Make dt_runpath work for libraries opened from apk

This patch also fixes realpath for libraries opened directly
from apks.

Bug: http://b/21960914
Bug: http://b/21961857
Change-Id: I35ade661c87f1d448191f385811f6e9fd3cacf11
diff --git a/linker/tests/linker_utils_test.cpp b/linker/tests/linker_utils_test.cpp
new file mode 100644
index 0000000..458474e
--- /dev/null
+++ b/linker/tests/linker_utils_test.cpp
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <gtest/gtest.h>
+
+#include "../linker_utils.h"
+
+TEST(linker_utils, normalize_path_smoke) {
+  std::string output;
+  ASSERT_TRUE(normalize_path("/../root///dir/.///dir2/somedir/../zipfile!/dir/dir9//..///afile", &output));
+  ASSERT_EQ("/root/dir/dir2/zipfile!/dir/afile", output);
+
+  ASSERT_TRUE(normalize_path("/../root///dir/.///dir2/somedir/.../zipfile!/.dir/dir9//..///afile", &output));
+  ASSERT_EQ("/root/dir/dir2/somedir/.../zipfile!/.dir/afile", output);
+
+  ASSERT_TRUE(normalize_path("/root/..", &output));
+  ASSERT_EQ("/", output);
+
+  ASSERT_TRUE(normalize_path("/root/notroot/..", &output));
+  ASSERT_EQ("/root/", output);
+
+  ASSERT_TRUE(normalize_path("/a/../../b", &output));
+  ASSERT_EQ("/b", output);
+
+  output = "unchanged";
+  ASSERT_FALSE(normalize_path("root///dir/.///dir2/somedir/../zipfile!/dir/dir9//..///afile", &output));
+  ASSERT_EQ("unchanged", output);
+}