From f4d82f0ad6b10881c0831595ad0e957094892a45 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Mon, 21 Dec 2020 20:44:36 -0700
Subject: [PATCH] std.Progress: work around time going backwards

---
 lib/std/Progress.zig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/std/Progress.zig b/lib/std/Progress.zig
index ae9b1783be..6e683c673e 100644
--- a/lib/std/Progress.zig
+++ b/lib/std/Progress.zig
@@ -160,6 +160,9 @@ pub fn maybeRefresh(self: *Progress) void {
     if (now < self.initial_delay_ns) return;
     const held = self.update_lock.tryAcquire() orelse return;
     defer held.release();
+    // TODO I have observed this to happen sometimes. I think we need to follow Rust's
+    // lead and guarantee monotonically increasing times in the std lib itself.
+    if (now < self.prev_refresh_timestamp) return;
     if (now - self.prev_refresh_timestamp < self.refresh_rate_ns) return;
     return self.refreshWithHeldLock();
 }