From 293ad7edebb3ae30369288bd6416ca0d78474727 Mon Sep 17 00:00:00 2001
From: Amirhf <amirhacking85@gmail.com>
Date: Mon, 22 Jun 2026 14:39:26 +0330
Subject: [PATCH] fix(context): Copy() copies Errors and Accepted fields
 (#4695)

* Previously, Copy() only copied Keys and Params, leaving Errors and
Accepted as nil even when set on the original context. Goroutines
receiving a copied context could not observe errors attached before
the copy, and content-negotiation state set by middleware was silently
lost.

* Replace assert.Equal(t, len(c.Errors), len(cp.Errors)) with assert.Len(t, cp.Errors, 2) to satisfy the testifylint linter rule

---------

Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>
---
 context.go      | 10 ++++++++++
 context_test.go | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/context.go b/context.go
index a2e28e5b..640e20b2 100644
--- a/context.go
+++ b/context.go
@@ -141,6 +141,16 @@ func (c *Context) Copy() *Context {
 	cp.Params = make([]Param, len(cParams))
 	copy(cp.Params, cParams)
 
+	if c.Errors != nil {
+		cp.Errors = make(errorMsgs, len(c.Errors))
+		copy(cp.Errors, c.Errors)
+	}
+
+	if c.Accepted != nil {
+		cp.Accepted = make([]string, len(c.Accepted))
+		copy(cp.Accepted, c.Accepted)
+	}
+
 	return &cp
 }
 
diff --git a/context_test.go b/context_test.go
index 364a92ae..2dfdd392 100644
--- a/context_test.go
+++ b/context_test.go
@@ -689,6 +689,50 @@ func TestContextCopy(t *testing.T) {
 	assert.Equal(t, cp.fullPath, c.fullPath)
 }
 
+func TestContextCopyCopiesErrors(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest(http.MethodGet, "/", nil)
+	_ = c.Error(errors.New("first error"))
+	_ = c.Error(errors.New("second error"))
+
+	cp := c.Copy()
+
+	// copied context has the same errors
+	assert.Len(t, cp.Errors, 2)
+	assert.Equal(t, c.Errors[0].Error(), cp.Errors[0].Error())
+	assert.Equal(t, c.Errors[1].Error(), cp.Errors[1].Error())
+
+	// mutations on the copy do not affect the original
+	_ = cp.Error(errors.New("third error"))
+	assert.Len(t, c.Errors, 2)
+	assert.Len(t, cp.Errors, 3)
+}
+
+func TestContextCopyCopiesAccepted(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest(http.MethodGet, "/", nil)
+	c.SetAccepted("application/json", "text/html")
+
+	cp := c.Copy()
+
+	assert.Equal(t, c.Accepted, cp.Accepted)
+
+	// mutations on the copy do not affect the original
+	cp.SetAccepted("text/plain")
+	assert.Equal(t, []string{"application/json", "text/html"}, c.Accepted)
+	assert.Equal(t, []string{"text/plain"}, cp.Accepted)
+}
+
+func TestContextCopyNilErrorsAndAccepted(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest(http.MethodGet, "/", nil)
+
+	cp := c.Copy()
+
+	assert.Nil(t, cp.Errors)
+	assert.Nil(t, cp.Accepted)
+}
+
 func TestContextHandlerName(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	c.handlers = HandlersChain{func(c *Context) {}, handlerNameTest}