From f85c282a18bbe7197ba645fff58ba5e0065962ca Mon Sep 17 00:00:00 2001 From: Heschi Kreinick Date: Wed, 25 Jan 2023 12:48:54 -0500 Subject: [PATCH] internal/testpty: fix error handling When calling a c library function, you discover that an error has occurred, typically by looking at the return value of the function. Only after that can you use errno to figure out the cause of the error. Nothing about cgo changes that story -- you still have to look at the result before checking the error that represents errno. If not you can get false errors if the function happens to leak a non-zero errno. Fix testpty to check errors correctly. Change-Id: Idb95f8dd6a8ed63f653190c2e722e742cf50542b Reviewed-on: https://go-review.googlesource.com/c/go/+/463397 Run-TryBot: Heschi Kreinick Reviewed-by: Michael Pratt Auto-Submit: Heschi Kreinick TryBot-Result: Gopher Robot --- src/internal/testpty/pty_cgo.go | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/internal/testpty/pty_cgo.go b/src/internal/testpty/pty_cgo.go index 1db6a925af..442fbcf618 100644 --- a/src/internal/testpty/pty_cgo.go +++ b/src/internal/testpty/pty_cgo.go @@ -18,14 +18,14 @@ import "os" func open() (pty *os.File, processTTY string, err error) { m, err := C.posix_openpt(C.O_RDWR) - if err != nil { + if m < 0 { return nil, "", ptyError("posix_openpt", err) } - if _, err := C.grantpt(m); err != nil { + if res, err := C.grantpt(m); res < 0 { C.close(m) return nil, "", ptyError("grantpt", err) } - if _, err := C.unlockpt(m); err != nil { + if res, err := C.unlockpt(m); res < 0 { C.close(m) return nil, "", ptyError("unlockpt", err) } -- 2.48.1