From 1934fc73e8608a846afcf4e6e06aa4d0b61cac56 Mon Sep 17 00:00:00 2001
From: Mike Danese <mikedanese@google.com>
Date: Tue, 5 Jan 2016 11:26:53 -0800
Subject: [PATCH] mungedocs: fix ignored errors in link checker

Before this change the link checker would ignore errors in a file if
the last link in a file was correct. The last link would wipe out the
error variable and set it to nil. Furthermore, it replaced errored
links with the empty string.

If we find an error that we can't correct, append the error message to
an an errs slice and leave the string as is.

Signed-off-by: Mike Danese <mikedanese@google.com>
---
 cmd/mungedocs/links.go | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/cmd/mungedocs/links.go b/cmd/mungedocs/links.go
index e7c95705a5a..9fb82ac16a7 100644
--- a/cmd/mungedocs/links.go
+++ b/cmd/mungedocs/links.go
@@ -17,6 +17,7 @@ limitations under the License.
 package main
 
 import (
+	"errors"
 	"fmt"
 	"net/url"
 	"os"
@@ -33,11 +34,12 @@ var (
 )
 
 func processLink(in string, filePath string) (string, error) {
-	var err error
+	var errs []string
 	out := linkRE.ReplaceAllStringFunc(in, func(in string) string {
+		var err error
 		match := linkRE.FindStringSubmatch(in)
 		if match == nil {
-			err = fmt.Errorf("Detected this line had a link, but unable to parse, %v", in)
+			errs = append(errs, fmt.Sprintf("Detected this line had a link, but unable to parse, %v", in))
 			return ""
 		}
 		// match[0] is the entire expression;
@@ -56,8 +58,8 @@ func processLink(in string, filePath string) (string, error) {
 
 		u, terr := url.Parse(linkText)
 		if terr != nil {
-			err = fmt.Errorf("link %q is unparsable: %v", linkText, terr)
-			return ""
+			errs = append(errs, fmt.Sprintf("link %q is unparsable: %v", linkText, terr))
+			return in
 		}
 
 		if u.Host != "" && u.Host != "github.com" {
@@ -69,8 +71,8 @@ func processLink(in string, filePath string) (string, error) {
 		if u.Path != "" && !strings.HasPrefix(linkText, "TODO:") {
 			newPath, targetExists := checkPath(filePath, path.Clean(u.Path))
 			if !targetExists {
-				err = fmt.Errorf("%q: target not found", linkText)
-				return ""
+				errs = append(errs, fmt.Sprintf("%q: target not found", linkText))
+				return in
 			}
 			u.Path = newPath
 			if strings.HasPrefix(u.Path, "/") {
@@ -87,7 +89,8 @@ func processLink(in string, filePath string) (string, error) {
 				dir := path.Dir(filePath)
 				suggestedVisibleText, err = makeRepoRelative(path.Join(dir, u.Path), filePath)
 				if err != nil {
-					return ""
+					errs = append(errs, fmt.Sprintf("%q: unable to make path relative", filePath))
+					return in
 				}
 			} else {
 				suggestedVisibleText = u.Path
@@ -109,8 +112,8 @@ func processLink(in string, filePath string) (string, error) {
 
 		return fmt.Sprintf("[%s](%s)", visibleText, linkText+altText)
 	})
-	if out == "" {
-		return in, err
+	if len(errs) != 0 {
+		return "", errors.New(strings.Join(errs, ","))
 	}
 	return out, nil
 }