8278805: Enhance BMP image loading

Reviewed-by: andrew
Backport-of: 6319119be51e595be82f253b9f5e9495e72d4ad9

src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageReader.java

diff --git a/src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageReader.java b/src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageReader.java
index 3aaf73c..bff23de 100644
--- a/src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageReader.java
+++ b/src/java.desktop/share/classes/com/sun/imageio/plugins/bmp/BMPImageReader.java
@@ -69,8 +69,9 @@
 import java.util.List;
 import java.util.StringTokenizer;
 
-import com.sun.imageio.plugins.common.ImageUtil;
 import com.sun.imageio.plugins.common.I18N;
+import com.sun.imageio.plugins.common.ImageUtil;
+import com.sun.imageio.plugins.common.ReaderUtil;
 
 /** This class is the Java Image IO plugin reader for BMP images.
  *  It may subsample the image, clip the image, select sub-bands,
@@ -1536,9 +1537,8 @@
         }
 
         // Read till we have the whole image
-        byte values[] = new byte[imSize];
-        int bytesRead = 0;
-        iis.readFully(values, 0, imSize);
+        byte[] values = ReaderUtil.
+            staggeredReadByteStream(iis, imSize);
 
         // Since data is compressed, decompress it
         decodeRLE8(imSize, padding, values, bdata);
@@ -1720,8 +1720,8 @@
         }
 
         // Read till we have the whole image
-        byte[] values = new byte[imSize];
-        iis.readFully(values, 0, imSize);
+        byte[] values = ReaderUtil.
+            staggeredReadByteStream(iis, imSize);
 
         // Decompress the RLE4 compressed data.
         decodeRLE4(imSize, padding, values, bdata);