From 915ba01ff1388028a85156feb08e9296c356a696 Mon Sep 17 00:00:00 2001
From: Ronan Pigott <rpigott@berkeley.edu>
Date: Fri, 15 Jan 2021 13:44:22 -0700
Subject: [PATCH] config/output: correct refresh rate rounding error

---
 sway/config/output.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sway/config/output.c b/sway/config/output.c
index b59cabd4..c9ec6745 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -237,7 +237,10 @@ struct output_config *store_output_config(struct output_config *oc) {
 
 static void set_mode(struct wlr_output *output, int width, int height,
 		float refresh_rate, bool custom) {
-	int mhz = (int)(refresh_rate * 1000);
+	// Not all floating point integers can be represented exactly
+	// as (int)(1000 * mHz / 1000.f)
+	// round() the result to avoid any error
+	int mhz = (int)round(refresh_rate * 1000);
 
 	if (wl_list_empty(&output->modes) || custom) {
 		sway_log(SWAY_DEBUG, "Assigning custom mode to %s", output->name);