opt: findtext casesensitivity (#1698)

* opt: reset the selection results

* opt: remove the existed highlight when no match

* [autofix.ci] apply automated fixes

* opt: remove the existed highlight when no match

* opt: remove the existed highlight when no match

* opt: code minor optimization

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/ui/articleview.cc

@@ -2026,8 +2026,13 @@ void ArticleView::performFindOperation( bool backwards )
     f |= QWebEnginePage::FindBackward;
 
   findText( text, f, [ text, this ]( bool match ) {
-    bool setMark = !text.isEmpty() && !match;
-    Utils::Widget::setNoResultColor( searchPanel->lineEdit, setMark );
+    bool nomatch = !text.isEmpty() && !match;
+    if ( nomatch ) {
+      //clear the previous findText results.
+      //when the results is empty, the highlight has not been removed.more likely a qt bug.
+      webview->findText( "" );
+    }
+    Utils::Widget::setNoResultColor( searchPanel->lineEdit, nomatch );
   } );
 }
 
@@ -2065,10 +2070,7 @@ bool ArticleView::closeSearch()
     ftsSearchPanel->hide();
     webview->setFocus();
 
-    QWebEnginePage::FindFlags flags( 0 );
-
-    webview->findText( "", flags );
-
+    webview->findText( "" );
     return true;
   }
   return false;