go/printer, gofmt: fix multi-line logic

A node spans multiple lines if the line difference
between start and end point is > 0 (rather than > 1).
Fixes some odd cases introduced by CL 5706055;
pointed out by dsymonds.

Added corresponding test case. The other change
in the .golden file reverts to the status before
the CL mentioned above and is correct.

gofmt -w src misc changes godoc.go back to where
it was before the CL mentioned above.

Fixes #3304.

R=dsymonds, rsc
CC=golang-dev
https://golang.org/cl/5820044

src/pkg/go/printer/nodes.go

@@ -365,7 +365,7 @@ func (p *printer) setLineComment(text string) {
 }
 
 func (p *printer) isMultiLine(n ast.Node) bool {
-	return p.lineFor(n.End())-p.lineFor(n.Pos()) > 1
+	return p.lineFor(n.End())-p.lineFor(n.Pos()) > 0
 }
 
 func (p *printer) fieldList(fields *ast.FieldList, isStruct, isIncomplete bool) {

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

@@ -566,6 +566,17 @@ var (
 	a4, b4, c4	int	// this line should be indented
 )
 
+// Test case from issue 3304: multi-line declarations must end
+// a formatting section and not influence indentation of the
+// next line.
+var (
+	minRefreshTimeSec	= flag.Int64("min_refresh_time_sec", 604800,
+		"minimum time window between two refreshes for a given user.")
+	x	= flag.Int64("refresh_user_rollout_percent", 100,
+		"temporary flag to ramp up the refresh user rpc")
+	aVeryLongVariableName	= stats.GetVarInt("refresh-user-count")
+)
+
 func _() {
 	var privateKey2 = &Block{Type:	"RSA PRIVATE KEY",
 		Headers:	map[string]string{},

src/pkg/go/printer/testdata/declarations.input

@@ -577,6 +577,16 @@ c3, d3 int  // this line should be indented
 a4, b4, c4 int  // this line should be indented
 )
 
+// Test case from issue 3304: multi-line declarations must end
+// a formatting section and not influence indentation of the
+// next line.
+var (
+	minRefreshTimeSec = flag.Int64("min_refresh_time_sec", 604800,
+		"minimum time window between two refreshes for a given user.")
+	x = flag.Int64("refresh_user_rollout_percent", 100,
+		"temporary flag to ramp up the refresh user rpc")
+	aVeryLongVariableName = stats.GetVarInt("refresh-user-count")
+)
 
 func _() {
 	var privateKey2 = &Block{Type: "RSA PRIVATE KEY",