path/filepath: keep walking if EvalSymlinks returns symlink

Fixes #13582

Change-Id: I220f3c7b9511b3c080874f5c42f2a431fdddcbb7
Reviewed-on: https://go-review.googlesource.com/17794
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

1 files changed, 20 insertions, 5 deletions

diff --git a/src/path/filepath/symlink.go b/src/path/filepath/symlink.go
index dc7e9eb9bf..bc287c5ecb 100644
--- a/src/path/filepath/symlink.go
+++ b/src/path/filepath/symlink.go
@@ -85,7 +85,6 @@ func walkLinks(path string, linksWalked *int) (string, error) {
 			return newpath, nil
 		}
 		return Join(newdir, newpath), nil
-
 	}
 }
 
@@ -94,9 +93,25 @@ func walkSymlinks(path string) (string, error) {
 		return path, nil
 	}
 	var linksWalked int // to protect against cycles
-	newpath, err := walkLinks(path, &linksWalked)
-	if err != nil {
-		return "", err
+	for {
+		i := linksWalked
+		newpath, err := walkLinks(path, &linksWalked)
+		if err != nil {
+			return "", err
+		}
+		if runtime.GOOS == "windows" {
+			// walkLinks(".", ...) always retuns "." on unix.
+			// But on windows it returns symlink target, if current
+			// directory is a symlink. Stop the walk, if symlink
+			// target is not absolute path, and return "."
+			// to the caller (just like unix does).
+			if path == "." && !IsAbs(newpath) {
+				return ".", nil
+			}
+		}
+		if i == linksWalked {
+			return Clean(newpath), nil
+		}
+		path = newpath
 	}
-	return Clean(newpath), nil
 }