Fix the range of sections in document symbols (#846)

[kylebutts]

This solution fixes #846 and posit-dev/positron#6137.

The problem comes from here:

ark/crates/ark/src/lsp/symbols.rs

Lines 231 to 271 in fac7824

	fn index_comments(
	node: &Node,
	mut store_stack: StoreStack,
	contents: &Rope,
	) -> anyhow::Result<StoreStack> {
	let comment_text = contents.node_slice(&node)?.to_string();
	// Check if the comment starts with one or more '#' followed by any text and ends with 4+ punctuations
	let Some((level, title)) = parse_comment_as_section(&comment_text) else {
	return Ok(store_stack);
	};
	// Create a section symbol based on the parsed comment
	let start = convert_point_to_position(contents, node.start_position());
	let end = convert_point_to_position(contents, node.end_position());
	let symbol = new_symbol(title, SymbolKind::STRING, Range { start, end });
	// Now pop all sections still on the stack that have a higher or equal
	// level. Because we pop sections with equal levels, i.e. siblings, we
	// ensure that there is only one active section per level on the stack.
	// That simplifies things because we need to assign popped sections to their
	// parents and we can assume the relevant parent is always the next on the
	// stack.
	loop {
	let Some((last_level, _, _)) = store_stack.last() else {
	return Err(anyhow!("Unexpectedly reached the end of the store stack"));
	};
	if *last_level >= level {
	if store_stack_pop(&mut store_stack)?.is_some() {
	return Err(anyhow!("Unexpectedly reached the end of the store stack"));
	}
	continue;
	}
	break;
	}
	store_stack.push((level, Some(symbol), vec![]));
	Ok(store_stack)
	}

• node is the single comment line, so the "section" is defined as the single line.

The solution I settled on was to take the created nested symbols and then "correct" the the end positions of the sections

• I did this to avoid a O(n^2) loop where you loop through the lines to find section starts and then loop through the lines again to find where the next header starts.

This also fixes the sticky scroll which was also breaking from the sections having "1-line height"

[lionel-]

Thanks @kylebutts! I went with a different approach in #855

[kylebutts]

Great! The new logic looks a lot nicer :->