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, 43 insertions, 52 deletions

diff --git a/em-format/e-mail-parser-multipart-encrypted.c b/em-format/e-mail-parser-multipart-encrypted.c
index db417fabbf..fedef393ef 100644
--- a/em-format/e-mail-parser-multipart-encrypted.c
+++ b/em-format/e-mail-parser-multipart-encrypted.c
@@ -28,6 +28,7 @@
 
 #include <glib/gi18n-lib.h>
 #include <camel/camel.h>
+#include <libedataserver/libedataserver.h>
 
 typedef struct _EMailParserMultipartEncrypted {
 	GObject parent;
@@ -54,56 +55,50 @@ G_DEFINE_TYPE_EXTENDED (
 
 static const gchar * parser_mime_types[] = { "multipart/encrypted", NULL };
 
-static GSList *
+static gboolean
 empe_mp_encrypted_parse (EMailParserExtension *extension,
                          EMailParser *parser,
                          CamelMimePart *part,
                          GString *part_id,
-                         GCancellable *cancellable)
+                         GCancellable *cancellable,
+                         GQueue *out_mail_parts)
 {
 	CamelCipherContext *context;
 	const gchar *protocol;
 	CamelMimePart *opart;
 	CamelCipherValidity *valid;
 	CamelMultipartEncrypted *mpe;
+	GQueue work_queue = G_QUEUE_INIT;
+	GList *head, *link;
 	GError *local_error = NULL;
-	GSList *parts;
 	gint len;
-	GSList *iter;
-
-	if (g_cancellable_is_cancelled (cancellable))
-		return NULL;
 
 	mpe = (CamelMultipartEncrypted *) camel_medium_get_content ((CamelMedium *) part);
 	if (!CAMEL_IS_MULTIPART_ENCRYPTED (mpe)) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Could not parse MIME message. "
 			"Displaying as source."));
-		parts = g_slist_concat (
-			parts,
-			e_mail_parser_parse_part_as (
-				parser, part, part_id,
-				"application/vnd.evolution/source",
-				cancellable));
-
-		return parts;
+		e_mail_parser_parse_part_as (
+			parser, part, part_id,
+			"application/vnd.evolution/source",
+			cancellable, out_mail_parts);
+
+		return TRUE;
 	}
 
 	/* Currently we only handle RFC2015-style PGP encryption. */
 	protocol = camel_content_type_param (
 		((CamelDataWrapper *) mpe)->mime_type, "protocol");
 	if (!protocol || g_ascii_strcasecmp (protocol, "application/pgp-encrypted") != 0) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Unsupported encryption type for multipart/encrypted"));
+		e_mail_parser_parse_part_as (
+			parser, part, part_id, "multipart/mixed",
+			cancellable, out_mail_parts);
 
-		parts = g_slist_concat (
-			parts,
-			e_mail_parser_parse_part_as (
-				parser, part, part_id,
-				"multipart/mixed", cancellable));
-		return parts;
+		return TRUE;
 	}
 
 	context = camel_gpg_context_new (e_mail_parser_get_session (parser));
@@ -115,40 +110,34 @@ empe_mp_encrypted_parse (EMailParserExtension *extension,
 	e_mail_part_preserve_charset_in_content_type (part, opart);
 
 	if (local_error != NULL) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Could not parse PGP/MIME message: %s"),
 			local_error->message);
-
-		g_error_free (local_error);
-
-		parts = g_slist_concat (
-			parts,
-			e_mail_parser_parse_part_as (
-				parser, part, part_id,
-				"multipart/mixed", cancellable));
+		e_mail_parser_parse_part_as (
+			parser, part, part_id, "multipart/mixed",
+			cancellable, out_mail_parts);
 
 		g_object_unref (opart);
 		g_object_unref (context);
+		g_error_free (local_error);
 
-		return parts;
+		return TRUE;
 	}
 
 	len = part_id->len;
 	g_string_append (part_id, ".encrypted");
 
-	parts = e_mail_parser_parse_part (
-		parser, opart, part_id, cancellable);
+	e_mail_parser_parse_part (
+		parser, opart, part_id, cancellable, &work_queue);
 
 	g_string_truncate (part_id, len);
 
-	/* Update validity of all encrypted sub-parts */
-	for (iter = parts; iter; iter = iter->next) {
-		EMailPart *mail_part;
+	head = g_queue_peek_head_link (&work_queue);
 
-		mail_part = iter->data;
-		if (!mail_part)
-			continue;
+	/* Update validity of all encrypted sub-parts */
+	for (link = head; link != NULL; link = g_list_next (link)) {
+		EMailPart *mail_part = link->data;
 
 		e_mail_part_update_validity (
 			mail_part, valid,
@@ -156,28 +145,30 @@ empe_mp_encrypted_parse (EMailParserExtension *extension,
 			E_MAIL_PART_VALIDITY_PGP);
 	}
 
+	e_queue_transfer (&work_queue, out_mail_parts);
+
 	/* Add a widget with details about the encryption, but only when
 	 * the decrypted part isn't itself secured, in that case it has
 	 * created the button itself. */
 	if (!e_mail_part_is_secured (opart)) {
-		GSList *button;
 		EMailPart *mail_part;
+
 		g_string_append (part_id, ".encrypted.button");
 
-		button = e_mail_parser_parse_part_as (
+		e_mail_parser_parse_part_as (
 			parser, part, part_id,
 			"application/vnd.evolution.widget.secure-button",
-			cancellable);
-		if (button && button->data) {
-			mail_part = button->data;
+			cancellable, &work_queue);
+
+		mail_part = g_queue_peek_head (&work_queue);
 
+		if (mail_part != NULL)
 			e_mail_part_update_validity (
 				mail_part, valid,
 				E_MAIL_PART_VALIDITY_ENCRYPTED |
 				E_MAIL_PART_VALIDITY_PGP);
-		}
 
-		parts = g_slist_concat (parts, button);
+		e_queue_transfer (&work_queue, out_mail_parts);
 
 		g_string_truncate (part_id, len);
 	}
@@ -188,7 +179,7 @@ empe_mp_encrypted_parse (EMailParserExtension *extension,
 	g_object_unref (opart);
 	g_object_unref (context);
 
-	return parts;
+	return TRUE;
 }
 
 static const gchar **