vscode.executeDocumentSymbolProvider seems to only work once (or at least only once in close succession)

[eamodio]

Environment data

• VS Code version: 1.25 or 1.26
• Extension version (available under the Extensions sidebar): 2018.6.0
• OS and version: Windows 10 x64
• Python version (& distribution if applicable, e.g. Anaconda): Python 2.7.15
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): N/A

Originally reported here: https://github.com/DonJayamanne/pythonVSCode/issues/553
Another case of this here: gitkraken/vscode-gitlens#439

Actual behavior

Executing vscode.executeDocumentSymbolProvider only returns all the symbols on the first call, successive calls return 0 symbols (at least within a small window)

Expected behavior

Executing vscode.executeDocumentSymbolProvider should return all the symbols no matter how many times (concurrently or not) it is called

Steps to reproduce:

1. Call vscode.executeDocumentSymbolProvider more than once in close succession (or observe the behavior seen in GitLens breaks Outline for Python gitkraken/vscode-gitlens#439)

[ericsnowcurrently]

Also related: gitkraken/vscode-gitlens#18.

[ericsnowcurrently]

Hi @eamodio! Thanks for letting us know about this. Sorry about the delay and how DonJayamanne#553 slipped through the cracks when we moved the issues over to this repo.

I've taken a stab at reproducing the issue, following the steps in gitkraken/vscode-gitlens#439:

1. use the default settings in the Python extension
2. install the GitLens extension
3. open the outline view
4. open a simple Python file (and check the outline)
5. open another Python file (and check the outline)

Doing this I didn't have any problems (the outline filled out properly for each file). I also did not have any problems when I used the new language server. It could be that the results differ based on the contents of the file. We'd need examples of such files in order to proceed. Could you provide any?

FYI, there's a known issue with the language server that we're handling separately.

[ericsnowcurrently]

(from @rjbruin Aug 1, 2018, 5:39 AM MDT)

@ericsnowcurrently Thanks!

It seems the issue is connected to the new language server:

• No GitLens + "python.jediEnabled": true: works;
• No GitLens + "python.jediEnabled": false: no file outline will load anymore, and switching out of Explorer and back doesn't return the outline anymore

However, even when disabling the new language server and enabling GitLens the issue remains. Even more confusing, I'm not seeing the same behavior anymore even with the settings of the original issue:

• GitLens + "python.jediEnabled": true (original issue): certain files load without problem, while others don't. Things I've tried to narrow down the differences:
  • Both files are in a repository tracked by GitLens: the one that breaks outline is in our main company repository, the one that works is in a new local repository;
  • Both files have the exact same content and name;
  • Both workspace folders use the same Python interpreter (from virtualenv)

I'm getting kind of lost here. As for the GitLens issue, it seems to have to do with the repository the file is in. If I can do anything to help debug this, please let me know!

[ericsnowcurrently]

@rjbruin, from the GitLens issue I noticed you are using VSCode 1.24.1. I've been trying to reproduce the problem using 1.25.1 (with no failures). Try upgrading VSCode and then see if the failure persists. Also, what version of the Python extension are you on right now? I'm using 2018.7.1 (the latest release). Thanks!

@DonJayamanne, any thoughts on this?