1 files changed, 18 insertions, 8 deletions
diff --git a/guava/src/com/google/common/io/FileBackedOutputStream.java b/guava/src/com/google/common/io/FileBackedOutputStream.java
index 9912e2fcd..dd297e90a 100644
--- a/guava/src/com/google/common/io/FileBackedOutputStream.java
+++ b/guava/src/com/google/common/io/FileBackedOutputStream.java
@@ -14,12 +14,15 @@
 
 package com.google.common.io;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static java.util.Objects.requireNonNull;
 
 import com.google.common.annotations.Beta;
 import com.google.common.annotations.GwtIncompatible;
+import com.google.common.annotations.J2ktIncompatible;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.errorprone.annotations.concurrent.GuardedBy;
+import com.google.j2objc.annotations.J2ObjCIncompatible;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -34,6 +37,14 @@ import javax.annotation.CheckForNull;
  * An {@link OutputStream} that starts buffering to a byte array, but switches to file buffering
  * once the data reaches a configurable size.
  *
+ * <p>When this stream creates a temporary file, it restricts the file's permissions to the current
+ * user or, in the case of Android, the current app. If that is not possible (as is the case under
+ * the very old Android Ice Cream Sandwich release), then this stream throws an exception instead of
+ * creating a file that would be more accessible. (This behavior is new in Guava 32.0.0. Previous
+ * versions would create a file that is more accessible, as discussed in <a
+ * href="https://github.com/google/guava/issues/2575">Guava issue 2575</a>. TODO: b/283778848 - Fill
+ * in CVE number once it's available.)
+ *
  * <p>Temporary files created by this stream may live in the local filesystem until either:
  *
  * <ul>
@@ -51,13 +62,14 @@ import javax.annotation.CheckForNull;
  * @since 1.0
  */
 @Beta
+@J2ktIncompatible
 @GwtIncompatible
+@J2ObjCIncompatible
 @ElementTypesAreNonnullByDefault
 public final class FileBackedOutputStream extends OutputStream {
   private final int fileThreshold;
   private final boolean resetOnFinalize;
   private final ByteSource source;
-  @CheckForNull private final File parentDirectory;
 
   @GuardedBy("this")
   private OutputStream out;
@@ -93,6 +105,7 @@ public final class FileBackedOutputStream extends OutputStream {
    * {@link ByteSource} returned by {@link #asByteSource} is finalized.
    *
    * @param fileThreshold the number of bytes before the stream should switch to buffering to a file
+   * @throws IllegalArgumentException if {@code fileThreshold} is negative
    */
   public FileBackedOutputStream(int fileThreshold) {
     this(fileThreshold, false);
@@ -105,16 +118,13 @@ public final class FileBackedOutputStream extends OutputStream {
    * @param fileThreshold the number of bytes before the stream should switch to buffering to a file
    * @param resetOnFinalize if true, the {@link #reset} method will be called when the {@link
    *     ByteSource} returned by {@link #asByteSource} is finalized.
+   * @throws IllegalArgumentException if {@code fileThreshold} is negative
    */
   public FileBackedOutputStream(int fileThreshold, boolean resetOnFinalize) {
-    this(fileThreshold, resetOnFinalize, null);
-  }
-
-  private FileBackedOutputStream(
-      int fileThreshold, boolean resetOnFinalize, @CheckForNull File parentDirectory) {
+    checkArgument(
+        fileThreshold >= 0, "fileThreshold must be non-negative, but was %s", fileThreshold);
     this.fileThreshold = fileThreshold;
     this.resetOnFinalize = resetOnFinalize;
-    this.parentDirectory = parentDirectory;
     memory = new MemoryOutput();
     out = memory;
 
@@ -225,7 +235,7 @@ public final class FileBackedOutputStream extends OutputStream {
   @GuardedBy("this")
   private void update(int len) throws IOException {
     if (memory != null && (memory.getCount() + len > fileThreshold)) {
-      File temp = File.createTempFile("FileBackedOutputStream", null, parentDirectory);
+      File temp = TempFileCreator.INSTANCE.createTempFile("FileBackedOutputStream");
       if (resetOnFinalize) {
         // Finalizers are not guaranteed to be called on system shutdown;
         // this is insurance.