Update maxLine when adding or clearing a collapsed range

Closes #1161

Author: marijnh

lib/codemirror.js

@@ -1967,7 +1967,7 @@ window.CodeMirror = (function() {
     if (!cm.options.lineWrapping) {
       checkWidthStart = lineNo(visualLine(doc, firstLine));
       doc.iter(checkWidthStart, to.line + 1, function(line) {
-        if (lineLength(doc, line) == view.maxLineLength) {
+        if (line == view.maxLine) {
           recomputeMaxLength = true;
           return true;
         }
@@ -3288,7 +3288,7 @@ window.CodeMirror = (function() {
   TextMarker.prototype.clear = function() {
     if (this.explicitlyCleared) return;
     startOperation(this.cm);
-    var min = null, max = null;
+    var view = this.cm.view, min = null, max = null;
     for (var i = 0; i < this.lines.length; ++i) {
       var line = this.lines[i];
       var span = getMarkedSpanFor(line.markedSpans, this);
@@ -3299,6 +3299,15 @@ window.CodeMirror = (function() {
       else if (this.collapsed && !lineIsHidden(line))
         updateLineHeight(line, textHeight(this.cm.display));
     }
+    if (this.collapsed && !this.cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
+      var visual = visualLine(view.doc, this.lines[i]), len = lineLength(view.doc, visual);
+      if (len > view.maxLineLength) {
+        view.maxLine = visual;
+        view.maxLineLength = len;
+        view.maxLineChanged = true;
+      }
+    }
+
     if (min != null) regChange(this.cm, min, max + 1);
     this.lines.length = 0;
     this.explicitlyCleared = true;
@@ -3351,6 +3360,8 @@ window.CodeMirror = (function() {
 
     var curLine = from.line, size = 0, collapsedAtStart, collapsedAtEnd;
     doc.iter(curLine, to.line + 1, function(line) {
+      if (marker.collapsed && !cm.options.lineWrapping && visualLine(doc, line) == cm.view.maxLine)
+        cm.curOp.updateMaxLine = true;
       var span = {from: null, to: null, marker: marker};
       size += line.text.length;
       if (curLine == from.line) {span.from = from.ch; size -= from.ch;}