From d2fd503f687ca686cb8fbee0b29e64ba529038fe Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Wed, 5 May 2021 21:13:24 -0400 Subject: [PATCH] text/template: fix type bug in eq {{eq .x 0}} where .x is a nil interface{} should be false, not a type error. Similarly, {{eq .x .x}} should succeed, not panic in reflect. Fixes #45982. Change-Id: I90aba82bb2f1a9e162bde1290c94f5028f56f412 Reviewed-on: https://go-review.googlesource.com/c/go/+/317470 Trust: Russ Cox Run-TryBot: Russ Cox TryBot-Result: Go Bot Reviewed-by: Rob Pike --- src/text/template/exec_test.go | 19 +++++++++++-------- src/text/template/funcs.go | 6 ++++-- 2 files changed, 15 insertions(+), 10 deletions(-) diff --git a/src/text/template/exec_test.go b/src/text/template/exec_test.go index e73fce4fa8..ef521645a7 100644 --- a/src/text/template/exec_test.go +++ b/src/text/template/exec_test.go @@ -1201,8 +1201,11 @@ var cmpTests = []cmpTest{ {"eq .Ptr .NilPtr", "false", true}, {"eq .NilPtr .NilPtr", "true", true}, {"eq .Iface1 .Iface1", "true", true}, - {"eq .Iface1 .Iface2", "false", true}, - {"eq .Iface2 .Iface2", "true", true}, + {"eq .Iface1 .NilIface", "false", true}, + {"eq .NilIface .NilIface", "true", true}, + {"eq .NilIface .Iface1", "false", true}, + {"eq .NilIface 0", "false", true}, + {"eq 0 .NilIface", "false", true}, // Errors {"eq `xy` 1", "", false}, // Different types. {"eq 2 2.0", "", false}, // Different types. @@ -1217,12 +1220,12 @@ var cmpTests = []cmpTest{ func TestComparison(t *testing.T) { b := new(bytes.Buffer) var cmpStruct = struct { - Uthree, Ufour uint - NegOne, Three int - Ptr, NilPtr *int - Map map[int]int - V1, V2 V - Iface1, Iface2 fmt.Stringer + Uthree, Ufour uint + NegOne, Three int + Ptr, NilPtr *int + Map map[int]int + V1, V2 V + Iface1, NilIface fmt.Stringer }{ Uthree: 3, Ufour: 4, diff --git a/src/text/template/funcs.go b/src/text/template/funcs.go index 9dd332c068..fff833ed29 100644 --- a/src/text/template/funcs.go +++ b/src/text/template/funcs.go @@ -478,7 +478,9 @@ func eq(arg1 reflect.Value, arg2 ...reflect.Value) (bool, error) { case k1 == uintKind && k2 == intKind: truth = arg.Int() >= 0 && arg1.Uint() == uint64(arg.Int()) default: - return false, errBadComparison + if arg1 != zero && arg != zero { + return false, errBadComparison + } } } else { switch k1 { @@ -495,7 +497,7 @@ func eq(arg1 reflect.Value, arg2 ...reflect.Value) (bool, error) { case uintKind: truth = arg1.Uint() == arg.Uint() default: - if arg == zero { + if arg == zero || arg1 == zero { truth = arg1 == arg } else { if t2 := arg.Type(); !t2.Comparable() { -- 2.50.0