net/http: update bundled http2 for ErrAbortHandler support, document it more

Updates http2 to x/net/http2 git rev 0e2717d for:

   http2: conditionally log stacks from panics in Server Handlers like net/http
   https://golang.org/cl/33102

Fixes #17790

Change-Id: Idd3f0c65540398d41b412a33f1d80de3f7f31409
Reviewed-on: https://go-review.googlesource.com/33103
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>

diff --git a/src/net/http/clientserver_test.go b/src/net/http/clientserver_test.go
index 0d231b87b043837df851d0ae0c6623836b1b3111..286f8166093cee31d6c1f479a8db506859601672 100644 (file)
--- a/src/net/http/clientserver_test.go
+++ b/src/net/http/clientserver_test.go
@@ -1189,9 +1189,6 @@ func testInterruptWithPanic(t *testing.T, h2 bool, panicValue interface{}) {
                if gotLog == "" {
                        return
                }
-               if h2 {
-                       t.Skip("TODO: make http2.Server respect ErrAbortHandler")
-               }
                t.Fatalf("want no log output; got: %s", gotLog)
        }
        if gotLog == "" {

diff --git a/src/net/http/h2_bundle.go b/src/net/http/h2_bundle.go
index f606098796d9e8612baa25c9420b18a2ac669b79..20178dadf17963f4b236b4adac917d84e560324f 100644 (file)
--- a/src/net/http/h2_bundle.go
+++ b/src/net/http/h2_bundle.go
@@ -2184,6 +2184,10 @@ func http2configureServer18(h1 *Server, h2 *http2Server) error {
        return nil
 }
 
+func http2shouldLogPanic(panicValue interface{}) bool {
+       return panicValue != nil && panicValue != ErrAbortHandler
+}
+
 var http2DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1"
 
 type http2goroutineLock uint64
@@ -4534,15 +4538,17 @@ func (sc *http2serverConn) runHandler(rw *http2responseWriter, req *Request, han
                rw.rws.stream.cancelCtx()
                if didPanic {
                        e := recover()
-                       // Same as net/http:
-                       const size = 64 << 10
-                       buf := make([]byte, size)
-                       buf = buf[:runtime.Stack(buf, false)]
                        sc.writeFrameFromHandler(http2FrameWriteRequest{
                                write:  http2handlerPanicRST{rw.rws.stream.id},
                                stream: rw.rws.stream,
                        })
-                       sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
+
+                       if http2shouldLogPanic(e) {
+                               const size = 64 << 10
+                               buf := make([]byte, size)
+                               buf = buf[:runtime.Stack(buf, false)]
+                               sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
+                       }
                        return
                }
                rw.handlerDone()

diff --git a/src/net/http/server.go b/src/net/http/server.go
index 2bc71c7dd5796a84f1172442fbdaf58c6594c196..257d82f8aca0cec9bbcc162ce95d07f37ddec49b 100644 (file)
--- a/src/net/http/server.go
+++ b/src/net/http/server.go
@@ -75,7 +75,9 @@ var (
 // If ServeHTTP panics, the server (the caller of ServeHTTP) assumes
 // that the effect of the panic was isolated to the active request.
 // It recovers the panic, logs a stack trace to the server error log,
-// and hangs up the connection.
+// and hangs up the connection. To abort a handler so the client sees
+// an interrupted response but the server doesn't log an error, panic
+// with the value ErrAbortHandler.
 type Handler interface {
        ServeHTTP(ResponseWriter, *Request)
 }