Treat SVGs as document attachments.

app/src/main/java/org/thoughtcrime/securesms/MediaPreviewActivity.java

@@ -73,6 +73,7 @@ import org.thoughtcrime.securesms.sharing.ShareActivity;
 import org.thoughtcrime.securesms.util.AttachmentUtil;
 import org.thoughtcrime.securesms.util.DateUtils;
 import org.thoughtcrime.securesms.util.FullscreenHelper;
+import org.thoughtcrime.securesms.util.MediaUtil;
 import org.thoughtcrime.securesms.util.SaveAttachmentTask;
 import org.thoughtcrime.securesms.util.SaveAttachmentTask.Attachment;
 import org.thoughtcrime.securesms.util.StorageUtil;
@@ -534,7 +535,7 @@ public final class MediaPreviewActivity extends PassphraseRequiredActivity
   }
 
   public static boolean isContentTypeSupported(final String contentType) {
-    return contentType != null && (contentType.startsWith("image/") || contentType.startsWith("video/"));
+    return MediaUtil.isImageType(contentType) || MediaUtil.isVideoType(contentType);
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/util/MediaUtil.java

@@ -293,7 +293,7 @@ public class MediaUtil {
       return false;
     }
 
-    return contentType.startsWith("image/") ||
+    return (contentType.startsWith("image/") && !contentType.equals("image/svg+xml")) ||
            contentType.equals(MediaStore.Images.Media.CONTENT_TYPE);
   }
 

app/src/main/java/org/thoughtcrime/securesms/util/MemoryFileDescriptorProxy.java

@@ -71,6 +71,10 @@ final class MemoryFileDescriptorProxy {
       try {
         InputStream inputStream = memoryFile.getInputStream();
         if(inputStream.skip(offset) != offset){
+          if (offset > memoryFile.length()) {
+            throw new ErrnoException("onRead", OsConstants.EIO);
+          }
+
           throw new AssertionError();
         }
         return inputStream.read(data, 0, size);