DO NOT MERGE) ExifInterface: Make saveAttributes throw an exception before change

ExifInterface object can be created with a unsupported file format.
If saveAttribute is called with an unsupported file format, ExifInterface
makes the file corrupted. This CL prevents those cases by throwing
an exception before making any change on the file.

Bug: 30936376
Change-Id: I115a42601c774062485974042464abb0d65c35e9
(cherry picked from commit a8f9a075b14c526a0de75c2ade81ebc4e05e4ef8)
(cherry picked from commit 56ea7b490107e4531ab4db6f74671c34b5c59fd3)

1 files changed, 8 insertions, 5 deletions

diff --git a/media/java/android/media/ExifInterface.java b/media/java/android/media/ExifInterface.java
index 4848630baacf..56af57aa8e96 100644
--- a/media/java/android/media/ExifInterface.java
+++ b/media/java/android/media/ExifInterface.java
@@ -679,14 +679,14 @@ public class ExifInterface {
             if (value instanceof long[]) {
                 long[] array = (long[]) value;
                 if (array.length == 1) {
-                    return (double) array[0];
+                    return array[0];
                 }
                 throw new NumberFormatException("There are more than one component");
             }
             if (value instanceof int[]) {
                 int[] array = (int[]) value;
                 if (array.length == 1) {
-                    return (double) array[0];
+                    return array[0];
                 }
                 throw new NumberFormatException("There are more than one component");
             }
@@ -1083,6 +1083,7 @@ public class ExifInterface {
     private int mThumbnailOffset;
     private int mThumbnailLength;
     private byte[] mThumbnailBytes;
+    private boolean mIsSupportedFile;
 
     // Pattern to check non zero timestamp
     private static final Pattern sNonZeroTimePattern = Pattern.compile(".*[1-9].*");
@@ -1472,9 +1473,11 @@ public class ExifInterface {
 
             // Process JPEG input stream
             getJpegAttributes(in);
+            mIsSupportedFile = true;
         } catch (IOException e) {
             // Ignore exceptions in order to keep the compatibility with the old versions of
             // ExifInterface.
+            mIsSupportedFile = false;
             Log.w(TAG, "Invalid image: ExifInterface got an unsupported image format file"
                     + "(ExifInterface supports JPEG and some RAW image formats only) "
                     + "or a corrupted JPEG file to ExifInterface.", e);
@@ -1553,9 +1556,9 @@ public class ExifInterface {
      * and make a single call rather than multiple calls for each attribute.
      */
     public void saveAttributes() throws IOException {
-        if (mIsRaw) {
+        if (!mIsSupportedFile || mIsRaw) {
             throw new UnsupportedOperationException(
-                    "ExifInterface does not support saving attributes on RAW formats.");
+                    "ExifInterface only supports saving attributes on JPEG formats.");
         }
         if (mIsInputStream || (mSeekableFileDescriptor == null && mFilename == null)) {
             throw new UnsupportedOperationException(
@@ -2352,7 +2355,7 @@ public class ExifInterface {
         for (int i = 0; i < EXIF_TAGS.length; ++i) {
             int sum = 0;
             for (Map.Entry entry : (Set<Map.Entry>) mAttributes[i].entrySet()) {
-                final ExifAttribute exifAttribute = (ExifAttribute) ((Map.Entry) entry).getValue();
+                final ExifAttribute exifAttribute = (ExifAttribute) entry.getValue();
                 final int size = exifAttribute.size();
                 if (size > 4) {
                     sum += size;