From f7a3b5e0f7e5e127b97defa92a132fbf1b55cf15 Mon Sep 17 00:00:00 2001
From: Dmitriy Mozgovoy <robotshara@gmail.com>
Date: Wed, 23 Apr 2025 19:24:08 +0300
Subject: [PATCH] fix(headers): fixed support for setting multiple header
 values from an iterated source; (#6885)

---
 lib/core/AxiosHeaders.js       |  7 ++++++-
 test/helpers/retry.js          | 18 ++++++++++++++++++
 test/specs/formdata.spec.js    | 15 +++++++++------
 test/unit/core/AxiosHeaders.js | 22 ++++++++++++++++++++++
 4 files changed, 55 insertions(+), 7 deletions(-)
 create mode 100644 test/helpers/retry.js

diff --git a/lib/core/AxiosHeaders.js b/lib/core/AxiosHeaders.js
index 42a10ca..6744581 100644
--- a/lib/core/AxiosHeaders.js
+++ b/lib/core/AxiosHeaders.js
@@ -101,12 +101,17 @@ class AxiosHeaders {
     } else if(utils.isString(header) && (header = header.trim()) && !isValidHeaderName(header)) {
       setHeaders(parseHeaders(header), valueOrRewrite);
     } else if (utils.isObject(header) && utils.isIterable(header)) {
+      let obj = {}, dest, key;
       for (const entry of header) {
         if (!utils.isArray(entry)) {
           throw TypeError('Object iterator must return a key-value pair');
         }
-        setHeader(entry[1], entry[0], rewrite);
+
+        obj[key = entry[0]] = (dest = obj[key]) ?
+          (utils.isArray(dest) ? [...dest, entry[1]] : [dest, entry[1]]) : entry[1];
       }
+
+      setHeaders(obj, valueOrRewrite)
     } else {
       header != null && setHeader(valueOrRewrite, header, rewrite);
     }
diff --git a/test/helpers/retry.js b/test/helpers/retry.js
new file mode 100644
index 0000000..a4ccfbd
--- /dev/null
+++ b/test/helpers/retry.js
@@ -0,0 +1,18 @@
+
+export const retryNetwork = async (fn, retries = 3, delay = 1000) => {
+  let attempt = 0, sleep;
+
+  do {
+    try {
+      return await fn()
+    } catch (err) {
+      if (err.code === 'ERR_NETWORK' && attempt++ < retries) {
+        sleep = attempt * attempt * delay;
+        console.warn(`[ERR_NETWORK]: Attempt ${attempt}/${retries}${err.config ? ' [' + err.config.url + ']' : ''} sleep [${sleep}ms]`);
+        await new Promise(resolve => setTimeout(resolve, sleep));
+      } else {
+        throw err;
+      }
+    }
+  } while (true);
+}
diff --git a/test/specs/formdata.spec.js b/test/specs/formdata.spec.js
index 5c8cca7..b43fdef 100644
--- a/test/specs/formdata.spec.js
+++ b/test/specs/formdata.spec.js
@@ -1,13 +1,16 @@
+import {retryNetwork} from "../helpers/retry.js";
 
 describe('FormData', function() {
-  it('should allow FormData posting', function () {
-    return axios.postForm('http://httpbin.org/post', {
-      a: 'foo',
-      b: 'bar'
-    }).then(({data}) => {
-      expect(data.form).toEqual({
+  it('should allow FormData posting', async () => {
+    await retryNetwork(() => {
+      return axios.postForm('http://httpbin.org/post', {
         a: 'foo',
         b: 'bar'
+      }).then(({data}) => {
+        expect(data.form).toEqual({
+          a: 'foo',
+          b: 'bar'
+        });
       });
     });
   });
diff --git a/test/unit/core/AxiosHeaders.js b/test/unit/core/AxiosHeaders.js
index 0c5258c..2551fd6 100644
--- a/test/unit/core/AxiosHeaders.js
+++ b/test/unit/core/AxiosHeaders.js
@@ -1,6 +1,7 @@
 import AxiosHeaders from '../../../lib/core/AxiosHeaders.js';
 import assert from 'assert';
 
+const [nodeMajorVersion] = process.versions.node.split('.').map(v => parseInt(v, 10));
 
 describe('AxiosHeaders', function () {
   it('should support headers argument', function () {
@@ -82,6 +83,27 @@ describe('AxiosHeaders', function () {
 
       assert.strictEqual(headers.get('x'), '123');
     });
+
+    it('should support setting multiple header values from an iterable source', function () {
+      if (nodeMajorVersion < 18) {
+        this.skip();
+        return;
+      }
+
+      const headers = new AxiosHeaders();
+
+      const nativeHeaders = new Headers();
+
+      nativeHeaders.append('set-cookie', 'foo');
+      nativeHeaders.append('set-cookie', 'bar');
+      nativeHeaders.append('set-cookie', 'baz');
+      nativeHeaders.append('y', 'qux');
+
+      headers.set(nativeHeaders);
+
+      assert.deepStrictEqual(headers.get('set-cookie'), ['foo', 'bar', 'baz']);
+      assert.strictEqual(headers.get('y'), 'qux');
+    });
   });
 
   it('should support uppercase name mapping for names overlapped by class methods', () => {