Fixed NullPointerException cases on snapshot images parsing.

htroot/api/snapshot.java

@@ -304,6 +304,10 @@ public class snapshot {
                 Image image;
                 try {
                     image = ImageParser.parse(imageFile.getAbsolutePath(), FileUtils.read(imageFile));
+                    if(image == null) {
+                    	/* Should not happen. If so, ImageParser.parse() should already have logged about the error */
+                    	return null;
+                    }
                     final Image scaled = image.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING);
                     final MediaTracker mediaTracker = new MediaTracker(new Container());
                     mediaTracker.addImage(scaled, 0);

source/net/yacy/cora/util/Html2Image.java

@@ -199,7 +199,11 @@ public class Html2Image {
             try {
                 File newPngFile = new File(pngFile.getAbsolutePath() + ".png");
                 pngFile.renameTo(newPngFile);
-                Image img = ImageParser.parse(pngFile.getAbsolutePath(), FileUtils.read(newPngFile));
+                final Image img = ImageParser.parse(pngFile.getAbsolutePath(), FileUtils.read(newPngFile));
+                if(img == null) {
+                	/* Should not happen. If so, ImageParser.parse() should already have logged about the error */
+                	return false;
+                }
                 final Image scaled = img.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING);
                 final MediaTracker mediaTracker = new MediaTracker(new Container());
                 mediaTracker.addImage(scaled, 0);