src/pkg/go/printer/printer.go               | 31 +++++++++++++++++++++----------
 src/pkg/go/printer/testdata/comments.golden | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/pkg/go/printer/testdata/comments.input  | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++

diff --git a/src/pkg/go/printer/printer.go b/src/pkg/go/printer/printer.go
index 304ba0b0ac284991799105739e501391089d288d..90f3e20161a0ecf263d2c06f7514738a4fc0a701 100644
--- a/src/pkg/go/printer/printer.go
+++ b/src/pkg/go/printer/printer.go
@@ -429,6 +429,7 @@ func stripCommonPrefix(lines [][]byte) {
 	if len(lines) < 2 {
 		return // at most one line - nothing to do
 	}
+	// len(lines) >= 2
 
 	// The heuristic in this function tries to handle a few
 	// common patterns of /*-style comments: Comments where
@@ -441,18 +442,28 @@
 	// Compute maximum common white prefix of all but the first,
 	// last, and blank lines, and replace blank lines with empty
 	// lines (the first line starts with /* and has no prefix).
+	// In case of two-line comments, consider the last line for
+	// the prefix computation since otherwise the prefix would
+	// be empty.
+	//
+	// Note that the first and last line are never empty (they
+	// contain the opening /* and closing */ respectively) and
+	// thus they can be ignored by the blank line check.
 	var prefix []byte
-	for i, line := range lines {
-		switch {
-		case i == 0 || i == len(lines)-1:
-			// ignore
-		case isBlank(line):
-			lines[i] = nil
-		case prefix == nil:
-			prefix = commonPrefix(line, line)
-		default:
-			prefix = commonPrefix(prefix, line)
+	if len(lines) > 2 {
+		for i, line := range lines[1 : len(lines)-1] {
+			switch {
+			case isBlank(line):
+				lines[i+1] = nil
+			case prefix == nil:
+				prefix = commonPrefix(line, line)
+			default:
+				prefix = commonPrefix(prefix, line)
+			}
 		}
+	} else { // len(lines) == 2
+		line := lines[1]
+		prefix = commonPrefix(line, line)
 	}
 
 	/*
diff --git a/src/pkg/go/printer/testdata/comments.golden b/src/pkg/go/printer/testdata/comments.golden
index 741500c621bc4e8a486019051bab5adf8f4b7fa2..18a407478ecb8363e669d4f806bc9e096d45627e 100644
--- a/src/pkg/go/printer/testdata/comments.golden
+++ b/src/pkg/go/printer/testdata/comments.golden
@@ -217,6 +217,80 @@ 		aligned		line
 		aligned line */
 }
 
+func _() {
+	/* freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/* freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/* freestanding comment
+	   aligned line */
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line */
+}
+
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line */
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line */
+}
 
 /*
  * line
@@ -231,6 +305,24 @@
 /*	and another line
  *	of
  *	stars */
+
+/* a line of
+ * stars */
+
+/*	and another line of
+ *	stars */
+
+/* a line of stars
+ */
+
+/*	and another line of
+ */
+
+/* a line of stars
+ */
+
+/*	and another line of
+ */
 
 /*
 aligned in middle
diff --git a/src/pkg/go/printer/testdata/comments.input b/src/pkg/go/printer/testdata/comments.input
index 700a4923069460b0ca73cd4454328e50caa8098f..8cba7e5a2cd4090bb132477e6ffcbb39011165e5 100644
--- a/src/pkg/go/printer/testdata/comments.input
+++ b/src/pkg/go/printer/testdata/comments.input
@@ -217,6 +217,80 @@ 		aligned		line
 		aligned line */
 }
 
+func _() {
+	/* freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/* freestanding comment
+	   aligned line
+	   */
+}
+
+func _() {
+	/* freestanding comment
+	   aligned line */
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line
+		*/
+}
+
+func _() {
+	/*	freestanding comment
+		aligned line */
+}
+
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line
+	*/
+}
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line
+	   */
+}
+
+func _() {
+	/*
+	   freestanding comment
+	   aligned line */
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line
+	*/
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line
+		*/
+}
+
+func _() {
+	/*
+		freestanding comment
+		aligned line */
+}
 
 /*
  * line
@@ -231,6 +305,24 @@
 /*	and another line
  *	of
  *	stars */
+
+/* a line of
+ * stars */
+
+/*	and another line of
+ *	stars */
+
+/* a line of stars
+*/
+
+/*	and another line of
+*/
+
+/* a line of stars
+ */
+
+/*	and another line of
+ */
 
 /*
 aligned in middle