more error handling for avatar publication

src/eu/siacs/conversations/persistance/FileBackend.java

@@ -285,6 +285,9 @@ public class FileBackend {
 		try {
 			Avatar avatar = new Avatar();
 			Bitmap bm = cropCenterSquare(image, size);
+			if (bm==null) {
+				return null;
+			}
 			ByteArrayOutputStream mByteArrayOutputStream = new ByteArrayOutputStream();
 			Base64OutputStream mBase64OutputSttream = new Base64OutputStream(mByteArrayOutputStream, Base64.DEFAULT);
 			MessageDigest digest = MessageDigest.getInstance("SHA-1");
@@ -355,7 +358,11 @@ public class FileBackend {
 			InputStream is = context.getContentResolver()
 					.openInputStream(image);
 			Bitmap input = BitmapFactory.decodeStream(is, null, options);
-			return cropCenterSquare(input, size);
+			if (input==null) {
+				return null;
+			} else {
+				return cropCenterSquare(input, size);
+			}
 		} catch (FileNotFoundException e) {
 			return null;
 		}

src/eu/siacs/conversations/ui/PublishProfilePictureActivity.java

@@ -129,6 +129,9 @@ public class PublishProfilePictureActivity extends XmppActivity {
 		if (resultCode == RESULT_OK) {
 			if (requestCode == REQUEST_CHOOSE_FILE) {
 				this.avatarUri = data.getData();
+				if (xmppConnectionServiceBound) {
+					loadImageIntoPreview(this.avatarUri);
+				}
 			}
 		}
 	}
@@ -173,6 +176,12 @@ public class PublishProfilePictureActivity extends XmppActivity {
 	protected void loadImageIntoPreview(Uri uri) {
 		Bitmap bm = xmppConnectionService.getFileBackend().cropCenterSquare(
 				uri, 384);
+		if (bm==null) {
+			disablePublishButton();
+			this.hintOrWarning.setTextColor(getWarningTextColor());
+			this.hintOrWarning.setText(R.string.error_publish_avatar_converting);
+			return;
+		}
 		this.avatar.setImageBitmap(bm);
 		if (support) {
 			enablePublishButton();