As reported [in
Discord](https://discord.com/channels/869392257814519848/1106226198494859355/1398470747227426948)
C projects with `"` as "brackets" that autoclose, may invoke panics when
edited at the end of the file.
With a single selection-caret (`ˇ`), at the end of the file,
```c
ifndef BAR_H
#define BAR_H
#include <stdbool.h>
int fn_branch(bool do_branch1, bool do_branch2);
#endif // BAR_H
#include"ˇ"
```
gets an LSP response from clangd
```jsonc
{
"filterText": "AGL/",
"insertText": "AGL/",
"insertTextFormat": 1,
"kind": 17,
"label": " AGL/",
"labelDetails": {},
"score": 0.78725427389144897,
"sortText": "40b67681AGL/",
"textEdit": {
"newText": "AGL/",
"range": { "end": { "character": 11, "line": 8 }, "start": { "character": 10, "line": 8 } }
}
}
```
which replaces `"` after the caret (character/column 11, 0-indexed).
This is reasonable, as regular follow-up (proposed in further
completions), is a suffix + a closing `"`:
<img width="842" height="259" alt="image"
src="https://github.com/user-attachments/assets/ea56f621-7008-4ce2-99ba-87344ddf33d2"
/>
Yet when Zed handles user input of `"`, it panics due to multiple
reasons:
* after applying any snippet text edit, Zed did a selection change:
5537987630/crates/editor/src/editor.rs (L9539-L9545)
which caused eventual autoclose region invalidation:
5537987630/crates/editor/src/editor.rs (L2970)
This covers all cases that insert the `include""` text.
* after applying any user input and "plain" text edit, Zed did not
invalidate any autoclose regions at all, relying on the "bracket" (which
includes `"`) autoclose logic to rule edge cases out
* bracket autoclose logic detects previous `"` and considers the new
user input as a valid closure, hence no autoclose region needed.
But there is an autoclose bracket data after the plaintext completion
insertion (`AGL/`) really, and it's not invalidated after `"` handling
* in addition to that, `Anchor::is_valid` method in `text` panicked, and
required `fn try_fragment_id_for_anchor` to handle "pointing at odd,
after the end of the file, offset" cases as `false`
A test reproducing the feedback and 2 fixes added: proper, autoclose
region invalidation call which required the invalidation logic tweaked a
bit, and "superficial", "do not apply bad selections that cause panics"
fix in the editor to be more robust
Release Notes:
- Fixed panic with completion ranges and autoclose regions interop
---------
Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
6a8be1714e