From 992185430117426719be1ba28af9143a219861d5 Mon Sep 17 00:00:00 2001
From: Maas van den Berg <maasvdberg@gmail.com>
Date: Mon, 16 Nov 2009 20:58:42 +0300
Subject: [PATCH] IDEADEV-41386: When configuring Java SDK, resolve symbolic
 links and remove duplicate entries.

---
 .../openapi/projectRoots/impl/JavaSdkImpl.java | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/java/java-impl/src/com/intellij/openapi/projectRoots/impl/JavaSdkImpl.java b/java/java-impl/src/com/intellij/openapi/projectRoots/impl/JavaSdkImpl.java
index a4527887c4b5..f44bd5635196 100644
--- a/java/java-impl/src/com/intellij/openapi/projectRoots/impl/JavaSdkImpl.java
+++ b/java/java-impl/src/com/intellij/openapi/projectRoots/impl/JavaSdkImpl.java
@@ -32,6 +32,7 @@ import org.jetbrains.annotations.Nullable;
 import javax.swing.*;
 import java.io.File;
 import java.io.FileFilter;
+import java.io.IOException;
 import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -340,18 +341,25 @@ public class JavaSdkImpl extends JavaSdk {
       jarDirs = new File[]{jreLibEndorsedFile, jreLibFile, jreLibExtFile};
     }
 
-    ArrayList<File> childrenList = new ArrayList<File>();
+    Set<File> childrenSet = new LinkedHashSet<File>();
     for (File jarDir : jarDirs) {
       if (jarDir != null && jarDir.isDirectory()) {
-        File[] files = jarDir.listFiles(jarFileFilter);
-        for (File file1 : files) {
-          childrenList.add(file1);
+        File[] jarFiles = jarDir.listFiles(jarFileFilter);
+        for (File jarFile : jarFiles) {
+          try {
+            // File.getCanonicalFile() allows us to filter out duplicate (symbolically linked) jar files,
+            // commonly found in osx JDK distributions
+            childrenSet.add(jarFile.getCanonicalFile());
+          }
+          catch (IOException e) {
+            // Symbolic links may fail to resolve. Just skip those jars as we won't be able to find virtual file in this case anyway. 
+          }
         }
       }
     }
 
     ArrayList<VirtualFile> result = new ArrayList<VirtualFile>();
-    for (File child : childrenList) {
+    for (File child : childrenSet) {
       String url = JarFileSystem.PROTOCOL_PREFIX + child.getAbsolutePath().replace(File.separatorChar, '/') + JarFileSystem.JAR_SEPARATOR;
       VirtualFile vFile = VirtualFileManager.getInstance().findFileByUrl(url);
       if (vFile != null) {