Add kludge to improve handling of clicks after line wrapping breaks

Issue codemirror#4078

Author: marijnh

lib/codemirror.js

@@ -2933,10 +2933,23 @@
     for (;;) {
       if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
         var ch = x < fromX || x - fromX <= toX - x ? from : to;
+        var outside = ch == from ? fromOutside : toOutside
         var xDiff = x - (ch == from ? fromX : toX);
+        // This is a kludge to handle the case where the coordinates
+        // are after a line-wrapped line. We should replace it with a
+        // more general handling of cursor positions around line
+        // breaks. (Issue #4078)
+        if (toOutside && !bidi && !/\s/.test(lineObj.text.charAt(ch)) && xDiff > 0 &&
+            ch < lineObj.text.length && preparedMeasure.view.measure.heights.length > 1) {
+          var charSize = measureCharPrepared(cm, preparedMeasure, ch, "right");
+          if (innerOff <= charSize.bottom && innerOff >= charSize.top && Math.abs(x - charSize.right) < xDiff) {
+            outside = false
+            ch++
+            xDiff = x - charSize.right
+          }
+        }
         while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
-        var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
-                              xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
+        var pos = PosWithInfo(lineNo, ch, outside, xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
         return pos;
       }
       var step = Math.ceil(dist / 2), middle = from + step;