Command line command to install wont install if newer version already installed

[hilleer]

• VSCode Version: 1.18.1
• OS Version: macOS High Sierra 10.13.1

Steps to Reproduce:

1. Have two identical vsix files of an extension, but with different version tags. I made two test ones here: (https://github.com/hilleer/vscode-install-cli-test-vsixs)[https://github.com/hilleer/vscode-install-cli-test-vsixs]
2. Install the latest (version 1.1.0 from the example ones`) from within vscode or from the command line.
3. Reload / check that the extension is installed (1.1.0)
4. Install the old version (version 1.0.0 from the example ones) from the command line (`code --install-extension ).
5. Reload vscode, and check the version of the extension - still the version of the first (newest) installed version.

Reproduces without extensions: Yes/No

[sandy081]

We generally do not support installing outdated extensions from gallery. But I think it makes sense to support it for vsix installations.

If you are trying to install an older versions using vsix, now, we show a confirmation asking to override the newer version with older version.

[sandy081]

@joaomoreno As part of this fix, I had to flip the order of extensions clean up. Now, I remove first obsolete extensions and then remove outdated extensions 4fb98ff. Want to know if the previous order had any reason?

[joaomoreno]

No reason! 👍

[hilleer]

Thanks for implementing this! 👍

[ramya-rao-a]

@sandy081 Verified that this works after confirming the override.
But when I press 1 for Cancel, there is a callstack printed out

[sandy081]

Good catch @ramya-rao-a

Fixed.