From d19702011a9725f7d1278fda75158ebe9c138d4c Mon Sep 17 00:00:00 2001
From: D Trombett <d@trombett.org>
Date: Tue, 12 Nov 2024 18:07:58 +0100
Subject: [PATCH] fix: range end is zero-indexed (#3826)

* fix: range end is zero-indexed

* tests: update tests for retry handler

(cherry picked from commit 2b81fbc845cb0f7e8a621674a3c7aa5c59642daa)
---
 lib/handler/retry-handler.js | 6 +++---
 test/interceptors/retry.js   | 5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/handler/retry-handler.js b/lib/handler/retry-handler.js
index e00e82faf08..5d1ccf00538 100644
--- a/lib/handler/retry-handler.js
+++ b/lib/handler/retry-handler.js
@@ -229,7 +229,7 @@ class RetryHandler {
         return false
       }
 
-      const { start, size, end = size } = contentRange
+      const { start, size, end = size - 1 } = contentRange
 
       assert(this.start === start, 'content-range mismatch')
       assert(this.end == null || this.end === end, 'content-range mismatch')
@@ -252,7 +252,7 @@ class RetryHandler {
           )
         }
 
-        const { start, size, end = size } = range
+        const { start, size, end = size - 1 } = range
         assert(
           start != null && Number.isFinite(start),
           'content-range mismatch'
@@ -266,7 +266,7 @@ class RetryHandler {
       // We make our best to checkpoint the body for further range headers
       if (this.end == null) {
         const contentLength = headers['content-length']
-        this.end = contentLength != null ? Number(contentLength) : null
+        this.end = contentLength != null ? Number(contentLength) - 1 : null
       }
 
       assert(Number.isFinite(this.start))
diff --git a/test/interceptors/retry.js b/test/interceptors/retry.js
index 6e6f997cafa..b510ddba6c0 100644
--- a/test/interceptors/retry.js
+++ b/test/interceptors/retry.js
@@ -253,14 +253,15 @@ test('Should handle 206 partial content', async t => {
   const server = createServer((req, res) => {
     if (x === 0) {
       t.ok(true, 'pass')
+      res.setHeader('content-length', '6')
       res.setHeader('etag', 'asd')
       res.write('abc')
       setTimeout(() => {
         res.destroy()
       }, 1e2)
     } else if (x === 1) {
-      t.deepStrictEqual(req.headers.range, 'bytes=3-')
-      res.setHeader('content-range', 'bytes 3-6/6')
+      t.deepStrictEqual(req.headers.range, 'bytes=3-5')
+      res.setHeader('content-range', 'bytes 3-5/6')
       res.setHeader('etag', 'asd')
       res.statusCode = 206
       res.end('def')