cmd/doc: add a line gap after a method with no comment

Fixes #30492

Change-Id: Iec658bdf8bfac21e1bcc3eed900722cc535ec00a
Reviewed-on: https://go-review.googlesource.com/c/go/+/166178
Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

src/cmd/doc/doc_test.go

@@ -496,6 +496,7 @@ var tests = []test{
 			`func ReturnExported\(\) ExportedType`,
 			`func \(ExportedType\) ExportedMethod\(a int\) bool`,
 			`Comment about exported method.`,
+			`func \(ExportedType\) Uncommented\(a int\) bool\n\n`, // Ensure line gap after method with no comment
 		},
 		[]string{
 			`unexportedType`,

src/cmd/doc/pkg.go

@@ -808,6 +808,9 @@ func (pkg *Package) typeDoc(typ *doc.Type) {
 		for _, fun := range funcs {
 			if isExported(fun.Name) {
 				pkg.emit(fun.Doc, fun.Decl)
+				if fun.Doc == "" {
+					pkg.newlines(2)
+				}
 			}
 		}
 	} else {

src/cmd/doc/testdata/pkg.go

@@ -80,6 +80,10 @@ func (ExportedType) ExportedMethod(a int) bool {
 	return true != true
 }
 
+func (ExportedType) Uncommented(a int) bool {
+	return true != true
+}
+
 // Comment about unexported method.
 func (ExportedType) unexportedMethod(a int) bool {
 	return true