Add not zero check on tab-width.

[So1aric]

If set tab-width to zero, helix will crash (divided by zero). The error might occured from the helix-core/grapheme.rs.
Although it's a bit weird to set tab-width to zero (or even negative numbers), presenting the tab-width as 1 and alerting instead of panic would be better, IMO.

[Niketin]

Hi!

I am trying to get to a point where I could replicate the crash and debug the editor, but I am facing a problem. I am unable to change the tab-width. I am new to Helix, so I might do something wrong.

I configured tab-width to 2 in the ~/.config/helix/languages.toml.

[[language]]
name = "rust'
indent = { tab-width = 2, unit = "  " }

Then I reopened the editor (built in debug mode, if it matters), then I opened some Rust source file. The problem is that when I try to indent some selection using the < or >, it still uses 4 spaces. What am I doing wrong here?

[ravsii]

[[language]]
name = "rust'
indent = { tab-width = 2, unit = "  " }

@Niketin If this is your EXACT config, then your rust string is opened with a double quotation, but closed with a single one, making the config invalid

[Niketin]

I am sorry @ravsii, it is not the exact config because something weird happened to the text when I copy&pasted it from terminal.

The config should be this, with correct double quotations and without that weird brown highlighted text (if you can see it).

[[language]]
name = "rust"
indent = { tab-width = 2, unit = "  " }

[ravsii]

@Niketin I guess this is a rust-only issue, probably because of the cargo fmt whatever default formatter is used for rust, as it uses its own settings and probably should be changed inside the formatter option.

I'd suggest trying js,ts or some other web-related stuff. Working fine in svelte for example. (reproduced the crash as well)

[kirawi]

I am sorry @ravsii, it is not the exact config because something weird happened to the text when I copy&pasted it from terminal.

The config should be this, with correct double quotations and without that weird brown highlighted text (if you can see it).

[[language]]
name = "rust"
indent = { tab-width = 2, unit = "  " }

It's likely that your languages.toml isn't in the right place for Helix to pick it up.

[gabydd]

it might be picking it up and the auto-indentation detection is just overriding the setting cause the document uses spaces to indent, see src:

helix/helix-view/src/document.rs

Lines 888 to 891 in 9238054

	/// Detect the indentation used in the file, or otherwise defaults to the language indentation
	/// configured in `languages.toml`, with a fallback to tabs if it isn't specified. Line ending
	/// is likewise auto-detected, and will fallback to the default OS line ending.
	pub fn detect_indent_and_line_ending(&mut self) {

[apanloco]

you can reproduce this by:
echo "\t" > file.rs
then putting the above languages.toml configuration:

[[language]]
name = "rust"
indent = { tab-width = 0, unit = " " }

followed by
cargo run -- file.rs

 16:        0x103c1c408 - helix_core::graphemes::tab_width_at::hb5c054a65728acf8
                               at /Users/da/code/helix/helix-core/src/graphemes.rs:20:26

if the alerting is not important we could do a max(1, tab_width).

[apanloco]

we could nip it in the bud here in document.rs:

[gabydd]

The linked pr (#7178) makes it an error to have a non zero tab-width in your config which solves this issue without needing any custom logic

[Niketin]

I think it is in the right place, @kirawi. It's located in ~/.config/helix/languages.toml. I have the config file in the same directory and it works fine.

it might be picking it up and the auto-indentation detection is just overriding the setting cause the document uses spaces to indent, see src:

helix/helix-view/src/document.rs

Lines 888 to 891 in 9238054

	/// Detect the indentation used in the file, or otherwise defaults to the language indentation
	/// configured in `languages.toml`, with a fallback to tabs if it isn't specified. Line ending
	/// is likewise auto-detected, and will fallback to the default OS line ending.
	pub fn detect_indent_and_line_ending(&mut self) {

I believe @gabydd this is why I couldn't reproduce the problem.

you can reproduce this by: echo "\t" > file.rs then putting the above languages.toml configuration:

[[language]]
name = "rust"
indent = { tab-width = 0, unit = " " }

followed by cargo run -- file.rs

 16:        0x103c1c408 - helix_core::graphemes::tab_width_at::hb5c054a65728acf8
                               at /Users/da/code/helix/helix-core/src/graphemes.rs:20:26

@apanloco's instructions worked!