From a47a45ec7741d677ea6582cdeee3419325ac9488 Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Tue, 15 Dec 2009 18:03:59 -0800
Subject: [PATCH] Fix for scanner bug (introduced with most recent change).

Fixes #433.

R=rsc
CC=golang-dev
https://golang.org/cl/179072
---
 src/pkg/go/scanner/scanner.go      | 8 ++++++--
 src/pkg/go/scanner/scanner_test.go | 2 ++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/pkg/go/scanner/scanner.go b/src/pkg/go/scanner/scanner.go
index fad3c0f754..4735cbd3b5 100644
--- a/src/pkg/go/scanner/scanner.go
+++ b/src/pkg/go/scanner/scanner.go
@@ -223,10 +223,10 @@ func (S *Scanner) findNewline(pos token.Position) bool {
 		}
 	}
 
-	// reset position
+	// reset position to where it was upon calling findNewline
 	S.pos = pos
 	S.offset = pos.Offset + 1
-	S.ch = '/'
+	S.next()
 
 	return newline
 }
@@ -577,6 +577,10 @@ scanAgain:
 			if S.ch == '/' || S.ch == '*' {
 				// comment
 				if S.insertSemi && S.findNewline(pos) {
+					// reset position to the beginning of the comment
+					S.pos = pos
+					S.offset = pos.Offset + 1
+					S.ch = '/'
 					S.insertSemi = false // newline consumed
 					return pos, token.SEMICOLON, semicolon
 				}
diff --git a/src/pkg/go/scanner/scanner_test.go b/src/pkg/go/scanner/scanner_test.go
index 6ea4b2d58e..83314a3aa1 100644
--- a/src/pkg/go/scanner/scanner_test.go
+++ b/src/pkg/go/scanner/scanner_test.go
@@ -392,6 +392,8 @@ var lines = []string{
 	"foo    $/*comment*/    \n",
 	"foo    $/*0*/ /*1*/ /*2*/    \n",
 	"foo	$/**/ /*-------------*/       /*----\n*/bar       $/*  \n*/baa",
+
+	"package main$\n\nfunc main() {\n\tif {\n\t\treturn /* */ }$\n}$\n",
 }
 
 
-- 
2.48.1