From 0bf1f02ed921ec2f78b27f133e7a688d3e8fa82e Mon Sep 17 00:00:00 2001 From: LE Manh Cuong Date: Sun, 5 May 2019 23:20:26 +0700 Subject: [PATCH] errors: fix Is panics if target is uncomparable Fixes #31841 Change-Id: I3f068686154fd2fa5755b0df47b4eaa5c9a19107 Reviewed-on: https://go-review.googlesource.com/c/go/+/175260 Reviewed-by: Damien Neil Reviewed-by: Brad Fitzpatrick Run-TryBot: Brad Fitzpatrick TryBot-Result: Gobot Gobot --- src/errors/wrap.go | 4 +++- src/errors/wrap_test.go | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/src/errors/wrap.go b/src/errors/wrap.go index 04ddf79ba3..69dd9464ec 100644 --- a/src/errors/wrap.go +++ b/src/errors/wrap.go @@ -51,8 +51,10 @@ func Is(err, target error) bool { if target == nil { return err == target } + + isComparable := target == nil || reflectlite.TypeOf(target).Comparable() for { - if err == target { + if isComparable && err == target { return true } if x, ok := err.(interface{ Is(error) bool }); ok && x.Is(target) { diff --git a/src/errors/wrap_test.go b/src/errors/wrap_test.go index 022f429c0c..f8e907cff7 100644 --- a/src/errors/wrap_test.go +++ b/src/errors/wrap_test.go @@ -47,6 +47,12 @@ func TestIs(t *testing.T) { {poser, errb, false}, {poser, erro, false}, {poser, errco, false}, + {errorUncomparable{}, errorUncomparable{}, true}, + {errorUncomparable{}, &errorUncomparable{}, false}, + {&errorUncomparable{}, errorUncomparable{}, true}, + {&errorUncomparable{}, &errorUncomparable{}, false}, + {errorUncomparable{}, err1, false}, + {&errorUncomparable{}, err1, false}, } for _, tc := range testCases { t.Run("", func(t *testing.T) { @@ -260,3 +266,16 @@ type printer struct { } func (p *printer) Print(args ...interface{}) { fmt.Fprint(&p.buf, args...) } + +type errorUncomparable struct { + f []string +} + +func (errorUncomparable) Error() string { + return "uncomparable error" +} + +func (errorUncomparable) Is(target error) bool { + _, ok := target.(errorUncomparable) + return ok +} -- 2.50.0