fixed testDeleteFail - using chmod on unixes

platform/util/testSrc/com/intellij/openapi/util/io/FileUtilHeavyTest.java

@@ -181,22 +181,33 @@ public class FileUtilHeavyTest {
   }
 
   @Test
-  public void testDeleteFail() throws IOException {
+  public void testDeleteFail() throws Exception {
     File targetDir = IoTestUtil.createTestDir(myTempDirectory, "failed_delete");
     File file = IoTestUtil.createTestFile(targetDir, "file");
-    // lock file
-    @SuppressWarnings("IOResourceOpenedButNotSafelyClosed")
-    RandomAccessFile rw = new RandomAccessFile(file, "rw");
-    FileLock lock = null;
-    try {
-      lock = rw.getChannel().tryLock();
-      assertFalse(FileUtil.delete(file));
+
+    if (SystemInfo.isWindows) {
+      @SuppressWarnings("IOResourceOpenedButNotSafelyClosed")
+      RandomAccessFile rw = new RandomAccessFile(file, "rw");
+      FileLock lock = null;
+      try {
+        lock = rw.getChannel().tryLock();
+        assertFalse(FileUtil.delete(file));
+      }
+      finally {
+        if (lock != null) {
+          lock.release();
+        }
+        rw.close();
+      }
     }
-    finally {
-      if (lock != null) {
-        lock.release();
+    else { // on unix use chmod
+      assertEquals(0, new ProcessBuilder("chmod", "a-w", file.getParentFile().getPath()).start().waitFor());
+      try {
+        assertFalse(FileUtil.delete(file));
+      }
+      finally {
+        assertEquals(0, new ProcessBuilder("chmod", "a+w", file.getParentFile().getPath()).start().waitFor());
       }
-      rw.close();
     }
   }