fix(textbox): multiline paste didn't move the selection to the end of…

… the paste text

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBox.cs

@@ -1130,7 +1130,19 @@ internal string ProcessTextInput(string newText)
 			try
 			{
 				_isInputModifyingText = true;
+				var oldText = Text;
 				Text = newText;
+
+#if __SKIA__
+				if (_pendingSelection is { } selection && Text == oldText)
+				{
+					// OnTextChanged won't fire, so we immediately change the selection.
+					// Note how we check that Text (after assignment) == oldText and
+					// not oldText == newText. This is because CoerceText can make it so that
+					// newText != oldText but Text (after assignment) == oldText
+					SelectInternal(selection.start, selection.length);
+				}
+#endif
 			}
 			finally
 			{

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBox.skia.cs

@@ -508,20 +508,10 @@ partial void OnKeyDownPartial(KeyRoutedEventArgs args)
 		var caretXOffset = _caretXOffset;
 
 		_suppressCurrentlyTyping = true;
-		if (text == Text)
-		{
-			if (!_isPressed)
-			{
-				SelectInternal(selectionStart, selectionLength);
-			}
-		}
-		else
-		{
-			_clearHistoryOnTextChanged = false;
-			_pendingSelection = (selectionStart, selectionLength);
-			ProcessTextInput(text);
-			_clearHistoryOnTextChanged = true;
-		}
+		_clearHistoryOnTextChanged = false;
+		_pendingSelection = (selectionStart, selectionLength);
+		ProcessTextInput(text);
+		_clearHistoryOnTextChanged = true;
 		_suppressCurrentlyTyping = false;
 
 		// don't change the caret offset when moving up and down
@@ -1254,15 +1244,7 @@ partial void PasteFromClipboardPartial(string clipboardText, int selectionStart,
 				CommitAction(new ReplaceAction(Text, newText, selectionStart));
 			}
 
-			if (Text == newText)
-			{
-				// OnTextChanged won't fire, so we immediately change the selection
-				Select(selectionStart + clipboardText.Length, 0);
-			}
-			else
-			{
-				_pendingSelection = (selectionStart + clipboardText.Length, 0);
-			}
+			_pendingSelection = (selectionStart + clipboardText.Length, 0);
 		}
 	}