[platform] resolves symlinks when checking VM options file location

https://intellij-support.jetbrains.com/hc/en-us/community/posts/115000784344-Do-phpstorm64-vmoptions-in-config-1-override-append-or-2-completely-replace-the-defaults-in-IDE-HOME-bin-

platform/platform-impl/src/com/intellij/diagnostic/VMOptions.java

@@ -1,17 +1,5 @@
 /*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * 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.
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
  */
 package com.intellij.diagnostic;
 
@@ -175,7 +163,7 @@ public class VMOptions {
     }
 
     vmOptionsFile = new File(vmOptionsFile).getAbsolutePath();
-    if (!FileUtil.isAncestor(PathManager.getHomePath(), vmOptionsFile, true)) {
+    if (!FileUtil.isAncestor(canonicalPath(PathManager.getHomePath()), canonicalPath(vmOptionsFile), true)) {
       // a file is located outside the IDE installation - meaning it is safe to overwrite
       return new File(vmOptionsFile);
     }
@@ -192,6 +180,15 @@ public class VMOptions {
     return new File(location, fileName);
   }
 
+  private static String canonicalPath(String path) {
+    try {
+      return new File(path).getCanonicalPath();
+    }
+    catch (IOException e) {
+      return path;
+    }
+  }
+
   //<editor-fold desc="Deprecated stuff.">
   /** @deprecated use {@link #readOption(MemoryKind, boolean)} (to be removed in IDEA 2018) */
   public static int readXmx() {