[FIXED JENKINS-17271] Util.deleteFile should give a concrete reason for failure.

changelog.html

@@ -58,6 +58,9 @@ Upcoming changes</a>
   <li class=rfe>
     Option to make the build not fail if there is nothing to archive.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-10502">issue 10502</a>)
+  <li class=rfe>
+    Better report file deletion failures.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-17271">issue 17271</a>)
   <li class=bug>
     Master node mode not correctly displayed in <code>/computer/(master)/configure</code>.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-17263">issue 17263</a>)

core/src/main/java/hudson/Util.java

@@ -33,7 +33,6 @@ import hudson.os.PosixAPI;
 import hudson.util.IOException2;
 import hudson.util.QuotedStringTokenizer;
 import hudson.util.VariableResolver;
-import hudson.util.jna.Kernel32;
 import hudson.util.jna.WinIOException;
 import jenkins.model.Jenkins;
 import org.apache.commons.io.IOUtils;
@@ -237,6 +236,18 @@ public class Util {
 
             if(!f.delete() && f.exists()) {
                 // trouble-shooting.
+                try {
+                    Class.forName("java.nio.file.Files").getMethod("delete", Class.forName("java.nio.file.Path")).invoke(null, File.class.getMethod("toPath").invoke(f));
+                } catch (InvocationTargetException x) {
+                    Throwable x2 = x.getCause();
+                    if (x2 instanceof IOException) {
+                        // may have a specific exception message
+                        throw (IOException) x2;
+                    }
+                    // else suppress
+                } catch (Throwable x) {
+                    // linkage errors, etc.; suppress
+                }
                 // see http://www.nabble.com/Sometimes-can%27t-delete-files-from-hudson.scm.SubversionSCM%24CheckOutTask.invoke%28%29-tt17333292.html
                 // I suspect other processes putting files in this directory
                 File[] files = f.listFiles();

core/src/test/java/hudson/UtilTest.java

@@ -37,6 +37,9 @@ import org.junit.Test;
 import org.jvnet.hudson.test.Bug;
 
 import hudson.util.StreamTaskListener;
+import java.io.FileOutputStream;
+import java.io.OutputStream;
+import org.junit.internal.AssumptionViolatedException;
 
 /**
  * @author Kohsuke Kawaguchi
@@ -230,6 +233,31 @@ public class UtilTest {
         }
     }
 
+    @Test public void deleteFile() throws Exception {
+        Assume.assumeTrue(Functions.isWindows());
+        Class<?> c;
+        try {
+            c = Class.forName("java.nio.file.FileSystemException");
+        } catch (ClassNotFoundException x) {
+            throw new AssumptionViolatedException("prior to JDK 7", x);
+        }
+        File d = Util.createTempDir();
+        try {
+            File f = new File(d, "f");
+            OutputStream os = new FileOutputStream(f);
+            try {
+                Util.deleteFile(f);
+                fail("should not have been deletable");
+            } catch (IOException x) {
+                assertEquals(c, x.getClass());
+            } finally {
+                os.close();
+            }
+        } finally {
+            Util.deleteRecursive(d);
+        }
+    }
+
     @Test
     public void testHtmlEscape() {
         assertEquals("<br>", Util.escape("\n"));