From fa717538ee52506cb84b94d2d27058e79772c454 Mon Sep 17 00:00:00 2001
From: Naftoli Gugenheim <98384+nafg@users.noreply.github.com>
Date: Sun, 21 Jul 2024 22:52:54 -0400
Subject: [PATCH] Restore 0.8.0 behavior of header values overriding earlier
 ones for the same key (#163)

Fixes #161
---
 requests/src/requests/Requester.scala | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/requests/src/requests/Requester.scala b/requests/src/requests/Requester.scala
index 7b4b158..e715dbe 100644
--- a/requests/src/requests/Requester.scala
+++ b/requests/src/requests/Requester.scala
@@ -10,6 +10,7 @@ import java.util.function.Supplier
 import java.util.zip.{GZIPInputStream, InflaterInputStream}
 
 import scala.collection.JavaConverters._
+import scala.collection.immutable.ListMap
 import scala.collection.mutable
 import scala.concurrent.{ExecutionException, Future}
 
@@ -241,7 +242,12 @@ case class Requester(verb: String,
             .map { case (k, v) => s"""$k="$v"""" }
             .mkString("; ")
           ))
-      val allHeadersFlat = allHeaders.toList.flatMap { case (k, v) => Seq(k, v) }
+      val lastOfEachHeader =
+        allHeaders.foldLeft(ListMap.empty[String, (String, String)]) {
+          case (acc, (k, v)) =>
+            acc.updated(k.toLowerCase, k -> v)
+        }
+      val headersKeyValueAlternating = lastOfEachHeader.values.toList.flatMap { case (k, v) => Seq(k, v) }
 
       val requestBodyInputStream = new PipedInputStream()
       val requestBodyOutputStream = new PipedOutputStream(requestBodyInputStream)
@@ -255,7 +261,7 @@ case class Requester(verb: String,
         HttpRequest.newBuilder()
           .uri(url1.toURI)
           .timeout(Duration.ofMillis(readTimeout))
-          .headers(allHeadersFlat: _*)
+          .headers(headersKeyValueAlternating: _*)
           .method(upperCaseVerb,
             (contentLengthHeader.headOption.map(_._2), compress) match {
               case (Some("0"), _)           => HttpRequest.BodyPublishers.noBody()