Unable to display a label from KML if the label also has a custom style on an icon...

[lowzonenose]

When you write a kml with a label that has 2 styles,
one for the text, and the other for the custom icon,
the 'name' tag is not written to the output kml.
So, when you want to import it to a map, the label
can not be displayed...

You can see the problem :
https://jsfiddle.net/lowzonenose/c9qqbkLz/

We can resolve it if we modify the code into the class ol.format.KML :

ol.format.KML.writePlacemark_ = function(node, feature, objectStack) {
  (...)
  var styleFunction = feature.getStyleFunction();
  if (styleFunction) {
    // FIXME the styles returned by the style function are supposed to be
    // resolution-independent here
    var styles = styleFunction.call(feature, 0);
    if (styles) {
      var style = Array.isArray(styles) ? styles[0] : styles;
      if (this.writeStyles_) {
        properties['Style'] = style;
      }
      // Unnecessary if this property is already filled !
      // So it's not necessary to overwrite it...
      if (!properties.hasOwnProperty("name")) {  // --> the fix is here !  <--
        var textStyle = style.getText();
        if (textStyle) {
          properties['name'] = textStyle.getText();
        }
      }
    }
  }
 (...)
}

[lowzonenose]

This little patch does not solve everything,
the ideal would be to have a function to merge styles...
If there are several styles, they are merged to return only one style...