Add RequestUninstallerExecutionLevel

[justanotheranonymoususer]

I tried to implement RequestUninstallerExecutionLevel, see https://sourceforge.net/p/nsis/feature-requests/560/

It's a small change, but helps me get rid of a large hack. Please accept this change to help me avoid maintaining a fork, and to help others who need this small feature.

[sredna]

This does not actually work.

[justanotheranonymoususer]

Maybe now? Added the enum value

[sredna]

Maybe now?

Have you actually verified that this works? I would expect changes to build.cpp.

[justanotheranonymoususer]

Frankly, no, haven't had the time to set up a dev environment. But it looks simple enough, and I'll happily test the resulting pre-release binaries.

I would expect changes to build.cpp.

Why?

[sredna]

Why?

Because the uninstaller is generated from the installer. Your code changes probably have zero effect.

[kichik]

There is only one manifest_exec_level. Being in uninstall_mode doesn't make it point somewhere else. If you want a different manifest, you would have to edit it as the uninstaller is being written. That happens when the installer runs, not in compile time.

nsis/Source/exehead/exec.c

Line 1554 in de09827

case EW_WRITEUNINSTALLER:

[justanotheranonymoususer]

So I read a bit more of the code. As far as I understand, the uninstaller is created by the installer as a delta of its own, which is something I didn't realize before. I thought of a solution, and I think what can be done is changing the code here:
https://github.com/kichik/nsis/blob/HEAD/Source/manifest.cpp#L177-L190
so that all options will take the same amount of bytes (pad with spaces). Then, it can be changed by the installer at runtime. But I can see how it's not easy as I thought.

I might get back to it later. Now, I have two options that I see: use the old hack, or change the uninstaller code to elevate at startup, without a manifest. The "elevate at startup" option has pros: less disk space in the installer, less hacks in the code, and cons: the process is being launched twice, Windows doesn't show shield icon.