[jclsn]

📌 Summary

When diagnostics arrive for an unloaded buffer, its line count is 1, so the start line of every diagnostic was clamped to the first line while the end line was kept. Once the buffer was loaded, the inline highlight spanned from line 1 to the end of the diagnostic. Load the buffer before reading its line count.

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🔍 Related Issues

None

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🧪 What This PR Improves

Fixes a bug that sporadically happened for me in clangd.

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🛠️ Changes Made

Loading the buffer before reading its line count. There was already a Todo there.

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🧪 Testing

Repro:

repro.c

#include "repro.h"

int func1() { return 0; }
int func2() { return 0; }
int func3() { return 0; }
int func4() { return 0; }
int func5() { return 0; }

int main(void)
{
    f();
    return 0;
}

repro.h

#ifndef REPRO_H
#define REPRO_H

int f(void);

#endif

Steps:

1. Execute vim repro.c and wait for clangd to load
2. :e repro.h and remove the semicolon at the end of the function declaration to make clangd show and error. Save with :w.
3. :b repro.c
4. The whole file should be highlighted as error.

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📦 Breaking Changes

Does this PR introduce any breaking changes?

• Yes
• No

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📚 Documentation

Does this PR require documentation updates?

• Yes
• No

If yes, describe what needs updating.

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✔️ Checklist

• I have tested this with a minimal Vim9script configuration.
• I have run the plugin against the relevant LSP server(s).
• I have updated documentation if needed.
• I have followed the project’s coding style and conventions.
• I have added tests or examples where appropriate.