Geth dumpconfig in Windows PowerShell with Incompatible File Encoding

[msagansk]

System information

Geth version: 1.8.2-stable-b8b9f7f4
OS & Version: Windows 10

Expected behaviour

Should be able to dumpconfig in PowerShell and immediately run geth after with that config file.

Actual behaviour

PS C:\Ethereum> geth --datadir "C:\Ethereum" --lightserv 25 --identity Mearix dumpconfig > config.toml
INFO [03-22|20:25:11] Maximum peer count ETH=25 LES=100 total=125
PS C:\Ethereum> geth --config config.toml
Fatal: config.toml, line 1: invalid TOML syntax
PS C:\Ethereum>

Reason

PowerShell defaults to outputting text files in UCS-2 LE BOM. If I change the encoding of the file to ANSI or UTF-8 geth works fine. But from a user experience point of view, geth should be able to read many different text file encoding formats out of the box.

[holiman]

Possible fix, add dumpconfig conf.toml and have geth write to the file, or dumpconfig - to write to stdout

[karalabe]

Fixed by #18327. dumpconfig now accepts an optional filename parameter into which to dump the config on platforms where piping is problematic.