EMailParserExtension: Collect EMailParts in a GQueue.

Collect EMailParts in a GQueue provided to the EMailParserExtension,
and change the return type of parse() to gboolean to indicate whether
the given CamelMimePart was handled (even if no parts were added to
the output GQueue).

This avoids the awkward corner case of a parser extension returning a
linked list node with a NULL data member to indicate the CamelMimePart
was handled but no EMailParts produced, and then having to watch out
for that NULL data member corner case throughout the application.

Also, remove the GCancellable parameter from e_mail_parser_error() and
e_mail_parser_wrap_as_attachment() since neither function blocks.

1 files changed, 53 insertions, 52 deletions

diff --git a/em-format/e-mail-parser.c b/em-format/e-mail-parser.c
index 8e5ccd4ef8..55e6eef47f 100644
--- a/em-format/e-mail-parser.c
+++ b/em-format/e-mail-parser.c
@@ -62,11 +62,11 @@ mail_parser_run (EMailParser *parser,
 {
 	EMailExtensionRegistry *reg;
 	CamelMimeMessage *message;
-	EMailPart *part;
+	EMailPart *mail_part;
 	GQueue *parsers;
+	GQueue mail_part_queue = G_QUEUE_INIT;
 	GList *iter;
 	GString *part_id;
-	GSList *list_of_parts;
 
 	message = e_mail_part_list_get_message (part_list);
 
@@ -79,18 +79,19 @@ mail_parser_run (EMailParser *parser,
 		parsers = e_mail_extension_registry_get_for_mime_type (
 			reg, "message/*");
 
-	/* parsers == NULL means, that the internal Evolution parser
-	 * extensions were not loaded. Something is terribly wrong. */
+	/* No parsers means the internal Evolution parser
+	 * extensions were not loaded. Something is terribly wrong! */
 	g_return_if_fail (parsers != NULL);
 
 	part_id = g_string_new (".message");
 
-	part = e_mail_part_new (CAMEL_MIME_PART (message), ".message");
-	e_mail_part_list_add_part (part_list, part);
-	e_mail_part_unref (part);
+	mail_part = e_mail_part_new (CAMEL_MIME_PART (message), ".message");
+	e_mail_part_list_add_part (part_list, mail_part);
+	e_mail_part_unref (mail_part);
 
 	for (iter = parsers->head; iter; iter = iter->next) {
 		EMailParserExtension *extension;
+		gboolean message_handled;
 
 		if (g_cancellable_is_cancelled (cancellable))
 			break;
@@ -99,24 +100,19 @@ mail_parser_run (EMailParser *parser,
 		if (!extension)
 			continue;
 
-		list_of_parts = e_mail_parser_extension_parse (
+		message_handled = e_mail_parser_extension_parse (
 			extension, parser,
 			CAMEL_MIME_PART (message),
-			part_id, cancellable);
+			part_id, cancellable, &mail_part_queue);
 
-		if (list_of_parts != NULL)
+		if (message_handled)
 			break;
 	}
 
-	while (list_of_parts != NULL) {
-		part = list_of_parts->data;
-		if (part != NULL) {
-			e_mail_part_list_add_part (part_list, part);
-			e_mail_part_unref (part);
-		}
-
-		list_of_parts = g_slist_delete_link (
-			list_of_parts, list_of_parts);
+	while (!g_queue_is_empty (&mail_part_queue)) {
+		mail_part = g_queue_pop_head (&mail_part_queue);
+		e_mail_part_list_add_part (part_list, mail_part);
+		e_mail_part_unref (mail_part);
 	}
 
 	g_string_free (part_id, TRUE);
@@ -428,15 +424,16 @@ e_mail_parser_parse_finish (EMailParser *parser,
 	return g_object_ref (part_list);
 }
 
-GSList *
+gboolean
 e_mail_parser_parse_part (EMailParser *parser,
                           CamelMimePart *part,
                           GString *part_id,
-                          GCancellable *cancellable)
+                          GCancellable *cancellable,
+                          GQueue *out_mail_parts)
 {
 	CamelContentType *ct;
 	gchar *mime_type;
-	GSList *list;
+	gint n_parts_queued = 0;
 
 	ct = camel_mime_part_get_content_type (part);
 	if (!ct) {
@@ -448,32 +445,31 @@ e_mail_parser_parse_part (EMailParser *parser,
 		g_free (tmp);
 	}
 
-	list = e_mail_parser_parse_part_as (
-		parser, part, part_id, mime_type, cancellable);
+	n_parts_queued = e_mail_parser_parse_part_as (
+		parser, part, part_id, mime_type,
+		cancellable, out_mail_parts);
 
 	if (ct) {
 		g_free (mime_type);
 	}
 
-	return list;
+	return n_parts_queued;
 }
 
-GSList *
+gboolean
 e_mail_parser_parse_part_as (EMailParser *parser,
                              CamelMimePart *part,
                              GString *part_id,
                              const gchar *mime_type,
-                             GCancellable *cancellable)
+                             GCancellable *cancellable,
+                             GQueue *out_mail_parts)
 {
 	GQueue *parsers;
 	GList *iter;
 	EMailExtensionRegistry *reg;
 	EMailParserClass *parser_class;
-	GSList *part_list = NULL;
 	gchar *as_mime_type;
-
-	if (g_cancellable_is_cancelled (cancellable))
-		return NULL;
+	gboolean mime_part_handled = FALSE;
 
 	if (mime_type)
 		as_mime_type = g_ascii_strdown (mime_type, -1);
@@ -491,9 +487,10 @@ e_mail_parser_parse_part_as (EMailParser *parser,
 	if (as_mime_type)
 		g_free (as_mime_type);
 
-	if (!parsers) {
-		return e_mail_parser_wrap_as_attachment (
-			parser, part, NULL, part_id, cancellable);
+	if (parsers == NULL) {
+		e_mail_parser_wrap_as_attachment (
+			parser, part, part_id, out_mail_parts);
+		return TRUE;
 	}
 
 	for (iter = parsers->head; iter; iter = iter->next) {
@@ -503,19 +500,20 @@ e_mail_parser_parse_part_as (EMailParser *parser,
 		if (!extension)
 			continue;
 
-		part_list = e_mail_parser_extension_parse (
-			extension, parser, part, part_id, cancellable);
+		mime_part_handled = e_mail_parser_extension_parse (
+			extension, parser, part, part_id,
+			cancellable, out_mail_parts);
 
-		if (part_list)
+		if (mime_part_handled)
 			break;
 	}
 
-	return part_list;
+	return mime_part_handled;
 }
 
-GSList *
+void
 e_mail_parser_error (EMailParser *parser,
-                     GCancellable *cancellable,
+                     GQueue *out_mail_parts,
                      const gchar *format,
                      ...)
 {
@@ -525,8 +523,9 @@ e_mail_parser_error (EMailParser *parser,
 	gchar *uri;
 	va_list ap;
 
-	g_return_val_if_fail (E_IS_MAIL_PARSER (parser), NULL);
-	g_return_val_if_fail (format != NULL, NULL);
+	g_return_if_fail (E_IS_MAIL_PARSER (parser));
+	g_return_if_fail (out_mail_parts != NULL);
+	g_return_if_fail (format != NULL);
 
 	va_start (ap, format);
 	errmsg = g_strdup_vprintf (format, ap);
@@ -551,7 +550,7 @@ e_mail_parser_error (EMailParser *parser,
 	g_free (uri);
 	g_object_unref (part);
 
-	return g_slist_append (NULL, mail_part);
+	g_queue_push_tail (out_mail_parts, mail_part);
 }
 
 static void
@@ -581,14 +580,14 @@ load_attachment_idle (EAttachment *attachment)
 	return FALSE;
 }
 
-GSList *
+void
 e_mail_parser_wrap_as_attachment (EMailParser *parser,
                                   CamelMimePart *part,
-                                  GSList *parts,
                                   GString *part_id,
-                                  GCancellable *cancellable)
+                                  GQueue *parts_queue)
 {
 	EMailPartAttachment *empa;
+	EMailPart *first_part;
 	const gchar *snoop_mime_type, *cid;
 	GQueue *extensions;
 	CamelContentType *ct;
@@ -644,7 +643,12 @@ e_mail_parser_wrap_as_attachment (EMailParser *parser,
 		e_mail_part_is_inline (part, extensions));
 	empa->snoop_mime_type = snoop_mime_type;
 	empa->attachment = e_attachment_new ();
-	empa->attachment_view_part_id = parts ? g_strdup (E_MAIL_PART (parts->data)->id) : NULL;
+
+	first_part = g_queue_peek_head (parts_queue);
+	if (first_part != NULL) {
+		empa->attachment_view_part_id = g_strdup (first_part->id);
+		first_part->is_hidden = TRUE;
+	}
 
 	cid = camel_mime_part_get_content_id (part);
 	if (cid)
@@ -692,13 +696,10 @@ e_mail_parser_wrap_as_attachment (EMailParser *parser,
 		g_object_unref (fileinfo);
 	}
 
-	if (parts && parts->data) {
-		E_MAIL_PART (parts->data)->is_hidden = TRUE;
-	}
-
 	g_string_truncate (part_id, part_id_len);
 
-	return g_slist_prepend (parts, empa);
+	/* Push to head, not tail. */
+	g_queue_push_head (parts_queue, empa);
 }
 
 CamelSession *