Uncaught TypeError: Cannot read property 'length' of null

[yongkangchen]

Uncaught TypeError: Cannot read property 'length' of null /Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/history.js:100

mac os x: 10.9.4
atom: 0.125.0

Also, I try to debug and print the error stack:

TypeError
 "TypeError: Cannot read property 'length' of null
  at Marker.module.exports.Marker.resumeChangeEvents (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/marker.js:558:47)
  at MarkerManager.module.exports.MarkerManager.resumeChangeEvents (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/marker-manager.js:235:30)
  at TextBuffer.module.exports.TextBuffer.applyPatch (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:448:15)
  at TextBuffer.module.exports.TextBuffer.setTextInRange (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:322:12)
  at Editor.module.exports.Editor.setIndentationForBufferRow (/Applications/Atom.app/Contents/Resources/app/src/editor.js:1033:26)
  at LanguageMode.module.exports.LanguageMode.autoDecreaseIndentForBufferRow (/Applications/Atom.app/Contents/Resources/app/src/language-mode.js:394:28)
  at Editor._results.push._this.(anonymous function) [as autoDecreaseIndentForBufferRow] (/Applications/Atom.app/Contents/Resources/app/node_modules/delegato/lib/delegator.js:67:61)
  at Selection.module.exports.Selection.insertText (/Applications/Atom.app/Contents/Resources/app/src/selection.js:478:21)
  at /Applications/Atom.app/Contents/Resources/app/src/editor.js:807:31
  at /Applications/Atom.app/Contents/Resources/app/src/editor.js:502:27
  at History.module.exports.History.transact (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/history.js:90:18)
  at TextBuffer.module.exports.TextBuffer.transact (/Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/text-buffer.js:1020:27)
  at Editor.module.exports.Editor.transact (/Applications/Atom.app/Contents/Resources/app/src/editor.js:1104:26)
  at Editor.module.exports.Editor.mutateSelectedText (/Applications/Atom.app/Contents/Resources/app/src/editor.js:495:19)
  at Editor.module.exports.Editor.insertText (/Applications/Atom.app/Contents/Resources/app/src/editor.js:804:21)
  at Editor.object.(anonymous function) [as insertText] (/Applications/Atom.app/Contents/Resources/app/node_modules/underscore-plus/lib/underscore-plus.js:55:27)
  at [object Object].module.exports.React.createClass.onTextInput (/Applications/Atom.app/Contents/Resources/app/src/editor-component.js:870:18)
  at HTMLDivElement.boundMethod (/Applications/Atom.app/Contents/Resources/app/node_modules/react-atom-fork/lib/ReactCompositeComponent.js:1295:21)

This is how to reproduce the bug:

[izuzak]

@yongkangchen Can you reproduce this in safe mode?

[yongkangchen]

safe mode is normal. I guess this cause by autocomplete-plus, and I create the same issue.

[izuzak]

Thanks for confirming. I'm going to close this issue, but please reopen it in https://github.com/atom/atom if you notice it in safe mode.

Also, I'm going to cc @nathansobo and @benogle on this -- that stack trace above is interesting, it doesn't seem to include anything related to autocomplete-plus, so I'm wondering if there indeed is something we could do to prevent these exceptions.

[izuzak]

Reopening, see 94115e2#commitcomment-7727788

[zenizh]

Exactly the same problem here on OS X 10.9.4 and Atom 0.125.0.
And I also use autocomplete-plus.
Just for reference.

[yongkangchen]

@kami30k I temporary edit the file /Applications/Atom.app/Contents/Resources/app/node_modules/text-buffer/lib/marker.js and modify function resumeChangeEvents to avoid the annoying bug, and you can try it until they fix this.

    Marker.prototype.resumeChangeEvents = function() {
      var deferredChangeEvents, event, _i, _len, _results;
      deferredChangeEvents = this.deferredChangeEvents;
      this.deferredChangeEvents = null;
      _results = [];

      if(deferredChangeEvents){
        for (_i = 0, _len = deferredChangeEvents.length; _i < _len; _i++) {
          event = deferredChangeEvents[_i];
          this.emit('changed', event);
          _results.push(this.emitter.emit('did-change', event));
        }
      }
      return _results;
    };

[nathansobo]

This must be happening when something is inserting a marker within a buffer change event callback. Certainly a valid use case but it wasn't exercised by any of our code. This should be fixed on the next release, which we will expedite. Thanks for your patience.