diff --git a/src/encoding/json/decode_test.go b/src/encoding/json/decode_test.go index 8dcb08cbd2..31ab61c733 100644 --- a/src/encoding/json/decode_test.go +++ b/src/encoding/json/decode_test.go @@ -2345,6 +2345,41 @@ func TestUnmarshalEmbeddedUnexported(t *testing.T) { } } +func TestUnmarshalErrorAfterMultipleJSON(t *testing.T) { + tests := []struct { + in string + err error + }{{ + in: `1 false null :`, + err: &SyntaxError{"invalid character ':' looking for beginning of value", 14}, + }, { + in: `1 [] [,]`, + err: &SyntaxError{"invalid character ',' looking for beginning of value", 7}, + }, { + in: `1 [] [true:]`, + err: &SyntaxError{"invalid character ':' after array element", 11}, + }, { + in: `1 {} {"x"=}`, + err: &SyntaxError{"invalid character '=' after object key", 14}, + }, { + in: `falsetruenul#`, + err: &SyntaxError{"invalid character '#' in literal null (expecting 'l')", 13}, + }} + for i, tt := range tests { + dec := NewDecoder(strings.NewReader(tt.in)) + var err error + for { + var v interface{} + if err = dec.Decode(&v); err != nil { + break + } + } + if !reflect.DeepEqual(err, tt.err) { + t.Errorf("#%d: got %#v, want %#v", i, err, tt.err) + } + } +} + type unmarshalPanic struct{} func (unmarshalPanic) UnmarshalJSON([]byte) error { panic(0xdead) } diff --git a/src/encoding/json/stream.go b/src/encoding/json/stream.go index e29127499b..3d30322ce2 100644 --- a/src/encoding/json/stream.go +++ b/src/encoding/json/stream.go @@ -102,6 +102,10 @@ Input: dec.scan.bytes++ switch dec.scan.step(&dec.scan, c) { case scanEnd: + // scanEnd is delayed one byte so we decrement + // the scanner bytes count by 1 to ensure that + // this value is correct in the next call of Decode. + dec.scan.bytes-- break Input case scanEndObject, scanEndArray: // scanEnd is delayed one byte.