Don't show console on Windows

[sheremetyev]

When used inside GUI application, git2 causes console window to appear temporarily, due to execution of sh.

Command needs special flags to prevent that. More details: https://stackoverflow.com/a/60958956

(For context - similar change in gitoxide: GitoxideLabs/gitoxide#1506)

[ehuss]

@ChrisDenton does this make sense to you? Essentially, when configuring a credential helper on Windows, the git2 library executes it (first trying with sh). It sounds like in a GUI application this is popping open a console window. Is this the right way to suppress that?

[ChrisDenton]

Sure.

The only downside of CREATE_NO_WINDOW I can think of is that it may be slightly slower to execute in some circumstances because it needs to create a new console session (albeit not a shell or a window) even if one already exists. However, I doubt that will have a measurable impact. Using DETACHED_PROCESS would fix that except if the child process itself spawns child processes then you may get a console window again.

Another option would be to merely hide any new window. But the Rust API is nightly only and on older versions of Windows it may still show a flash of the console window before it's hidden.

tl;dr CREATE_NO_WINDOW is probably the best option currently. An alternative would be to give library users some measure of control over process spawning. But that's more complicated and perhaps unnecessary.

[ehuss]

OK, thanks! I'll go ahead and merge, and if we have any issues, we can revisit.

[ehuss]

Thanks!