client: use canonical url path in request

The main change is that it keeps the trailing slash. This helps
auth feature to judge path permission accurately.

pkg/pathutil/path_test.go

@@ -0,0 +1,38 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pathutil
+
+import "testing"
+
+func TestCanonicalURLPath(t *testing.T) {
+	tests := []struct {
+		p  string
+		wp string
+	}{
+		{"/a", "/a"},
+		{"", "/"},
+		{"a", "/a"},
+		{"//a", "/a"},
+		{"/a/.", "/a"},
+		{"/a/..", "/"},
+		{"/a/", "/a/"},
+		{"/a//", "/a/"},
+	}
+	for i, tt := range tests {
+		if g := CanonicalURLPath(tt.p); g != tt.wp {
+			t.Errorf("#%d: canonical path = %s, want %s", i, g, tt.wp)
+		}
+	}
+}