internal/fs: Use filepath.Clean() on string parameters in HasFilepathPrefix

Previously strings were being cleaned with strings.TrimSuffix() to remove
trailing separators. However, filepath.Clean() additionally removes
directory navigation symbols (e.g. './', '../') and repeated separators.

TestHasFilepathPrefix has additional test cases added to ensure trailing,
and repeated separators are handled correctly.

Fixes #1946

Author: jpentland

internal/fs/fs.go

@@ -61,8 +61,8 @@ func HasFilepathPrefix(path, prefix string) (bool, error) {
 		dn = filepath.Dir(path)
 	}
 
-	dn = strings.TrimSuffix(dn, string(os.PathSeparator))
-	prefix = strings.TrimSuffix(prefix, string(os.PathSeparator))
+	dn = filepath.Clean(dn)
+	prefix = filepath.Clean(prefix)
 
 	// [1:] in the lines below eliminates empty string on *nix and volume name on Windows
 	dirs := strings.Split(dn, string(os.PathSeparator))[1:]

internal/fs/fs_test.go

@@ -47,12 +47,19 @@ func TestHasFilepathPrefix(t *testing.T) {
 		dir2 = dir
 	}
 
+	// For testing trailing and repeated separators
+	sep := string(os.PathSeparator)
+
 	cases := []struct {
 		path   string
 		prefix string
 		want   bool
 	}{
 		{filepath.Join(dir, "a", "b"), filepath.Join(dir2), true},
+		{filepath.Join(dir, "a", "b"), dir2 + sep + sep + "a", true},
+		{filepath.Join(dir, "a", "b"), filepath.Join(dir2, "a") + sep, true},
+		{filepath.Join(dir, "a", "b") + sep, filepath.Join(dir2), true},
+		{dir + sep + sep + filepath.Join("a", "b"), filepath.Join(dir2, "a"), true},
 		{filepath.Join(dir, "a", "b"), filepath.Join(dir2, "a"), true},
 		{filepath.Join(dir, "a", "b"), filepath.Join(dir2, "a", "b"), true},
 		{filepath.Join(dir, "a", "b"), filepath.Join(dir2, "c"), false},