Fix some crashes

app/src/main/java/app/fedilab/android/helper/RecyclerViewThreadLines.kt

@@ -32,7 +32,7 @@ class RecyclerViewThreadLines(context: Context, private val lineInfoList: List<L
     private val margin: Int = baseMargin * fontScale
 
     override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
-        val position = (view.layoutParams as RecyclerView.LayoutParams).viewLayoutPosition
+        val position = parent.getChildAdapterPosition(view)
         val level = lineInfoList[position].level
         val startMargin = margin * level + margin * fontScale
         if (parent.layoutDirection == View.LAYOUT_DIRECTION_LTR) outRect.left = startMargin else outRect.right = startMargin

app/src/main/java/app/fedilab/android/helper/SpannableHelper.java

@@ -187,7 +187,7 @@ public class SpannableHelper {
             if (matchEnd > content.toString().length()) {
                 matchEnd = content.toString().length();
             }
-            if (content.toString().length() < matchEnd || matchStart < 0) {
+            if (content.toString().length() < matchEnd || matchStart < 0 || matchStart > matchEnd) {
                 continue;
             }
             final String url = content.toString().substring(matchStart, matchEnd);