degesch: fix handling of buffer collisions

degesch.c

@@ -2669,20 +2669,23 @@ buffer_merge (struct app_context *ctx,
 	size_t n = 0;
 	for (struct buffer_line *iter = start; iter; iter = iter->next)
 		n++;
+	struct buffer_line *tail = merged->lines_tail;
 
-	// Append the merged part to current lines in the buffer
+	// Cut them from the original buffer
+	if (start == merged->lines)
+		merged->lines = NULL;
+	else if (start->prev)
+		start->prev->next = NULL;
+	if (start == merged->lines_tail)
+		merged->lines_tail = start->prev;
+	merged->lines_count -= n;
+
+	// And append them to current lines in the buffer
 	buffer->lines_tail->next = start;
 	start->prev = buffer->lines_tail;
-
+	buffer->lines_tail = tail;
-	buffer->lines_tail = merged->lines_tail;
 	buffer->lines_count += n;
 
-	// And remove it from the original buffer
-	if (start == merged->lines_tail)
-		if (!(merged->lines_tail = start->prev))
-			merged->lines = NULL;
-	merged->lines_count -= n;
-
 	// XXX: we don't want to log this entry to a file
 	buffer_send_status (ctx, buffer, "End of merged content");
 }
@@ -2691,39 +2694,20 @@ static void
 buffer_rename (struct app_context *ctx,
 	struct buffer *buffer, const char *new_name)
 {
-	hard_assert (buffer->type == BUFFER_PM);
+	struct buffer *collision = str_map_find (&ctx->buffers_by_name, new_name);
+	if (collision == buffer)
+		return;
 
-	// FIXME: this will never find anything as we are being sent
+	hard_assert (!collision);
-	//   the full buffer name, including the server name;
-	//   searching in "buffers_by_name" won't do it either,
-	//   we seem to need more information to properly handle this
-	struct buffer *collision =
-		str_map_find (&buffer->server->irc_buffer_map, new_name);
-	if (collision)
-	{
-		// TODO: use full weechat-style buffer names
-		//   to prevent name collisions with the global buffer
-		hard_assert (collision->type == BUFFER_PM);
 
-		// When there's a collision, there's not much else we can do
+	str_map_set (&ctx->buffers_by_name, buffer->name, NULL);
-		// other than somehow trying to merge them
+	str_map_set (&ctx->buffers_by_name, new_name, buffer);
-		buffer_merge (ctx, collision, buffer);
-		if (ctx->current_buffer == buffer)
-			buffer_activate (ctx, collision);
-		buffer_remove (ctx, buffer);
-	}
-	else
-	{
-		// Otherwise we just rename the buffer and that's it
-		str_map_set (&ctx->buffers_by_name, buffer->name, NULL);
-		str_map_set (&ctx->buffers_by_name, new_name, buffer);
 
-		free (buffer->name);
+	free (buffer->name);
-		buffer->name = xstrdup (new_name);
+	buffer->name = xstrdup (new_name);
 
-		// We might have renamed the current buffer
+	// We might have renamed the current buffer
-		refresh_prompt (ctx);
+	refresh_prompt (ctx);
-	}
 }
 
 static void
@@ -4373,6 +4357,27 @@ irc_handle_mode (struct server *s, const struct irc_message *msg)
 	refresh_prompt (s->ctx);
 }
 
+static struct buffer *
+irc_handle_buffer_collision (struct server *s,
+	struct buffer *buffer, const char *new_name)
+{
+	struct buffer *collision = str_map_find (&s->irc_buffer_map, new_name);
+	if (!collision)
+		return buffer;
+
+	// TODO: use full weechat-style buffer names
+	//   to prevent name collisions with the global buffer
+	hard_assert (collision->type == buffer->type);
+
+	// When there's a collision, there's not much else we can do
+	// other than somehow try to merge them
+	buffer_merge (s->ctx, collision, buffer);
+	if (s->ctx->current_buffer == buffer)
+		buffer_activate (s->ctx, collision);
+	buffer_remove (s->ctx, buffer);
+	return collision;
+}
+
 static void
 irc_handle_nick (struct server *s, const struct irc_message *msg)
 {
@@ -4402,12 +4407,6 @@ irc_handle_nick (struct server *s, const struct irc_message *msg)
 		str_map_find (&s->irc_buffer_map, user->nickname);
 	if (pm_buffer)
 	{
-		if (!lexicographically_identical)
-		{
-			str_map_set (&s->irc_buffer_map, new_nickname, pm_buffer);
-			str_map_set (&s->irc_buffer_map, user->nickname, NULL);
-		}
-
 		char *who = irc_is_this_us (s, msg->prefix)
 			? irc_to_utf8 (s->ctx, msg->prefix)
 			: NULL;
@@ -4415,6 +4414,21 @@ irc_handle_nick (struct server *s, const struct irc_message *msg)
 			.who    = who,
 			.object = irc_to_utf8 (s->ctx, new_nickname));
 
+		if (!lexicographically_identical)
+		{
+			// XXX: this code seems a bit ugly (but also necessary)
+			user = user_ref (user);
+
+			pm_buffer = irc_handle_buffer_collision
+				(s, pm_buffer, new_nickname);
+
+			user_unref (pm_buffer->user);
+			pm_buffer->user = user;
+
+			str_map_set (&s->irc_buffer_map, user->nickname, NULL);
+			str_map_set (&s->irc_buffer_map, new_nickname, pm_buffer);
+		}
+
 		char *x = xstrdup_printf ("%s.%s", s->name, new_nickname);
 		buffer_rename (s->ctx, pm_buffer, x);
 		free (x);
@@ -4453,8 +4467,9 @@ irc_handle_nick (struct server *s, const struct irc_message *msg)
 	// Finally rename the user
 	if (!lexicographically_identical)
 	{
-		str_map_set (&s->irc_users, new_nickname, user_ref (user));
+		// NOTE: this doesn't dereference anything
 		str_map_set (&s->irc_users, user->nickname, NULL);
+		str_map_set (&s->irc_users, new_nickname, user);
 	}
 
 	free (user->nickname);