Prevent superfluous response.WriteHeader (#15456) (#15476)

zeripath · web-flow · commit 00e55dd2235b · 2021-04-15T11:02:42.000+01:00
Backport #15456 This PR simply checks the status before writing the header. Signed-off-by: Andrew Thornton <art27@cantab.net>
diff --git a/modules/context/response.go b/modules/context/response.go
@@ -4,7 +4,9 @@
 
 package context
 
-import "net/http"
+import (
+	"net/http"
+)
 
 // ResponseWriter represents a response writer for HTTP
 type ResponseWriter interface {
@@ -60,8 +62,10 @@ func (r *Response) WriteHeader(statusCode int) {
 		}
 		r.beforeExecuted = true
 	}
-	r.status = statusCode
-	r.ResponseWriter.WriteHeader(statusCode)
+	if r.status == 0 {
+		r.status = statusCode
+		r.ResponseWriter.WriteHeader(statusCode)
+	}
 }
 
 // Flush flush cached data

Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,9 @@`
`4`	`4`
`5`	`5`	`package context`
`6`	`6`
`7`		`-import "net/http"`
	`7`	`+import (`
	`8`	`+ "net/http"`
	`9`	`+)`
`8`	`10`
`9`	`11`	`// ResponseWriter represents a response writer for HTTP`
`10`	`12`	`type ResponseWriter interface {`
`@@ -60,8 +62,10 @@ func (r *Response) WriteHeader(statusCode int) {`
`60`	`62`	`}`
`61`	`63`	`r.beforeExecuted = true`
`62`	`64`	`}`
`63`		`- r.status = statusCode`
`64`		`- r.ResponseWriter.WriteHeader(statusCode)`
	`65`	`+ if r.status == 0 {`
	`66`	`+ r.status = statusCode`
	`67`	`+ r.ResponseWriter.WriteHeader(statusCode)`
	`68`	`+ }`
`65`	`69`	`}`
`66`	`70`
`67`	`71`	`// Flush flush cached data`