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, 45 insertions, 55 deletions

diff --git a/em-format/e-mail-parser-multipart-signed.c b/em-format/e-mail-parser-multipart-signed.c
index b7d395ab05..60fac35c7f 100644
--- a/em-format/e-mail-parser-multipart-signed.c
+++ b/em-format/e-mail-parser-multipart-signed.c
@@ -28,6 +28,7 @@
 
 #include <glib/gi18n-lib.h>
 #include <camel/camel.h>
+#include <libedataserver/libedataserver.h>
 
 typedef struct _EMailParserMultipartSigned {
 	GObject parent;
@@ -56,33 +57,30 @@ static const gchar * parser_mime_types[] = { "multipart/signed",
 					    "application/pgp-signature",
 					    NULL };
 
-static GSList *
+static gboolean
 empe_mp_signed_parse (EMailParserExtension *extension,
                       EMailParser *parser,
                       CamelMimePart *part,
                       GString *part_id,
-                      GCancellable *cancellable)
+                      GCancellable *cancellable,
+                      GQueue *out_mail_parts)
 {
 	CamelMimePart *cpart;
 	CamelMultipartSigned *mps;
 	CamelCipherContext *cipher = NULL;
 	CamelSession *session;
 	guint32 validity_type;
-	GSList *parts;
 	CamelCipherValidity *valid;
 	GError *local_error = NULL;
 	gint i, nparts, len;
 	gboolean secured;
 
-	if (g_cancellable_is_cancelled (cancellable))
-		return NULL;
-
 	/* If the part is application/pgp-signature sub-part then skip it. */
 	if (!CAMEL_IS_MULTIPART (part)) {
 		CamelContentType *ct;
 		ct = camel_mime_part_get_content_type (CAMEL_MIME_PART (part));
 		if (camel_content_type_is (ct, "application", "pgp-signature")) {
-			return g_slist_alloc ();
+			return TRUE;
 		}
 	}
 
@@ -92,18 +90,16 @@ empe_mp_signed_parse (EMailParserExtension *extension,
 		cpart = camel_multipart_get_part (
 			(CamelMultipart *) mps,
 		CAMEL_MULTIPART_SIGNED_CONTENT)) == NULL) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Could not parse MIME message. "
 			"Displaying as source."));
+		e_mail_parser_parse_part_as (
+			parser, part, part_id,
+			"application/vnd.evolution.source",
+			cancellable, out_mail_parts);
 
-		parts = g_slist_concat (
-			parts,
-			e_mail_parser_parse_part_as (
-				parser, part, part_id,
-				"application/vnd.evolution.source",
-				cancellable));
-		return parts;
+		return TRUE;
 	}
 
 	session = e_mail_parser_get_session (parser);
@@ -127,95 +123,89 @@ empe_mp_signed_parse (EMailParserExtension *extension,
 	}
 
 	if (cipher == NULL) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Unsupported signature format"));
+		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;
 	}
 
 	valid = camel_cipher_context_verify_sync (
 		cipher, part, cancellable, &local_error);
 
 	if (local_error != NULL) {
-		parts = e_mail_parser_error (
-			parser, cancellable,
+		e_mail_parser_error (
+			parser, out_mail_parts,
 			_("Error verifying signature: %s"),
 			local_error->message);
+		e_mail_parser_parse_part_as (
+			parser, part, part_id, "multipart/mixed",
+			cancellable, out_mail_parts);
 
+		g_object_unref (cipher);
 		g_error_free (local_error);
 
-		parts = g_slist_concat (
-			parts,
-			e_mail_parser_parse_part_as (
-				parser, part, part_id,
-				"multipart/mixed", cancellable));
-
-		g_object_unref (cipher);
-		return parts;
+		return TRUE;
 	}
 
 	nparts = camel_multipart_get_number (CAMEL_MULTIPART (mps));
 	secured = FALSE;
 	len = part_id->len;
-	parts = NULL;
 	for (i = 0; i < nparts; i++) {
+		GQueue work_queue = G_QUEUE_INIT;
+		GList *head, *link;
 		CamelMimePart *subpart;
-		GSList *mail_parts, *iter;
+
 		subpart = camel_multipart_get_part (CAMEL_MULTIPART (mps), i);
 
 		g_string_append_printf (part_id, ".signed.%d", i);
 
-		mail_parts = e_mail_parser_parse_part (
-			parser, subpart, part_id, cancellable);
+		e_mail_parser_parse_part (
+			parser, subpart, part_id, cancellable, &work_queue);
 
 		g_string_truncate (part_id, len);
 
 		if (!secured)
 			secured = e_mail_part_is_secured (subpart);
 
-		for (iter = mail_parts; iter; iter = iter->next) {
-			EMailPart *mail_part;
+		head = g_queue_peek_head_link (&work_queue);
 
-			mail_part = iter->data;
-			if (!mail_part)
-				continue;
+		for (link = head; link != NULL; link = g_list_next (link)) {
+			EMailPart *mail_part = link->data;
 
 			e_mail_part_update_validity (
 				mail_part, valid,
 				validity_type | E_MAIL_PART_VALIDITY_SIGNED);
 		}
 
-		parts = g_slist_concat (parts, mail_parts);
+		e_queue_transfer (&work_queue, out_mail_parts);
 	}
 
 	/* Add a widget with details about the encryption, but only when
-		* the encrypted isn't itself secured, in that case it has created
-		* the button itself */
+	 * the encrypted isn't itself secured, in that case it has created
+	 * the button itself. */
 	if (!secured) {
-		GSList *button;
+		GQueue work_queue = G_QUEUE_INIT;
 		EMailPart *mail_part;
+
 		g_string_append (part_id, ".signed.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,
 				validity_type | E_MAIL_PART_VALIDITY_SIGNED);
-		}
 
-		parts = g_slist_concat (parts, button);
+		e_queue_transfer (&work_queue, out_mail_parts);
 
 		g_string_truncate (part_id, len);
 	}
@@ -224,7 +214,7 @@ empe_mp_signed_parse (EMailParserExtension *extension,
 
 	g_object_unref (cipher);
 
-	return parts;
+	return TRUE;
 }
 
 static const gchar **