Adding test lineWidgetIssue5486 for #5486

Author: laobubu

test/test.js

@@ -1658,6 +1658,56 @@ testCM("lineWidgetChanged", function(cm) {
   eq(info0.top + expectedWidgetHeight, info2.top);
 });
 
+testCM("lineWidgetIssue5486", function(cm) {
+  // [prepare]
+  // 2nd line is combined to 1st line due to markText
+  // 2nd line has a lineWidget below
+
+  cm.setValue("Lorem\nIpsue\nDollar")
+
+  var el = document.createElement('div')
+  el.style.height='50px'
+  el.textContent = '[[LINE WIDGET]]'
+  
+  var lineWidget = cm.addLineWidget(1, el, {
+    above: false,
+    coverGutter: false,
+    noHScroll: false,
+    showIfHidden: false,
+  })
+  
+  var marker = document.createElement('span')
+  marker.textContent = '[--]'
+  
+  cm.markText({line:0, ch: 1}, {line:1, ch: 4}, {
+    replacedWith: marker
+  })
+
+  // before resizing the lineWidget, measure 3rd line position
+
+  var measure_1 = Math.round(cm.charCoords({line:2, ch:0}).top)
+  
+  // resize lineWidget, height + 50 px
+
+  el.style.height='100px'
+  el.textContent += "\nlineWidget size changed.\nTry moving cursor to line 3?"
+  
+  lineWidget.changed()
+
+  // re-measure 3rd line position
+  var measure_2 = Math.round(cm.charCoords({line:2, ch:0}).top)
+  eq(measure_2, measure_1 + 50)
+
+  // (extra test)
+  //
+  // add char to the right of the folded marker
+  // and re-measure 3rd line position
+
+  cm.replaceRange('-', {line:1, ch: 5})
+  var measure_3 = Math.round(cm.charCoords({line:2, ch:0}).top)
+  eq(measure_3, measure_2)
+});
+
 testCM("getLineNumber", function(cm) {
   addDoc(cm, 2, 20);
   var h1 = cm.getLineHandle(1);