False Positive: Source file is not valid UTF-8

[DaanDeMeyer]

I sometimes get a 'source file is not valid UTF-8' error when editing C++ code with cquery. Haven't been able to find out how to reproduce it.

Commenting/uncommenting line doesn't remove the error. Removing and pasting all the code in the file does remove the error

[topisani]

I get this too, but only in vsc, never in emacs

[DaanDeMeyer]

I think I've reproduced it.

It happens whenever I type in a character such as 'à' or 'é' by accident.

[jacobdufault]

What happens if you compile the file using clang after having typed the character? Does it complain?

[DaanDeMeyer]

Clang compiles without warnings or errors

[agauniyal]

depends on which version is being used to compile, it could be clang 5 since this plugin is using 4.

[topisani]

its definately a bug, it compiles fine, and as mentioned, only happens in the vscode client.

[MaskRay]

Fixed?

[jhasse]

Fixed?

Still happens for me when using umlauts in literals for example.

[MaskRay]

Example source file?

[Riatre]

I can confirm that this still happens. How to reproduce:

1. Open a source file with VSCode client.
2. Type in some non-ASCII character (in my case, "（", though anything non single byte should work).
3. cquery reports "source file is not valid UTF-8", which is unexpected, but reasonable.
4. Delete that character, cquery still reports "source file is not valid UTF-8", which is unexpected. Reload the entire VSCode fixes this.

My guess is it might be a bug in vscode client.

[topisani]

My guess is it might be a bug in vscode client.

nope, happens in emacs too - but often it works for me to just delete the line i entered a bad char on and paste it back (saving for reindex in between)

[Riatre]

Seems like this is caused by the fact that all the offsets and lengths in Language Server Protocol is given as the amount of UTF-8 characters UTF-16 code units instead of bytes, and we treat it as bytes when updating WorkingFile.buffer_content. (src/working_files.cc:333)

Sounds difficult to fix without introducing UTF-16 aware std::string indexing codes.

Edit: Nope, it's not UTF-8, it's UTF-16 as per specification. But TextDocumentContentChangeEvent.text is sent in UTF-8. (╯‵□′)╯︵┻━┻

[Riatre]

And what's worse, lsp-mode have no idea about these UTF-16 things, so positions coming from Emacs would be in UTF-8 characters.

Maybe we could use an UTF-8 iterator of std::string for working on buffer_content, this still breaks whenever there are 4-byte UTF-8 characters (as at this point Visual Studio Code disagrees with lsp-mode on how many "characters" there are). But being unable to insert emoji should be less annoying than having to restart cquery after accidentally typed in à or （.

[MaskRay]

Thank @Riatre for troubleshooting. Emacs lsp-mode is good now. Don't use emojis 😿 in VSCode