This justifies my stance of "find the most normal setup and use it".
This is a bug in the less popular third-party lsp package for emacs, which is already quite unpopular.
I use VSCode, an enormously complex system. But so many other people use it there tends not to be this sort of bug. And in the rare case there is one I just wait a few days until someone else solves it.
In this particular case, Vscode doesn't have the bug... Because it's responsible for this mess in the first place. LSP was first introduced in Vscode which is written in C++ and typescript, so they found it convenient to assume a UTF-16 encoding (as is native to Javascript). If LSP had originated elsewhere it'd probably use codepoint or UTF-8 byte offsets from the start.
Exactly. On a moral level that's obviously bad. But on a practical level that supports my decision to use VSCode - they got to define the standard such that everyone else has to work around their mess, making themselves have less problems.
This is a bug in the less popular third-party lsp package for emacs, which is already quite unpopular.
I use VSCode, an enormously complex system. But so many other people use it there tends not to be this sort of bug. And in the rare case there is one I just wait a few days until someone else solves it.