diff --git a/java/java-tests/testData/vfs/sample.jar b/java/java-tests/testData/vfs/sample.jar
new file mode 100644
index 000000000000..acbe629b519d
Binary files /dev/null and b/java/java-tests/testData/vfs/sample.jar differ
diff --git a/platform/core-impl/src/com/intellij/openapi/vfs/impl/ZipHandlerBase.java b/platform/core-impl/src/com/intellij/openapi/vfs/impl/ZipHandlerBase.java
index b250d3ff26d5..94991d5b9238 100644
--- a/platform/core-impl/src/com/intellij/openapi/vfs/impl/ZipHandlerBase.java
+++ b/platform/core-impl/src/com/intellij/openapi/vfs/impl/ZipHandlerBase.java
@@ -50,7 +50,7 @@ public abstract class ZipHandlerBase extends ArchiveHandler {
   }
 
   @NotNull
-  protected Map<String, EntryInfo> buildEntryMapForZipFile(ZipFile zip) {
+  protected Map<String, EntryInfo> buildEntryMapForZipFile(@NotNull ZipFile zip) {
     Map<String, EntryInfo> map = new ZipEntryMap(zip.size());
     map.put("", createRootEntry());
 
@@ -80,6 +80,7 @@ public abstract class ZipHandlerBase extends ArchiveHandler {
     EntryInfo info = map.get(entryName);
     if (info != null) return info;
 
+    entryName = StringUtil.trimStart(entryName, "/");
     Trinity<String, String, String> path = splitPathAndFix(entryName);
     EntryInfo parentInfo = getOrCreate(path.first, map, zip);
     if (".".equals(path.second)) {
diff --git a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/JarFileSystemTest.java b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/JarFileSystemTest.java
index 7bf992a9cbbf..701e360f1c46 100644
--- a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/JarFileSystemTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/local/JarFileSystemTest.java
@@ -3,6 +3,7 @@ package com.intellij.openapi.vfs.local;
 
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.PathManager;
+import com.intellij.openapi.application.ex.PathManagerEx;
 import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.util.io.FileAttributes;
 import com.intellij.openapi.util.io.FileUtil;
@@ -17,6 +18,7 @@ import com.intellij.openapi.vfs.newvfs.BulkFileListener;
 import com.intellij.openapi.vfs.newvfs.events.VFileContentChangeEvent;
 import com.intellij.openapi.vfs.newvfs.events.VFileEvent;
 import com.intellij.testFramework.PlatformTestUtil;
+import com.intellij.testFramework.UsefulTestCase;
 import com.intellij.testFramework.fixtures.BareTestFixtureTestCase;
 import com.intellij.testFramework.rules.TempDirectory;
 import com.intellij.util.containers.ContainerUtil;
@@ -297,6 +299,19 @@ public class JarFileSystemTest extends BareTestFixtureTestCase {
     }
   }
 
+  @Test
+  public void testCrazyJarWithDuplicateEntriesMustNotCrashAnything() {
+    String jarPath = PathManagerEx.getTestDataPath() + "/vfs/sample.jar";
+    VirtualFile vFile = LocalFileSystem.getInstance().refreshAndFindFileByPath(jarPath);
+    assertNotNull(vFile);
+
+    VirtualFile jarRoot = JarFileSystem.getInstance().getRootByLocal(vFile);
+    assertNotNull(jarRoot);
+    String[] children = JarFileSystem.getInstance().list(jarRoot);
+    assertEquals("com", UsefulTestCase.assertOneElement(children));
+    assertEquals("Hello.class", UsefulTestCase.assertOneElement(JarFileSystem.getInstance().list(jarRoot.findFileByRelativePath("com"))));
+  }
+
   @NotNull
   private static VirtualFile findByPath(String path) {
     VirtualFile file = JarFileSystem.getInstance().findFileByPath(path);