMEL_IS_MIME_MESSAGE (content);
+	}
 
 exit:
 	action_group = e_attachment_view_get_action_group (view, "mail");