"merge"

android/guava-tests/test/com/google/common/io/FilesCreateTempDirTest.java

@@ -66,31 +66,39 @@ public void testCreateTempDir() throws IOException {
   }
 
   public void testBogusSystemPropertiesUsername() {
+    if (isAndroid()) {
+      /*
+       * The test calls directly into the "ACL-based filesystem" code, which isn't available under
+       * old versions of Android. Since Android doesn't use that code path, anyway, there's no need
+       * to test it.
+       */
+      return;
+    }
+
     /*
      * Only under Windows (or hypothetically when running with some other non-POSIX, ACL-based
-     * filesystem) do we look up the username. Thus, this test doesn't test anything interesting
-     * under most environments.
+     * filesystem) does our prod code look up the username. Thus, this test doesn't necessarily test
+     * anything interesting under most environments. Still, we can run it (except for Android, at
+     * least old versions), so we mostly do. This is useful because we don't actually run our CI on
+     * Windows under Java 8, at least as of this writing.
      *
-     * Under Windows, we test that:
+     * Under Windows in particular, we want to test that:
      *
      * - Under Java 9+, createTempDir() succeeds because it can look up the *real* username, rather
      * than relying on the one from the system property.
      *
      * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
      * system property.
-     *
-     * However: Note that we don't actually run our CI on Windows under Java 8, at least as of this
-     * writing.
      */
-    boolean isJava8OnWindows = JAVA_SPECIFICATION_VERSION.value().equals("1.8") && isWindows();
+    boolean isJava8 = JAVA_SPECIFICATION_VERSION.value().equals("1.8");
 
     String save = System.getProperty("user.name");
     System.setProperty("user.name", "-this-is-definitely-not-the-username-we-are-running-as//?");
     try {
       TempFileCreator.testMakingUserPermissionsFromScratch();
-      assertThat(isJava8OnWindows).isFalse();
-    } catch (IOException expectedIfJavaWindows8) {
-      assertThat(isJava8OnWindows).isTrue();
+      assertThat(isJava8).isFalse();
+    } catch (IOException expectedIfJava8) {
+      assertThat(isJava8).isTrue();
     } finally {
       System.setProperty("user.name", save);
     }

android/guava/src/com/google/common/io/TempFileCreator.java

@@ -105,7 +105,10 @@ private static TempFileCreator pickSecureCreator() {
 
   /**
    * Creates the permissions normally used for Windows filesystems, looking up the user afresh, even
-   * if previous calls have initialized the PermissionSupplier fields.
+   * if previous calls have initialized the {@code PermissionSupplier} fields.
+   *
+   * <p>This lets us test the effects of different values of the {@code user.name} system property
+   * without needing a separate VM or classloader.
    */
   @IgnoreJRERequirement // used only when Path is available (and only from tests)
   @VisibleForTesting

guava-tests/test/com/google/common/io/FilesCreateTempDirTest.java

@@ -66,31 +66,39 @@ public void testCreateTempDir() throws IOException {
   }
 
   public void testBogusSystemPropertiesUsername() {
+    if (isAndroid()) {
+      /*
+       * The test calls directly into the "ACL-based filesystem" code, which isn't available under
+       * old versions of Android. Since Android doesn't use that code path, anyway, there's no need
+       * to test it.
+       */
+      return;
+    }
+
     /*
      * Only under Windows (or hypothetically when running with some other non-POSIX, ACL-based
-     * filesystem) do we look up the username. Thus, this test doesn't test anything interesting
-     * under most environments.
+     * filesystem) does our prod code look up the username. Thus, this test doesn't necessarily test
+     * anything interesting under most environments. Still, we can run it (except for Android, at
+     * least old versions), so we mostly do. This is useful because we don't actually run our CI on
+     * Windows under Java 8, at least as of this writing.
      *
-     * Under Windows, we test that:
+     * Under Windows in particular, we want to test that:
      *
      * - Under Java 9+, createTempDir() succeeds because it can look up the *real* username, rather
      * than relying on the one from the system property.
      *
      * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
      * system property.
-     *
-     * However: Note that we don't actually run our CI on Windows under Java 8, at least as of this
-     * writing.
      */
-    boolean isJava8OnWindows = JAVA_SPECIFICATION_VERSION.value().equals("1.8") && isWindows();
+    boolean isJava8 = JAVA_SPECIFICATION_VERSION.value().equals("1.8");
 
     String save = System.getProperty("user.name");
     System.setProperty("user.name", "-this-is-definitely-not-the-username-we-are-running-as//?");
     try {
       TempFileCreator.testMakingUserPermissionsFromScratch();
-      assertThat(isJava8OnWindows).isFalse();
-    } catch (IOException expectedIfJavaWindows8) {
-      assertThat(isJava8OnWindows).isTrue();
+      assertThat(isJava8).isFalse();
+    } catch (IOException expectedIfJava8) {
+      assertThat(isJava8).isTrue();
     } finally {
       System.setProperty("user.name", save);
     }