From a7e57430802046d65c3e1e164969dbeec5891fc7 Mon Sep 17 00:00:00 2001
From: "Maxim.Mossienko" <Maxim.Mossienko@jetbrains.com>
Date: Fri, 17 Nov 2017 22:08:25 +0100
Subject: [PATCH] findResources("SomeDir/") fails (IDEA-182329)

---
 .../src/com/intellij/util/lang/ClassPath.java | 13 +++---
 .../util/lang/UrlClassLoaderTest.java         | 42 ++++++++++++++++++-
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/platform/util/src/com/intellij/util/lang/ClassPath.java b/platform/util/src/com/intellij/util/lang/ClassPath.java
index 03a76797f817..e9dc13257636 100644
--- a/platform/util/src/com/intellij/util/lang/ClassPath.java
+++ b/platform/util/src/com/intellij/util/lang/ClassPath.java
@@ -266,19 +266,16 @@ public class ClassPath {
       List<Loader> loaders = null;
 
       if (myCanUseCache && myAllUrlsWereProcessed) {
-        boolean nameIsDirectory = name.endsWith("/");
-        Collection<Loader> loadersSet = nameIsDirectory ? new SmartList<Loader>() : new LinkedHashSet<Loader>();
+        Collection<Loader> loadersSet = new LinkedHashSet<Loader>();
         myCache.iterateLoaders(name, ourLoaderCollector, loadersSet, this);
 
-        if (!nameIsDirectory) {
+        if (name.endsWith("/")) {
+          myCache.iterateLoaders(name.substring(0, name.length() - 1), ourLoaderCollector, loadersSet, this);
+        } else {
           myCache.iterateLoaders(name.concat("/"), ourLoaderCollector, loadersSet, this);
         }
 
-        if (nameIsDirectory) {
-          loaders = (List<Loader>)loadersSet;
-        } else {
-          loaders = new ArrayList<Loader>(loadersSet);
-        }
+        loaders = new ArrayList<Loader>(loadersSet);
       }
 
       myLoaders = loaders;
diff --git a/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java b/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
index 89c5e664636c..fd3cd2a2f56b 100644
--- a/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
+++ b/platform/util/testSrc/com/intellij/util/lang/UrlClassLoaderTest.java
@@ -17,8 +17,7 @@ package com.intellij.util.lang;
 
 import com.intellij.openapi.application.PathManager;
 import com.intellij.openapi.util.io.FileUtil;
-import com.intellij.util.ConcurrencyUtil;
-import com.intellij.util.ObjectUtils;
+import com.intellij.util.*;
 import com.intellij.util.containers.ContainerUtil;
 import org.junit.Test;
 
@@ -218,4 +217,43 @@ public class UrlClassLoaderTest {
       return loader.findResource(name);
     }
   }
+
+  @Test
+  public void testFindDirWhenUsingCache() throws IOException {
+    int counter = 1;
+    for (String dirName : new String[]{ "dir", "dir/", "dir.class", "dir.class/"}) {
+      for(String resourceName: new String[] {"a.class", "a.txt"} ) {
+        File root = FileUtil.createTempDirectory("testFindDirWhenUsingCache", String.valueOf(counter++));
+        File subDir = createTestDir(root, dirName);
+        createTestFile(subDir, resourceName);
+
+        URL url = root.toURI().toURL();
+        URLClassLoader standardCl = new URLClassLoader(new URL[] {url});
+
+        try {
+          Enumeration<URL> resources = standardCl.findResources(dirName);
+          assertTrue(resources.hasMoreElements());
+          URL expectedResourceUrl = resources.nextElement();
+
+          withCustomCachedClassloader(url, (customCl) -> {
+            assertNull(customCl.findResource("SomeNonExistentResource.resource"));
+            checkResourceUrlIsTheSame(customCl, dirName, expectedResourceUrl);
+          });
+          withCustomCachedClassloader(url, (customCl) -> checkResourceUrlIsTheSame(customCl, dirName, expectedResourceUrl));
+        } finally {
+          standardCl.close();
+        }
+      }
+    }
+  }
+
+  private static void checkResourceUrlIsTheSame(UrlClassLoader customCl, String resourceName, URL expectedResourceUrl) throws IOException {
+    Enumeration<URL> customClResources = customCl.findResources(resourceName);
+    assertTrue(customClResources.hasMoreElements());
+    assertEquals(expectedResourceUrl, customClResources.nextElement());
+  }
+
+  private static void withCustomCachedClassloader(URL url, ThrowableConsumer<UrlClassLoader, IOException> testAction) throws IOException {
+    testAction.consume(UrlClassLoader.build().useCache().urls(url).get());
+  }
 }
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