fmt.Print: fix bug in placement of spaces introduced when ...T went in.

Fixes #976.

R=rsc, chris tighe, r
CC=golang-dev
https://golang.org/cl/1697057

diff --git a/src/pkg/fmt/fmt_test.go b/src/pkg/fmt/fmt_test.go
index 7e59d4073e3284ba1bcd6f4ae24f5c9b0e44c39f..7a4ad7d00bb4a15623bcf648d9aee27acfd2941e 100644 (file)
--- a/src/pkg/fmt/fmt_test.go
+++ b/src/pkg/fmt/fmt_test.go
@@ -526,3 +526,23 @@ func TestEmptyMap(t *testing.T) {
                t.Errorf("empty map printed as %q not %q", s, emptyMapStr)
        }
 }
+
+// Check that Sprint (and hence Print, Fprint) puts spaces in the right places,
+// that is, between arg pairs in which neither is a string.
+func TestBlank(t *testing.T) {
+       got := Sprint("<", 1, ">:", 1, 2, 3, "!")
+       expect := "<1>:1 2 3!"
+       if got != expect {
+               t.Errorf("got %q expected %q", got, expect)
+       }
+}
+
+// Check that Sprintln (and hence Println, Fprintln) puts spaces in the right places,
+// that is, between all arg pairs.
+func TestBlankln(t *testing.T) {
+       got := Sprintln("<", 1, ">:", 1, 2, 3, "!")
+       expect := "< 1 >: 1 2 3 !\n"
+       if got != expect {
+               t.Errorf("got %q expected %q", got, expect)
+       }
+}

diff --git a/src/pkg/fmt/print.go b/src/pkg/fmt/print.go
index 9ae7c39b4803b515d5764af2441364301ca2207f..d1ceb7c35fb2b470287e0571c7cb5f436acc37a2 100644 (file)
--- a/src/pkg/fmt/print.go
+++ b/src/pkg/fmt/print.go
@@ -492,7 +492,7 @@ var (
        uintptrBits = reflect.Typeof(uintptr(0)).Bits()
 )
 
-func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth int) (was_string bool) {
+func (p *pp) printField(field interface{}, verb int, plus, goSyntax bool, depth int) (wasString bool) {
        if field != nil {
                switch {
                default:
@@ -850,18 +850,18 @@ func (p *pp) doPrintf(format string, a []interface{}) {
 }
 
 func (p *pp) doPrint(a []interface{}, addspace, addnewline bool) {
-       prev_string := false
+       prevString := false
        for fieldnum := 0; fieldnum < len(a); fieldnum++ {
                p.fmt.clearflags()
                // always add spaces if we're doing println
                field := a[fieldnum]
                if fieldnum > 0 {
-                       _, is_string := field.(*reflect.StringValue)
-                       if addspace || !is_string && !prev_string {
+                       isString := field != nil && reflect.Typeof(field).Kind() == reflect.String
+                       if addspace || !isString && !prevString {
                                p.buf.WriteByte(' ')
                        }
                }
-               prev_string = p.printField(field, 'v', false, false, 0)
+               prevString = p.printField(field, 'v', false, false, 0)
        }
        if addnewline {
                p.buf.WriteByte('\n')