Closes#22999
# Problem
Currently, the default soft wrap mode of an editor is determined by
reading the language-specific settings of the language _at offset zero_
in the editor's (multi)buffer. While this provides a way to pick a
single soft wrap mode for a multi-language multibuffer, it's a bad
choice for a single-buffer multibuffer that begins with a different
embedded language. For example, Markdown with frontmatter:
```markdown
---
my_front_matter
---
# Hello World
```
Setting this in config:
```json
"languages": {
"Markdown": { "soft_wrap": "bounded" }
},
```
Will not soft wrap the Markdown file as the language at offset zero is
YAML.
# Solution
Instead of using the language at offset zero, use the language of the
first buffer in the multibuffer (the buffer at offset zero). This gives
better behavior for single-buffer editors, and a similar default for
multi-language multibuffers as before.
# Testing
All existing `editor` crate tests pass, but I would appreciate any
guidance for where best to add additional testing.
Release Notes:
- Fixed soft_wrap setting not applying to buffers starting with a
different language
---------
Co-authored-by: Kirill Bulatov <kirill@zed.dev>