From 7eb5e8a08ac1f53cf52f327cb6e2fea9cb12c110 Mon Sep 17 00:00:00 2001
From: beorn7 <beorn@soundcloud.com>
Date: Sat, 29 Sep 2018 10:43:39 +0200
Subject: [PATCH] Drain the desc channel after registering

This avoids leaking goroutines.

Signed-off-by: beorn7 <beorn@soundcloud.com>
---
 prometheus/registry.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/prometheus/registry.go b/prometheus/registry.go
index 2c0b908..8d274e0 100644
--- a/prometheus/registry.go
+++ b/prometheus/registry.go
@@ -273,7 +273,12 @@ func (r *Registry) Register(c Collector) error {
 		close(descChan)
 	}()
 	r.mtx.Lock()
-	defer r.mtx.Unlock()
+	defer func() {
+		// Drain channel in case of premature return to not leak a goroutine.
+		for range descChan {
+		}
+		r.mtx.Unlock()
+	}()
 	// Conduct various tests...
 	for desc := range descChan {