59191 example works when flag is 1

src/go/ast/ast.go

@@ -8,9 +8,12 @@ package ast
 
 import (
 	"go/token"
+	"internal/godebug"
 	"strings"
 )
 
+var exampledontreduce = godebug.New("exampledontreduce")
+
 // ----------------------------------------------------------------------------
 // Interfaces
 //
@@ -141,13 +144,17 @@ func (g *CommentGroup) Text() string {
 	// Remove leading blank lines; convert runs of
 	// interior blank lines to a single blank line.
 	n := 0
-	for _, line := range lines {
-		if line != "" || n > 0 && lines[n-1] != "" {
-			lines[n] = line
-			n++
+	if exampledontreduce.Value() != "1" {
+		for _, line := range lines {
+			if line != "" || n > 0 && lines[n-1] != "" {
+				lines[n] = line
+				n++
+			}
 		}
+		lines = lines[0:n]
+	} else {
+		n = len(lines)
 	}
-	lines = lines[0:n]
 
 	// Add final "" entry to get trailing newline from Join.
 	if n > 0 && lines[n-1] != "" {

src/go/doc/example_test.go

@@ -21,6 +21,7 @@ import (
 )
 
 func TestExamples(t *testing.T) {
+	t.Setenv("GODEBUG", "exampledontreduce=1")
 	dir := filepath.Join("testdata", "examples")
 	filenames, err := filepath.Glob(filepath.Join(dir, "*.go"))
 	if err != nil {

src/go/doc/testdata/examples/issue59191.go

@@ -0,0 +1,15 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package foo_test
+
+func Example() {
+	//Output:
+	//Single newline:
+	//
+	//Double newline:
+	//
+	//
+	//Final text
+}

src/go/doc/testdata/examples/issue59191.golden

@@ -0,0 +1,14 @@
+-- .Play --
+package main
+
+import ()
+
+func main() {
+}
+-- .Output --
+Single newline:
+
+Double newline:
+
+
+Final text