Uncaught TypeError: Cannot read property 'text' of undefined

[mMerlin]

This seems to be related to another atom reported problem when using tab splitting. The split seems to work, but after closing a split, various operation on same file in the 'main' tab start failing. At a high level, it looks to me like some of the structures / pointers for the file in another tab were deleted when the split was closed.

Remembered sequence: Slit a tab to get same file in 2 views; do stuff; save changes (operation very slow); close tab; do stuff; save; fail

Stack trace:
TypeError: Cannot read property 'text' of undefined
at DisplayBuffer.module.exports.DisplayBuffer.buildScreenLines (/opt/atom/share/atom/resources/app/src/display-buffer.js:1510:70)
at DisplayBuffer.module.exports.DisplayBuffer.updateScreenLines (/opt/atom/share/atom/resources/app/src/display-buffer.js:1464:20)
at DisplayBuffer.module.exports.DisplayBuffer.handleTokenizedBufferChange (/opt/atom/share/atom/resources/app/src/display-buffer.js:1444:12)
at /opt/atom/share/atom/resources/app/src/display-buffer.js:5:61
at Emitter.module.exports.Emitter.emit (/opt/atom/share/atom/resources/app/node_modules/event-kit/lib/emitter.js:82:11)
at TokenizedBuffer.module.exports.TokenizedBuffer.handleBufferChange (/opt/atom/share/atom/resources/app/src/tokenized-buffer.js:355:27)
at /opt/atom/share/atom/resources/app/src/tokenized-buffer.js:56:24
at Emitter.module.exports.Emitter.emit (/opt/atom/share/atom/resources/app/node_modules/service-hub/node_modules/event-kit/lib/emitter.js:82:11)
at TextBuffer.module.exports.TextBuffer.applyPatch (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/text-buffer.js:594:20)
at BufferPatch.module.exports.BufferPatch.applyTo (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/buffer-patch.js:74:21)
at Transaction.module.exports.Transaction.applyTo (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/transaction.js:60:29)
at History.module.exports.History.abortTransaction (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/history.js:165:24)
at History.module.exports.History.transact (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/history.js:122:16)
at TextBuffer.module.exports.TextBuffer.transact (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/text-buffer.js:687:27)
at TabsToSpaces.module.exports.TabsToSpaces.replaceWhitespaceWithSpaces (/home/phil/.atom/packages/tabs-to-spaces/lib/tabs-to-spaces.coffee:50:12)
at TabsToSpaces.module.exports.TabsToSpaces.untabify (/home/phil/.atom/packages/tabs-to-spaces/lib/tabs-to-spaces.coffee:19:6)
at /home/phil/.atom/packages/tabs-to-spaces/lib/index.coffee:39:24
at Emitter.module.exports.Emitter.emit (/opt/atom/share/atom/resources/app/node_modules/service-hub/node_modules/event-kit/lib/emitter.js:82:11)
at TextBuffer.module.exports.TextBuffer.saveAs (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/text-buffer.js:965:20)
at TextBuffer.module.exports.TextBuffer.save (/opt/atom/share/atom/resources/app/node_modules/text-buffer/lib/text-buffer.js:958:19)
at TextEditor.module.exports.TextEditor.save (/opt/atom/share/atom/resources/app/src/text-editor.js:620:26)
at Pane.module.exports.Pane.saveItem (/opt/atom/share/atom/resources/app/src/pane.js:538:16)
at Pane.module.exports.Pane.saveActiveItem (/opt/atom/share/atom/resources/app/src/pane.js:522:19)
at Workspace.module.exports.Workspace.saveActivePaneItemAndReportErrors (/opt/atom/share/atom/resources/app/src/workspace.js:689:44)
at Workspace.module.exports.Workspace.saveActivePaneItem (/opt/atom/share/atom/resources/app/src/workspace.js:679:19)
at atom-workspace.atom.commands.add.core:save (/opt/atom/share/atom/resources/app/src/workspace-element.js:295:30)
at CommandRegistry.module.exports.CommandRegistry.handleCommandEvent (/opt/atom/share/atom/resources/app/src/command-registry.js:243:29)
at /opt/atom/share/atom/resources/app/src/command-registry.js:3:61
at KeymapManager.module.exports.KeymapManager.dispatchCommandEvent (/opt/atom/share/atom/resources/app/node_modules/atom-keymap/lib/keymap-manager.js:558:16)
at KeymapManager.module.exports.KeymapManager.handleKeyboardEvent (/opt/atom/share/atom/resources/app/node_modules/atom-keymap/lib/keymap-manager.js:396:22)
at HTMLDocument.module.exports.WindowEventHandler.onKeydown (/opt/atom/share/atom/resources/app/src/window-event-handler.js:170:20)

[lee-dohm]

Could you give the following information?

• Which version of Atom are you using?
• What OS and version are you running?
• Do you have the Shadow DOM feature enabled?
• Do you have the Emmet package installed?
• Can you reproduce the issue after completely exiting Atom and restarting using atom --safe?

Thanks for reporting!

[mMerlin]

Atom Version 0.177.0-5dea6e7
Fedora 21, kernel 3.18.7-200.fc21.i686 running as a guest VM in VirtualBox on Windows 7
Shadow DOM is enabled
No Emmet package
Settings >> Packages >> Installed Packages shows 71 Core packages, plus only tabs-to-spaces in Community Packages.

I am quite new to using atom. The setup should be fairly generic. I have added a (very) few settings tweaks from recommendations based on just what I have been doing. Working with html, css, javascript, markdown.

Can not reproduce on the simple described sequence. Since the fail occurred in a much longer editing session, likely something else is interacting. For now, I am making it a habit to close and reopen the file after closing the split.

[lee-dohm]

Can you update to the latest version of Atom and let me know if this still reproduces?

[mMerlin]

Pulled the latest repo commits.
Updated to 0.183.0-25befa7. I'll report back if/when I get the error again.

How often do I need to update to 'latest' for your reporting? Given how often commits are going in, I could be 10 behind in the time it takes to do the rebuild, and post this message.

[lee-dohm]

The latest release version (in this case, v0.182.0) is generally just fine. I suspect that this issue was caused by using the latest version of tabs-to-spaces on versions of Atom prior to v0.179.0, which was released over a week ago. Also, I'm probably going to give less priority to issues with unreleased versions that don't reproduce on released versions.

[mMerlin]

backed up to version 0.182.0-d1e6dba and rebuilt. No problems with split / unsplit in preliminary testing. Since the original was built only a couple weeks ago, I had no idea it could be that far out of date. 5 'release' versions.

[lee-dohm]

Has this been resolved?

[mMerlin]

I have not seen a repeat since upgrading the atom version. Looks like it.

However, I have had to turn off the automatic untabify on save. With the size the project file has grown to, saving got too slow. At least when doing quick change and test cycles for the javascript.

[lee-dohm]

Thanks for the update! And #16 covers the performance issue. I don't really want to diverge from using Atom's built-in scan functions, so I'll just have to push for general perf increases in Atom itself to resolve that one.

[mMerlin]

The speed comment was more to note that the reported problem is no longer being tested much in my environment. With tabs-to-spaces only being run 'on request', the scenario that caused the problem is not being hit any longer.

And yes, atom itself needs some performance improvements. I just reported a simple case: select all with most of the content folded.