From 3910926c2666c8dafd193d6dd485cc7527d8ecbf Mon Sep 17 00:00:00 2001
From: Pooya Parsa <pooya@pi0.io>
Date: Fri, 15 Mar 2024 23:48:39 +0100
Subject: [PATCH] fix(joinRelativeURL): handle base with protocol (#222)

---
 src/utils.ts      | 6 +++++-
 test/join.test.ts | 8 ++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/utils.ts b/src/utils.ts
index fafa927..ffe91e6 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -14,6 +14,7 @@ const PROTOCOL_RELATIVE_REGEX = /^([/\\]\s*){2,}[^/\\]/;
 const PROTOCOL_SCRIPT_RE = /^[\s\0]*(blob|data|javascript|vbscript):$/i;
 const TRAILING_SLASH_RE = /\/$|\/\?|\/#/;
 const JOIN_LEADING_SLASH_RE = /^\.?\//;
+const JOIN_SEGMENT_SPLIT_RE = /(?<!\/)\/(?!\/)/;
 
 /**
  * Check if a path starts with `./` or `../`.
@@ -355,11 +356,14 @@ export function joinRelativeURL(..._input: string[]): string {
     if (!i || i === "/") {
       continue;
     }
-    for (const s of i.split("/")) {
+    for (const s of i.split(JOIN_SEGMENT_SPLIT_RE)) {
       if (!s || s === ".") {
         continue;
       }
       if (s === "..") {
+        if (segments.length === 1 && hasProtocol(segments[0])) {
+          continue;
+        }
         segments.pop();
         segmentsDepth--;
         continue;
diff --git a/test/join.test.ts b/test/join.test.ts
index f5ae57d..aae33c4 100644
--- a/test/join.test.ts
+++ b/test/join.test.ts
@@ -16,6 +16,10 @@ const joinURLTests = [
   { input: ["/", "./foo"], out: "/foo" },
   { input: ["/", "./foo/"], out: "/foo/" },
   { input: ["/", "./foo", "bar"], out: "/foo/bar" },
+  {
+    input: ["https://google.com/", "./foo", "/bar"],
+    out: "https://google.com/foo/bar",
+  },
 ] as const;
 
 describe("joinURL", () => {
@@ -42,6 +46,10 @@ describe("joinRelativeURL", () => {
     { input: ["../a", "../../../b"], out: "../../b" },
     { input: ["../a", "../../../../b"], out: "../../../b" },
     { input: ["../a/", "../b"], out: "b" },
+    {
+      input: ["https://google.com/", "../foo"],
+      out: "https://google.com/foo",
+    },
   ];
 
   for (const t of relativeTests) {