From 0ec2b6ca60f4e029177919638487ba5d438d260b Mon Sep 17 00:00:00 2001
From: "Alexander A. Klimov" <alexander.klimov@icinga.com>
Date: Fri, 26 Mar 2021 12:17:16 +0100
Subject: [PATCH] Return ctx.Err() on ctx.Done()

---
 pkg/com/bulker.go     | 4 ++--
 pkg/driver/driver.go  | 2 +-
 pkg/icingadb/delta.go | 4 ++--
 pkg/retry/retry.go    | 4 +++-
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/pkg/com/bulker.go b/pkg/com/bulker.go
index 3118e80a..aebe4ecc 100644
--- a/pkg/com/bulker.go
+++ b/pkg/com/bulker.go
@@ -50,7 +50,7 @@ func (b *Bulker) run(ch <-chan contracts.Entity, count int) {
 
 				bufCh <- v
 			case <-ctx.Done():
-				return nil
+				return ctx.Err()
 			}
 		}
 	})
@@ -74,7 +74,7 @@ func (b *Bulker) run(ch <-chan contracts.Entity, count int) {
 				case <-timeout:
 					drain = false
 				case <-ctx.Done():
-					return nil
+					return ctx.Err()
 				}
 			}
 
diff --git a/pkg/driver/driver.go b/pkg/driver/driver.go
index 033a3907..d32f207d 100644
--- a/pkg/driver/driver.go
+++ b/pkg/driver/driver.go
@@ -46,7 +46,7 @@ func (d Driver) Open(dsn string) (c driver.Conn, err error) {
 		select {
 		case <-ctx.Done():
 			// Context canceled.
-			return
+			return nil, ctx.Err()
 		case <-time.After(sleep):
 			// Wait for backoff duration and continue.
 		}
diff --git a/pkg/icingadb/delta.go b/pkg/icingadb/delta.go
index a9e9d5a1..46686dfd 100644
--- a/pkg/icingadb/delta.go
+++ b/pkg/icingadb/delta.go
@@ -80,7 +80,7 @@ func (delta *Delta) start(ctx context.Context, actualCh, desiredCh <-chan contra
 
 				cnt.Inc()
 			case <-ctx.Done():
-				return nil
+				return ctx.Err()
 			}
 		}
 	})
@@ -116,7 +116,7 @@ func (delta *Delta) start(ctx context.Context, actualCh, desiredCh <-chan contra
 
 				cnt.Inc()
 			case <-ctx.Done():
-				return nil
+				return ctx.Err()
 			}
 		}
 	})
diff --git a/pkg/retry/retry.go b/pkg/retry/retry.go
index b3efe46e..4f7cbd7a 100644
--- a/pkg/retry/retry.go
+++ b/pkg/retry/retry.go
@@ -30,7 +30,9 @@ func WithBackoff(ctx context.Context, retryableFunc RetryableFunc, retryable IsR
 		select {
 		case <-ctx.Done():
 			// Context canceled. Return last known error.
-			// TODO(el): Return ctx.Err() if err is nil?
+			if err == nil {
+				err = ctx.Err()
+			}
 			return
 		case <-time.After(sleep):
 			// Wait for backoff duration and continue.