From 65639e876cfcda0cb7986b2b97d6424c857ca62d Mon Sep 17 00:00:00 2001
From: OHZEKI Naoki <0h23k1.n40k1@gmail.com>
Date: Fri, 10 Oct 2025 21:42:55 +0900
Subject: [PATCH 1/3] refactor(recovery): rename var in
 CustomRecoveryWithWriter

---
 recovery.go | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/recovery.go b/recovery.go
index fdd463f3..06da69e8 100644
--- a/recovery.go
+++ b/recovery.go
@@ -54,38 +54,38 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 	}
 	return func(c *Context) {
 		defer func() {
-			if err := recover(); err != nil {
+			if rec := recover(); rec != nil {
 				// Check for a broken connection, as it is not really a
 				// condition that warrants a panic stack trace.
-				var brokenPipe bool
-				if ne, ok := err.(*net.OpError); ok {
+				var isBrokenPipeOrConnReset bool
+				if ne, ok := rec.(*net.OpError); ok {
 					var se *os.SyscallError
 					if errors.As(ne, &se) {
 						seStr := strings.ToLower(se.Error())
 						if strings.Contains(seStr, "broken pipe") ||
 							strings.Contains(seStr, "connection reset by peer") {
-							brokenPipe = true
+							isBrokenPipeOrConnReset = true
 						}
 					}
 				}
 				if logger != nil {
 					const stackSkip = 3
-					if brokenPipe {
-						logger.Printf("%s\n%s%s", err, secureRequestDump(c.Request), reset)
+					if isBrokenPipeOrConnReset {
+						logger.Printf("%s\n%s%s", rec, secureRequestDump(c.Request), reset)
 					} else if IsDebugging() {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s\n%s%s",
-							timeFormat(time.Now()), secureRequestDump(c.Request), err, stack(stackSkip), reset)
+							timeFormat(time.Now()), secureRequestDump(c.Request), rec, stack(stackSkip), reset)
 					} else {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s%s",
-							timeFormat(time.Now()), err, stack(stackSkip), reset)
+							timeFormat(time.Now()), rec, stack(stackSkip), reset)
 					}
 				}
-				if brokenPipe {
+				if isBrokenPipeOrConnReset {
 					// If the connection is dead, we can't write a status to it.
-					c.Error(err.(error)) //nolint: errcheck
+					c.Error(rec.(error)) //nolint: errcheck
 					c.Abort()
 				} else {
-					handle(c, err)
+					handle(c, rec)
 				}
 			}
 		}()

From 6cfc3cd0fc1234755e2def6df0345fd8d4bba8a4 Mon Sep 17 00:00:00 2001
From: OHZEKI Naoki <0h23k1.n40k1@gmail.com>
Date: Fri, 10 Oct 2025 21:56:35 +0900
Subject: [PATCH 2/3] refactor(recovery): smart error comparison

---
 recovery.go | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/recovery.go b/recovery.go
index 06da69e8..85cb0411 100644
--- a/recovery.go
+++ b/recovery.go
@@ -10,12 +10,12 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"net"
 	"net/http"
 	"net/http/httputil"
 	"os"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/gin-gonic/gin/internal/bytesconv"
@@ -58,15 +58,9 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 				// Check for a broken connection, as it is not really a
 				// condition that warrants a panic stack trace.
 				var isBrokenPipeOrConnReset bool
-				if ne, ok := rec.(*net.OpError); ok {
-					var se *os.SyscallError
-					if errors.As(ne, &se) {
-						seStr := strings.ToLower(se.Error())
-						if strings.Contains(seStr, "broken pipe") ||
-							strings.Contains(seStr, "connection reset by peer") {
-							isBrokenPipeOrConnReset = true
-						}
-					}
+				err, ok := rec.(error)
+				if ok {
+					isBrokenPipeOrConnReset = errors.Is(err, syscall.EPIPE) || errors.Is(err, syscall.ECONNRESET)
 				}
 				if logger != nil {
 					const stackSkip = 3
@@ -82,7 +76,7 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 				}
 				if isBrokenPipeOrConnReset {
 					// If the connection is dead, we can't write a status to it.
-					c.Error(rec.(error)) //nolint: errcheck
+					c.Error(err) //nolint: errcheck
 					c.Abort()
 				} else {
 					handle(c, rec)

From 75b09bd1895c6047cc71ba99b45d738872bd4427 Mon Sep 17 00:00:00 2001
From: OHZEKI Naoki <0h23k1.n40k1@gmail.com>
Date: Wed, 28 May 2025 20:27:54 +0900
Subject: [PATCH 3/3] test(recovery): Directly reference the syscall error
 string

---
 recovery_test.go | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/recovery_test.go b/recovery_test.go
index 8a9e3475..5ce6cba8 100644
--- a/recovery_test.go
+++ b/recovery_test.go
@@ -113,13 +113,13 @@ func TestFunction(t *testing.T) {
 func TestPanicWithBrokenPipe(t *testing.T) {
 	const expectCode = 204
 
-	expectMsgs := map[syscall.Errno]string{
-		syscall.EPIPE:      "broken pipe",
-		syscall.ECONNRESET: "connection reset by peer",
+	expectErrnos := []syscall.Errno{
+		syscall.EPIPE,
+		syscall.ECONNRESET,
 	}
 
-	for errno, expectMsg := range expectMsgs {
-		t.Run(expectMsg, func(t *testing.T) {
+	for _, errno := range expectErrnos {
+		t.Run("Recovery from "+errno.Error(), func(t *testing.T) {
 			var buf strings.Builder
 
 			router := New()
@@ -137,7 +137,8 @@ func TestPanicWithBrokenPipe(t *testing.T) {
 			w := PerformRequest(router, http.MethodGet, "/recovery")
 			// TEST
 			assert.Equal(t, expectCode, w.Code)
-			assert.Contains(t, strings.ToLower(buf.String()), expectMsg)
+			assert.Contains(t, strings.ToLower(buf.String()), errno.Error())
+			assert.NotContains(t, strings.ToLower(buf.String()), "[Recovery]")
 		})
 	}
 }