IRCv3: Add support for the msgid specification

Testing Done:
Connected to my local ergo sent some messages and verified the id's were stored in `history.db` and that they matched what the server sent that I verified via `ngrep`.

Bugs closed: PIDGIN-17739

Reviewed at https://reviews.imfreedom.org/r/2218/

3 files changed, 43 insertions, 4 deletions

diff --git a/libpurple/protocols/ircv3/README.md b/libpurple/protocols/ircv3/README.md
index 3fa2c1fa5a..8df607539c 100644
--- a/libpurple/protocols/ircv3/README.md
+++ b/libpurple/protocols/ircv3/README.md
@@ -19,3 +19,4 @@ us know!
 * cap-notify
 * sasl (right now just PLAIN works)
 * message-tags
+* msgid
diff --git a/libpurple/protocols/ircv3/purpleircv3capabilities.c b/libpurple/protocols/ircv3/purpleircv3capabilities.c
index 35ac8c165c..44685ce91c 100644
--- a/libpurple/protocols/ircv3/purpleircv3capabilities.c
+++ b/libpurple/protocols/ircv3/purpleircv3capabilities.c
@@ -101,6 +101,18 @@ purple_ircv3_capabilities_add(PurpleIRCv3Capabilities *capabilities,
 }
 
 /******************************************************************************
+ * Callbacks
+ *****************************************************************************/
+static void
+ircv3_capabilities_message_tags_ack_cb(PurpleIRCv3Capabilities *capabilities,
+                                       G_GNUC_UNUSED const char *capability,
+                                       G_GNUC_UNUSED gpointer data)
+{
+	/* We have message tags so add the stuff we support that depends on it. */
+	purple_ircv3_capabilities_lookup_and_request(capabilities, "msgid");
+}
+
+/******************************************************************************
  * PurpleIRCv3Capabilities Implementation
  *****************************************************************************/
 static void
@@ -133,7 +145,13 @@ purple_ircv3_capabilities_default_ready_cb(PurpleIRCv3Capabilities *capabilities
 	/* message-tags is used for a lot of stuff so we need to tell everyone we
 	 * do in fact support it.
 	 */
-	purple_ircv3_capabilities_lookup_and_request(capabilities, "message-tags");
+	if(purple_ircv3_capabilities_lookup_and_request(capabilities,
+	                                                "message-tags"))
+	{
+		g_signal_connect(capabilities, "ack::message-tags",
+		                 G_CALLBACK(ircv3_capabilities_message_tags_ack_cb),
+		                 NULL);
+	}
 }
 
 /******************************************************************************
diff --git a/libpurple/protocols/ircv3/purpleircv3messagehandlers.c b/libpurple/protocols/ircv3/purpleircv3messagehandlers.c
index 88b1f5ba1c..08d813f211 100644
--- a/libpurple/protocols/ircv3/purpleircv3messagehandlers.c
+++ b/libpurple/protocols/ircv3/purpleircv3messagehandlers.c
@@ -70,7 +70,7 @@ purple_ircv3_message_handler_ping(G_GNUC_UNUSED GHashTable *tags,
 }
 
 gboolean
-purple_ircv3_message_handler_privmsg(G_GNUC_UNUSED GHashTable *tags,
+purple_ircv3_message_handler_privmsg(GHashTable *tags,
                                      const char *source,
                                      const char *command,
                                      guint n_params,
@@ -86,6 +86,9 @@ purple_ircv3_message_handler_privmsg(G_GNUC_UNUSED GHashTable *tags,
 	PurpleConversationManager *conversation_manager = NULL;
 	PurpleMessage *message = NULL;
 	PurpleMessageFlags flags = PURPLE_MESSAGE_RECV;
+	GDateTime *dt = NULL;
+	gpointer raw_id = NULL;
+	const char *id = NULL;
 	const char *target = NULL;
 
 	if(n_params != 2) {
@@ -128,12 +131,29 @@ purple_ircv3_message_handler_privmsg(G_GNUC_UNUSED GHashTable *tags,
 		g_object_unref(conversation);
 	}
 
+	/* Grab the msgid if one was provided. */
+	if(g_hash_table_lookup_extended(tags, "msgid", NULL, &raw_id)) {
+		if(!purple_strempty(raw_id)) {
+			id = raw_id;
+		}
+	}
+
 	if(purple_strequal(command, "NOTICE")) {
 		flags |= PURPLE_MESSAGE_NOTIFY;
 	}
 
-	message = purple_message_new_incoming(account, source, params[1], flags,
-	                                      0);
+	dt = g_date_time_new_now_local();
+
+	message = g_object_new(
+		PURPLE_TYPE_MESSAGE,
+		"author", source,
+		"contents", params[1],
+		"flags", flags,
+		"id", id,
+		"timestamp", dt,
+		NULL);
+
+	g_date_time_unref(dt);
 
 	purple_conversation_write_message(conversation, message);