RFR: 8335216: [windows] Missing error check for GetSystemDirectory in glass

[Kevin Rushforth]

On Mon, 8 Jul 2024 14:24:27 GMT, Lukasz Kostyra <lkostyra at openjdk.org> wrote:

> When GetSystemDirectory does not have enough space to output a path to Windows' system directory, it will return a different value than 0 (more notably, the amount of bytes actually needed including null terminator). This was not checked, so the very rare hypothetical situation where Windows' system directory is different than the "standard" `C:\Windows` and longer than MAX_PATH was not properly handled.
> 
> For now I simply changed the code to print an error and exit. This could be improved further to instead dynamically allocate space for the system directory though.
> 
> Other changes, also mentioned in the issue:
> - We use `wchar_t` explicitly here, so I changed `GetSystemDirectory` to `GetSystemDirectoryW` to ensure the code compiles even without UNICODE being defined
> - `wcscat_s` can potentially fail for the same reasons as above, so this situation is also handled now.

I'll review this.

@mstr2 Would you like to be the second reviewer?

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PR Comment: https://git.openjdk.org/jfx/pull/1498#issuecomment-2214830534