Adjust hint.fromList to consistenly use the cursor as end pos

Issue codemirror#5312

Author: marijnh

addon/hint/show-hint.js

@@ -397,13 +397,13 @@
   });
 
   CodeMirror.registerHelper("hint", "fromList", function(cm, options) {
-    var cur = cm.getCursor(), token = cm.getTokenAt(cur);
-    var to = CodeMirror.Pos(cur.line, token.end);
-    if (token.string && /\w/.test(token.string[token.string.length - 1])) {
-      var length = token.string.length - (token.end - cur.ch);
-      var term = token.string.substr(0, length), from = CodeMirror.Pos(cur.line, token.start);
+    var cur = cm.getCursor(), token = cm.getTokenAt(cur)
+    var term, from = CodeMirror.Pos(cur.line, token.start), to = cur
+    if (token.start < cur.ch && /\w/.test(token.string.charAt(cur.ch - token.start - 1))) {
+      term = token.string.substr(0, cur.ch - token.start)
     } else {
-      var term = "", from = to;
+      term = ""
+      from = cur
     }
     var found = [];
     for (var i = 0; i < options.words.length; i++) {