diff --git a/java/java-tests/testData/ide/plugins/pluginDescriptor/jar spaces.jar b/java/java-tests/testData/ide/plugins/pluginDescriptor/jar spaces.jar
new file mode 100644
index 000000000000..24b8f0daaf48
Binary files /dev/null and b/java/java-tests/testData/ide/plugins/pluginDescriptor/jar spaces.jar differ
diff --git a/java/java-tests/testData/ide/plugins/pluginDescriptor/spaces spaces/META-INF/plugin.xml b/java/java-tests/testData/ide/plugins/pluginDescriptor/spaces spaces/META-INF/plugin.xml
new file mode 100644
index 000000000000..fd9626d32976
--- /dev/null
+++ b/java/java-tests/testData/ide/plugins/pluginDescriptor/spaces spaces/META-INF/plugin.xml	
@@ -0,0 +1,6 @@
+<idea-plugin version="2">
+    <name>URLs Test</name>
+    <id>com.jetbrains.plugins.urls</id>
+    <idea-version since-build="10000"/>
+    <version>0.1</version>
+</idea-plugin>
\ No newline at end of file
diff --git a/platform/core-impl/src/com/intellij/ide/plugins/PluginManagerCore.java b/platform/core-impl/src/com/intellij/ide/plugins/PluginManagerCore.java
index 7cae6abfb550..a1d6a2b93426 100644
--- a/platform/core-impl/src/com/intellij/ide/plugins/PluginManagerCore.java
+++ b/platform/core-impl/src/com/intellij/ide/plugins/PluginManagerCore.java
@@ -55,6 +55,7 @@ import java.io.*;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
+import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.*;
@@ -917,13 +918,13 @@ public class PluginManagerCore {
   private static IdeaPluginDescriptorImpl loadDescriptorFromResource(@NotNull URL resource) {
     try {
       if (URLUtil.FILE_PROTOCOL.equals(resource.getProtocol())) {
-        File descriptorFile = new File(resource.toURI());
+        File descriptorFile = urlToFile(resource);
         File pluginDir = descriptorFile.getParentFile().getParentFile();
         return loadDescriptor(pluginDir, descriptorFile.getName());
       }
       else if (URLUtil.JAR_PROTOCOL.equals(resource.getProtocol())) {
         String path = resource.getFile();
-        File pluginJar = new File(new URL(path.substring(0, path.indexOf(URLUtil.JAR_SEPARATOR))).toURI());
+        File pluginJar = urlToFile(new URL(path.substring(0, path.indexOf(URLUtil.JAR_SEPARATOR))));
         return loadDescriptor(pluginJar, PathUtil.getFileName(path));
       }
     }
@@ -934,6 +935,20 @@ public class PluginManagerCore {
     return null;
   }
 
+  // work around corrupted URLs produced by File.getURL()
+  private static File urlToFile(URL url) throws URISyntaxException, MalformedURLException {
+    try {
+      return new File(url.toURI());
+    }
+    catch (URISyntaxException e) {
+      String str = url.toString();
+      if (str.indexOf(' ') > 0) {
+        return new File(new URL(StringUtil.replace(str, " ", "%20")).toURI());
+      }
+      throw e;
+    }
+  }
+
   private static void loadDescriptorsFromProperty(@NotNull List<IdeaPluginDescriptorImpl> result) {
     final String pathProperty = System.getProperty(PROPERTY_PLUGIN_PATH);
     if (pathProperty == null) return;
diff --git a/platform/platform-tests/testSrc/com/intellij/ide/plugins/PluginDescriptorTest.java b/platform/platform-tests/testSrc/com/intellij/ide/plugins/PluginDescriptorTest.java
index 52a9e8788dd9..c48fae6e2261 100644
--- a/platform/platform-tests/testSrc/com/intellij/ide/plugins/PluginDescriptorTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/ide/plugins/PluginDescriptorTest.java
@@ -16,13 +16,16 @@
 package com.intellij.ide.plugins;
 
 import com.intellij.openapi.application.ex.PathManagerEx;
+import com.intellij.util.lang.UrlClassLoader;
 import org.junit.Test;
 
 import java.io.File;
+import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
-import java.util.List;
+import java.util.Enumeration;
+import java.util.NoSuchElementException;
 
 import static org.junit.Assert.*;
 
@@ -54,9 +57,62 @@ public class PluginDescriptorTest {
   public void testFilteringDuplicates() throws MalformedURLException {
     URL[] urls = {
       new File(getTestDataPath(), "duplicate1.jar").toURI().toURL(),
-      new File(getTestDataPath(), "duplicate2.jar").toURI().toURL()
-    };
-    List<? extends IdeaPluginDescriptor> descriptors = PluginManagerCore.testLoadDescriptorsFromClassPath(new URLClassLoader(urls, null));
-    assertEquals(1, descriptors.size());
+      new File(getTestDataPath(), "duplicate2.jar").toURI().toURL()};
+    assertEquals(1, PluginManagerCore.testLoadDescriptorsFromClassPath(new URLClassLoader(urls, null)).size());
+  }
+
+  @Test
+  public void testUrlTolerance() throws MalformedURLException {
+    class SingleUrlEnumeration implements Enumeration<URL> {
+      private final URL myUrl;
+      private boolean hasMoreElements = true;
+
+      public SingleUrlEnumeration(URL url) {
+        myUrl = url;
+      }
+
+      @Override
+      public boolean hasMoreElements() {
+        return hasMoreElements;
+      }
+
+      @Override
+      public URL nextElement() {
+        if (!hasMoreElements) throw new NoSuchElementException();
+        hasMoreElements = false;
+        return myUrl;
+      }
+    }
+
+    class TestLoader extends UrlClassLoader {
+      private final URL myUrl;
+
+      public TestLoader(String prefix, String suffix) throws MalformedURLException {
+        super(build());
+        myUrl = new URL(prefix + new File(getTestDataPath()).toURI().toURL().toString() + suffix + "META-INF/plugin.xml");
+      }
+
+      @Override
+      public URL getResource(String name) {
+        return null;
+      }
+
+      @Override
+      public Enumeration<URL> getResources(String name) throws IOException {
+        return new SingleUrlEnumeration(myUrl);
+      }
+    }
+
+    ClassLoader loader1 = new TestLoader("", "/spaces%20spaces/");
+    assertEquals(1, PluginManagerCore.testLoadDescriptorsFromClassPath(loader1).size());
+
+    ClassLoader loader2 = new TestLoader("", "/spaces spaces/");
+    assertEquals(1, PluginManagerCore.testLoadDescriptorsFromClassPath(loader2).size());
+
+    ClassLoader loader3 = new TestLoader("jar:", "/jar%20spaces.jar!/");
+    assertEquals(1, PluginManagerCore.testLoadDescriptorsFromClassPath(loader3).size());
+
+    ClassLoader loader4 = new TestLoader("jar:", "/jar spaces.jar!/");
+    assertEquals(1, PluginManagerCore.testLoadDescriptorsFromClassPath(loader4).size());
   }
 }
\ No newline at end of file