handle nils safely in Printf.
add some tests for erroneous formats.
R=rsc
CC=golang-dev
https://golang.org/cl/201058
diff --git a/src/pkg/fmt/fmt_test.go b/src/pkg/fmt/fmt_test.go
index ecceeb0..9fdf0dd 100644
--- a/src/pkg/fmt/fmt_test.go
+++ b/src/pkg/fmt/fmt_test.go
@@ -229,6 +229,11 @@
fmtTest{"%#v", make(chan int), "(chan int)(PTR)"},
fmtTest{"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
fmtTest{"%#v", 1000000000, "1000000000"},
+
+ // erroneous things
+ fmtTest{"%d", "hello", "%d(string=hello)"},
+ fmtTest{"no args", "hello", "no args?(extra string=hello)"},
+ fmtTest{"%s", nil, "%s(<nil>)"},
}
func TestSprintf(t *testing.T) {
diff --git a/src/pkg/fmt/print.go b/src/pkg/fmt/print.go
index de64179..e4840b9 100644
--- a/src/pkg/fmt/print.go
+++ b/src/pkg/fmt/print.go
@@ -378,6 +378,9 @@
}
func getString(a interface{}) (val string, ok bool) {
+ if a == nil {
+ return "<nil>", ok
+ }
// Is it a regular string or []byte type?
switch s := a.(type) {
case string:
@@ -941,8 +944,10 @@
p.buf.WriteByte('%')
p.add(c)
p.buf.WriteByte('(')
- p.buf.WriteString(reflect.Typeof(field).String())
- p.buf.WriteByte('=')
+ if field != nil {
+ p.buf.WriteString(reflect.Typeof(field).String())
+ p.buf.WriteByte('=')
+ }
p.printField(field, false, false, 0)
p.buf.WriteByte(')')
}
