From d7ad13d929a956999f8d4ff30fcbbebe1d161132 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Fri, 3 Mar 2023 10:45:00 +0000
Subject: [PATCH] bucket: add Join function for a simplified path.Join

---
 lib/bucket/bucket.go      | 13 +++++++++++++
 lib/bucket/bucket_test.go | 21 +++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lib/bucket/bucket.go b/lib/bucket/bucket.go
index 13217f0da..44aac0bb3 100644
--- a/lib/bucket/bucket.go
+++ b/lib/bucket/bucket.go
@@ -29,6 +29,19 @@ func Split(absPath string) (bucket, bucketPath string) {
 	return absPath[:slash], absPath[slash+1:]
 }
 
+// Join path1 and path2
+//
+// Like path.Join but does not clean the path - useful to preserve trailing /
+func Join(path1, path2 string) string {
+	if path1 == "" {
+		return path2
+	}
+	if path2 == "" {
+		return path1
+	}
+	return strings.TrimSuffix(path1, "/") + "/" + strings.TrimPrefix(path2, "/")
+}
+
 // Cache stores whether buckets are available and their IDs
 type Cache struct {
 	mu       sync.Mutex      // mutex to protect created and deleted
diff --git a/lib/bucket/bucket_test.go b/lib/bucket/bucket_test.go
index c178a37f9..1a36ea300 100644
--- a/lib/bucket/bucket_test.go
+++ b/lib/bucket/bucket_test.go
@@ -2,6 +2,7 @@ package bucket
 
 import (
 	"errors"
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -24,6 +25,26 @@ func TestSplit(t *testing.T) {
 	}
 }
 
+func TestJoin(t *testing.T) {
+	for _, test := range []struct {
+		in1, in2 string
+		want     string
+	}{
+		{in1: "", in2: "", want: ""},
+		{in1: "in1", in2: "", want: "in1"},
+		{in1: "", in2: "in2", want: "in2"},
+		{in1: "in1", in2: "in2", want: "in1/in2"},
+		{in1: "in1/", in2: "in2", want: "in1/in2"},
+		{in1: "in1", in2: "/in2", want: "in1/in2"},
+		{in1: "in1", in2: "in2/", want: "in1/in2/"},
+		{in1: "/in1", in2: "/in2", want: "/in1/in2"},
+		{in1: "/in1", in2: "../in2", want: "/in1/../in2"},
+	} {
+		got := Join(test.in1, test.in2)
+		assert.Equal(t, test.want, got, fmt.Sprintf("in1=%q, in2=%q", test.in1, test.in2))
+	}
+}
+
 func TestCache(t *testing.T) {
 	c := NewCache()
 	errBoom := errors.New("boom")