go/printer, gofmt: fix formatting of expression lists (missing blank)

This appears to have been a long-standing formatting bug.
The test cases has misformatted golden files.

Applied gofmt -w src misc .

Fixes #1839.

R=iant
CC=golang-dev
https://golang.org/cl/4515113

misc/dashboard/builder/http.go

@@ -73,7 +73,7 @@ func dashStatus(meth, cmd string, args param) os.Error {
 
 // todo returns the next hash to build.
 func (b *Builder) todo() (rev string, err os.Error) {
-	var resp []struct{
+	var resp []struct {
 		Hash string
 	}
 	if err = dash("GET", "todo", &resp, param{"builder": b.name}); err != nil {

misc/dashboard/builder/main.go

@@ -434,8 +434,8 @@ func commitPoll(key string) {
 
 	data, _, err := runLog(nil, "", goroot, "hg", "log",
 		"--encoding=utf-8",
-		"--limit=" + strconv.Itoa(N),
-		"--template=" + xmlLogTemplate,
+		"--limit="+strconv.Itoa(N),
+		"--template="+xmlLogTemplate,
 	)
 	if err != nil {
 		log.Printf("hg log: %v", err)
@@ -445,7 +445,7 @@ func commitPoll(key string) {
 	var logStruct struct {
 		Log []HgLog
 	}
-	err = xml.Unmarshal(strings.NewReader("<top>" + data + "</top>"), &logStruct)
+	err = xml.Unmarshal(strings.NewReader("<top>"+data+"</top>"), &logStruct)
 	if err != nil {
 		log.Printf("unmarshal hg log: %v", err)
 		return

src/pkg/go/printer/nodes.go

@@ -215,12 +215,13 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 		}
 
 		if i > 0 {
-			if mode&commaSep != 0 {
+			switch {
+			case mode&commaSep != 0:
 				p.print(token.COMMA)
-			}
-			if mode&periodSep != 0 {
+			case mode&periodSep != 0:
 				p.print(token.PERIOD)
 			}
+			needsBlank := mode&periodSep == 0 // period-separated list elements don't need a blank
 			if prevLine < line && prevLine > 0 && line > 0 {
 				// lines are broken using newlines so comments remain aligned
 				// unless forceFF is set or there are multiple expressions on
@@ -229,11 +230,12 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 					ws = ignore
 					*multiLine = true
 					prevBreak = i
+					needsBlank = false // we got a line break instead
 				}
-			} else if mode&periodSep == 0 {
+			}
+			if needsBlank {
 				p.print(blank)
 			}
-			// period-separated list elements don't need a blank
 		}
 
 		if isPair && size > 0 && len(list) > 1 {

src/pkg/go/printer/testdata/expressions.golden

@@ -644,7 +644,7 @@ func _() {
 func f() {
 	// os.Open parameters should remain on two lines
 	if writer, err = os.Open(outfile, s.O_WRONLY|os.O_CREATE|
-		os.O_TRUNC,0666); err != nil {
+		os.O_TRUNC, 0666); err != nil {
 		log.Fatal(err)
 	}
 }

src/pkg/go/printer/testdata/expressions.raw

@@ -644,7 +644,7 @@ func _() {
 func f() {
 	// os.Open parameters should remain on two lines
 	if writer, err = os.Open(outfile, s.O_WRONLY|os.O_CREATE|
-		os.O_TRUNC,0666); err != nil {
+		os.O_TRUNC, 0666); err != nil {
 		log.Fatal(err)
 	}
 }

src/pkg/http/serve_test.go

@@ -624,7 +624,7 @@ func TestServerConsumesRequestBody(t *testing.T) {
 		"POST / HTTP/1.1\r\n"+
 			"Host: test\r\n"+
 			"Content-Length: %d\r\n"+
-			"\r\n",len(body))))
+			"\r\n", len(body))))
 	conn.readBuf.Write([]byte(body))
 
 	done := make(chan bool)

src/pkg/mime/multipart/multipart_test.go

@@ -315,7 +315,7 @@ foo: bar
 
 
 --MyBoundary--
-`,"\n", "\r\n", -1)
+`, "\n", "\r\n", -1)
 	r := NewReader(strings.NewReader(testBody), "MyBoundary")
 	part, err := r.NextPart()
 	if err != nil {

src/pkg/os/user/user_test.go

@@ -56,6 +56,6 @@ func TestLookup(t *testing.T) {
 	if !reflect.DeepEqual(u, un) {
 		t.Errorf("Lookup by userid vs. name didn't match\n"+
 			"LookupId(%d): %#v\n"+
-			"Lookup(%q): %#v\n",uid, u, u.Username, un)
+			"Lookup(%q): %#v\n", uid, u, u.Username, un)
 	}
 }