From 2e2458816edbc4bbebbae2cacb54e323b90bb348 Mon Sep 17 00:00:00 2001
From: Sebastian Beltran <bjohansebas@gmail.com>
Date: Thu, 15 Jan 2026 17:10:53 -0500
Subject: [PATCH 1/4] fix: improve content-type handling in res.send method

---
 lib/response.js | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/lib/response.js b/lib/response.js
index 7a2f0ecce56..152ee1e075c 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -134,7 +134,13 @@ res.send = function send(body) {
   switch (typeof chunk) {
     // string defaulting to html
     case 'string':
-      if (!this.get('Content-Type')) {
+      encoding = 'utf8';
+      type = this.get('Content-Type');
+
+      // set content-type with charset in a single operation
+      if (type) {
+        this.set('Content-Type', setCharset(type, 'utf-8'));
+      } else {
         this.type('html');
       }
       break;
@@ -153,17 +159,6 @@ res.send = function send(body) {
       break;
   }
 
-  // write strings in utf-8
-  if (typeof chunk === 'string') {
-    encoding = 'utf8';
-    type = this.get('Content-Type');
-
-    // reflect this in content-type
-    if (typeof type === 'string') {
-      this.set('Content-Type', setCharset(type, 'utf-8'));
-    }
-  }
-
   // determine if ETag should be generated
   var etagFn = app.get('etag fn')
   var generateETag = !this.get('ETag') && typeof etagFn === 'function'

From 51caad20674d049a63e9608e9782f77e379959d2 Mon Sep 17 00:00:00 2001
From: Sebastian Beltran <bjohansebas@gmail.com>
Date: Thu, 15 Jan 2026 21:35:42 -0500
Subject: [PATCH 2/4] fix: ensure content-type is a string before setting
 charset in res.send

---
 lib/response.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/response.js b/lib/response.js
index 152ee1e075c..8122c29e8f8 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -138,7 +138,7 @@ res.send = function send(body) {
       type = this.get('Content-Type');
 
       // set content-type with charset in a single operation
-      if (type) {
+      if (typeof type === "string") {
         this.set('Content-Type', setCharset(type, 'utf-8'));
       } else {
         this.type('html');

From 1f683d5f1e283ec2e6bfa25c75cd827a7583b723 Mon Sep 17 00:00:00 2001
From: Sebastian Beltran <bjohansebas@gmail.com>
Date: Fri, 16 Jan 2026 15:46:26 -0500
Subject: [PATCH 3/4] fix: refactor content-type handling in res.send to use
 const and improve clarity

---
 lib/response.js | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/lib/response.js b/lib/response.js
index 8122c29e8f8..39e59116bd5 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -126,7 +126,6 @@ res.send = function send(body) {
   var chunk = body;
   var encoding;
   var req = this.req;
-  var type;
 
   // settings
   var app = this.app;
@@ -135,11 +134,10 @@ res.send = function send(body) {
     // string defaulting to html
     case 'string':
       encoding = 'utf8';
-      type = this.get('Content-Type');
+      const type = this.get('Content-Type');
 
-      // set content-type with charset in a single operation
-      if (typeof type === "string") {
-        this.set('Content-Type', setCharset(type, 'utf-8'));
+      if (typeof type === 'string') {
+        this.set('Content-Type', setCharset(type, encoding));
       } else {
         this.type('html');
       }

From bf678ff1f4568cae16f24035a9e8d9c4fab64d38 Mon Sep 17 00:00:00 2001
From: Sebastian Beltran <bjohansebas@gmail.com>
Date: Fri, 16 Jan 2026 15:59:04 -0500
Subject: [PATCH 4/4] Apply suggestion from @bjohansebas

---
 lib/response.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/response.js b/lib/response.js
index 39e59116bd5..1a4d2deff26 100644
--- a/lib/response.js
+++ b/lib/response.js
@@ -137,7 +137,7 @@ res.send = function send(body) {
       const type = this.get('Content-Type');
 
       if (typeof type === 'string') {
-        this.set('Content-Type', setCharset(type, encoding));
+        this.set('Content-Type', setCharset(type, 'utf-8'));
       } else {
         this.type('html');
       }