From 1174e97b309e37a33a2850cfc25fef1ad95b6e8f Mon Sep 17 00:00:00 2001
From: Michael Eischer <michael.eischer@fau.de>
Date: Sun, 14 Jun 2026 21:38:09 +0200
Subject: [PATCH] restic: speed up repository config initialization in tests

Avoid redundant polynomial generation, which takes a millisecond or so.
---
 internal/repository/repository.go |  5 +----
 internal/restic/config.go         | 12 ++++++++----
 internal/restic/config_test.go    |  2 +-
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/internal/repository/repository.go b/internal/repository/repository.go
index 35f5c78f5..889c76049 100644
--- a/internal/repository/repository.go
+++ b/internal/repository/repository.go
@@ -919,13 +919,10 @@ func (r *Repository) Init(ctx context.Context, version uint, password string, ch
 		return err
 	}
 
-	cfg, err := restic.CreateConfig(version)
+	cfg, err := restic.CreateConfig(version, chunkerPolynomial)
 	if err != nil {
 		return err
 	}
-	if chunkerPolynomial != nil {
-		cfg.ChunkerPolynomial = *chunkerPolynomial
-	}
 
 	return r.init(ctx, password, cfg)
 }
diff --git a/internal/restic/config.go b/internal/restic/config.go
index 8af09c908..4c6c97a08 100644
--- a/internal/restic/config.go
+++ b/internal/restic/config.go
@@ -28,15 +28,19 @@ const StableRepoVersion = 2
 
 // CreateConfig creates a config file with a randomly selected polynomial and
 // ID.
-func CreateConfig(version uint) (Config, error) {
+func CreateConfig(version uint, pol *chunker.Pol) (Config, error) {
 	var (
 		err error
 		cfg Config
 	)
 
-	cfg.ChunkerPolynomial, err = chunker.RandomPolynomial()
-	if err != nil {
-		return Config{}, errors.Wrap(err, "chunker.RandomPolynomial")
+	if pol == nil {
+		cfg.ChunkerPolynomial, err = chunker.RandomPolynomial()
+		if err != nil {
+			return Config{}, errors.Wrap(err, "chunker.RandomPolynomial")
+		}
+	} else {
+		cfg.ChunkerPolynomial = *pol
 	}
 
 	cfg.ID = NewRandomID().String()
diff --git a/internal/restic/config_test.go b/internal/restic/config_test.go
index 5a7f6b0ae..54d3db2fc 100644
--- a/internal/restic/config_test.go
+++ b/internal/restic/config_test.go
@@ -43,7 +43,7 @@ func TestConfig(t *testing.T) {
 		return restic.ID{}, nil
 	}
 
-	cfg1, err := restic.CreateConfig(restic.MaxRepoVersion)
+	cfg1, err := restic.CreateConfig(restic.MaxRepoVersion, nil)
 	rtest.OK(t, err)
 
 	err = restic.SaveConfig(context.TODO(), saver{save}, cfg1)