[FIX JENKINS-48407] Test to check we have the expected permissions

core/src/test/java/hudson/util/AtomicFileWriterTest.java

@@ -6,20 +6,36 @@ import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
+import org.jvnet.hudson.test.Issue;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.nio.file.attribute.PosixFilePermission;
+import java.util.EnumSet;
+import java.util.Set;
 
 import static org.hamcrest.core.StringContains.*;
+import static java.nio.file.attribute.PosixFilePermission.GROUP_EXECUTE;
+import static java.nio.file.attribute.PosixFilePermission.GROUP_READ;
+import static java.nio.file.attribute.PosixFilePermission.GROUP_WRITE;
+import static java.nio.file.attribute.PosixFilePermission.OTHERS_EXECUTE;
+import static java.nio.file.attribute.PosixFilePermission.OTHERS_READ;
+import static java.nio.file.attribute.PosixFilePermission.OTHERS_WRITE;
+import static java.nio.file.attribute.PosixFilePermission.OWNER_EXECUTE;
+import static java.nio.file.attribute.PosixFilePermission.OWNER_READ;
+import static java.nio.file.attribute.PosixFilePermission.OWNER_WRITE;
+import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeThat;
 
 public class AtomicFileWriterTest {
     private static final String PREVIOUS = "previous value \n blah";
@@ -124,4 +140,55 @@ public class AtomicFileWriterTest {
                        containsString("exists and is neither a directory nor a symlink to a directory"));
         }
     }
+
+    @Issue("JENKINS-48407")
+    @Test
+    public void checkPermissions() throws IOException, InterruptedException {
+
+        final File newFile = tmp.newFile();
+
+        // Check Posix calls are supported (to avoid running this test on Windows for instance)
+        boolean posixSupported = true;
+        try {
+            Files.getPosixFilePermissions(newFile.toPath());
+        } catch (UnsupportedOperationException e) {
+            posixSupported = false;
+        }
+        assumeThat(posixSupported, is(true));
+
+        // given
+        final Set<PosixFilePermission> givenPermissions = EnumSet.of(OWNER_READ,
+                                                                     OWNER_WRITE,
+                                                                     GROUP_READ,
+                                                                     GROUP_WRITE,
+                                                                     OTHERS_READ
+        );
+
+        final Set<PosixFilePermission> notGivenPermissions = EnumSet.of(OWNER_EXECUTE,
+                                                                        GROUP_EXECUTE,
+                                                                        OTHERS_WRITE,
+                                                                        OTHERS_EXECUTE);
+
+        Files.setPosixFilePermissions(newFile.toPath(), givenPermissions);
+        Path filePath = newFile.toPath();
+
+        // when
+        AtomicFileWriter w = new AtomicFileWriter(filePath, StandardCharsets.UTF_8);
+        w.write("whatever");
+        w.commit();
+
+        // then
+        assertFalse(w.getTemporaryPath().toFile().exists());
+        assertTrue(filePath.toFile().exists());
+
+        final Set<PosixFilePermission> posixFilePermissions = Files.getPosixFilePermissions(filePath);
+
+        for (PosixFilePermission perm : givenPermissions) {
+            assertTrue("missing: " + perm, posixFilePermissions.contains(perm));
+        }
+
+        for (PosixFilePermission perm : notGivenPermissions) {
+            assertFalse("should not be allowed: " + perm, posixFilePermissions.contains(perm));
+        }
+    }
 }