data loss with new C++ text buffer backend under some cirumstances

[despairblue]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Reproduced the problem in Safe Mode: http://flight-manual.atom.io/hacking-atom/sections/debugging/#using-safe-mode
  • Followed all applicable steps in the debugging guide: http://flight-manual.atom.io/hacking-atom/sections/debugging/
  • Checked the FAQs on the message board for common solutions: https://discuss.atom.io/c/faq
  • Checked that your issue isn't already filed: https://github.com/issues?utf8=✓&q=is%3Aissue+user%3Aatom
  • Checked that there is not already an Atom package that provides the described functionality: https://atom.io/packages

Description

Since Atom 1.19 enabling this plugin can lead to data loss.

Steps to Reproduce

1. Enable autosave.
2. Open a file.
3. Enter test enter.
4. Save.
5. Remove new line.
6. Hit cmd-w.

Expected behavior: [What you expect to happen]

File should either be saved or atom should ask if you want to save the changes to the file.

Actual behavior: [What actually happens]

Empty file is saved.

Reproduces how often: [What percentage of the time does it reproduce?]

Evertime for removing new lines, happens in conjunction with prettier-atom in all cases where prettier changes the file. See: prettier/prettier-atom#264

Versions

• Atom: 1.19.7
• Atom-Shell:
• OS: Mac OS X 10.12.6
• Misc
  • apm 1.18.4
  • npm 3.10.10
  • node 6.9.5 x64
  • python 2.7.10
  • git 2.11.0

Additional Information

[despairblue]

Disabling the whitespace package prevents this from happening. So I guess this happens whenever a package changes the buffer onWillSave.

Yep, just checked, also happens when using editorconfig instead of whitespace.

[despairblue]

@Ben3eeE I'm happy to help reproduce this, I tested this with atom --safe and whitespace and autosave plugins enabled. It always saved an empty file when removing the trailing new line or adding a trailing whitespace to a line.

[maxbrunsfeld]

Wow thanks for the report and I apologize for this very serious regression. I'll be working on this today.

[despairblue]

Thanks for working on this, luckily I lost nothing major, just refactoring grunt work 😄

[maxbrunsfeld]

~@despairblue I haven't been able to reproduce this yet; at the final step, when I type cmd-w, I am prompted to save the file as expected. If instead of using cmd-w I focus another window, Atom saves the correct contents of the file.~~

Does this happen if you run atom in safe mode?

[maxbrunsfeld]

Oh, nevermind. I had the Ensure Single Trailing Newline option turned off. With that option enabled, I can reproduce this using your steps. Fixing now.

[maxbrunsfeld]

@despairblue This data loss bug is fixed on Atom's master branch. There is still a bug that when autosave is turned on, you get a save prompt when closing a tab with cmd-w. I am looking into that one next.

[despairblue]

@maxbrunsfeld Thank you ❤️