From: Marcus Weiner <marcus.weiner@gmail.com>
Date: Wed, 9 Nov 2022 10:37:28 +0000 (+0000)
Subject: net/http: build error chains in transport that can be unwrapped
X-Git-Tag: go1.20rc1~323
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=531ba0c8aae9efe25e33bf0bfa40f4941d8c5ab8;p=gostls13.git

net/http: build error chains in transport that can be unwrapped

In some places of the HTTP transport errors were constructed that
wrapped other errors without providing the ability to call
`errors.Unwrap` on them to get the underlying error.
These places have been fixed to use `%w` when using `fmt.Errorf`
or to implement `Unwrap() error`.

Fixes #56435

Change-Id: Ieed3359281574485c8d0b18298e25e5f1e14555c
GitHub-Last-Rev: 504efbc507a50bd2cf63001511733e232927089f
GitHub-Pull-Request: golang/go#56451
Reviewed-on: https://go-review.googlesource.com/c/go/+/445775
Reviewed-by: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Damien Neil <dneil@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
---

diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 2a508ec41b..184cf27518 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -2057,7 +2057,7 @@ func (pc *persistConn) mapRoundTripError(req *transportRequest, startBytesWritte
 		if pc.nwrite == startBytesWritten {
 			return nothingWrittenError{err}
 		}
-		return fmt.Errorf("net/http: HTTP/1.x transport connection broken: %v", err)
+		return fmt.Errorf("net/http: HTTP/1.x transport connection broken: %w", err)
 	}
 	return err
 }
@@ -2264,7 +2264,7 @@ func (pc *persistConn) readLoopPeekFailLocked(peekErr error) {
 		// common case.
 		pc.closeLocked(errServerClosedIdle)
 	} else {
-		pc.closeLocked(fmt.Errorf("readLoopPeekFailLocked: %v", peekErr))
+		pc.closeLocked(fmt.Errorf("readLoopPeekFailLocked: %w", peekErr))
 	}
 }
 
@@ -2398,6 +2398,10 @@ type nothingWrittenError struct {
 	error
 }
 
+func (nwe nothingWrittenError) Unwrap() error {
+	return nwe.error
+}
+
 func (pc *persistConn) writeLoop() {
 	defer close(pc.writeLoopDone)
 	for {
@@ -2635,7 +2639,7 @@ func (pc *persistConn) roundTrip(req *transportRequest) (resp *Response, err err
 				req.logf("writeErrCh resv: %T/%#v", err, err)
 			}
 			if err != nil {
-				pc.close(fmt.Errorf("write error: %v", err))
+				pc.close(fmt.Errorf("write error: %w", err))
 				return nil, pc.mapRoundTripError(req, startBytesWritten, err)
 			}
 			if d := pc.t.ResponseHeaderTimeout; d > 0 {