From 1808edc1f07c3b65588124f805312466fb743d39 Mon Sep 17 00:00:00 2001
From: Lazar Bulovan <lazar.bulovan@l-tech.biz>
Date: Thu, 19 Feb 2026 11:56:09 +0100
Subject: [PATCH] fix(lsp): validate line numbers in semantic tokens and inlay
 hints

The error 'Invalid line: out of range' was caused by semantic tokens
and inlay hints using variable line numbers that might be out of bounds
for the current document content. This could happen when the cached
variables from a previous document version have line numbers that don't
match the current content.

Added validation to both textDocument_semanticTokensFull and
textDocument_inlayHint to ensure line numbers are within the valid
range (0 to total_lines - 1) before processing.
---
 src/main.lua | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/main.lua b/src/main.lua
index 2467e78..f689aa9 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -568,8 +568,14 @@ function handlers.textDocument_semanticTokensFull(params)
 	for line in doc.content:gmatch("([^\n]*)\n") do
 		table.insert(lines, line)
 	end
+	
+	local total_lines = #lines
 
 	local function add_token(line, startChar, length, tokenType)
+		-- Validate line number is within bounds
+		if line < 0 or line >= total_lines then
+			return
+		end
 		local deltaLine = line
 		local deltaStart = startChar
 		if #tokens >= 4 then
@@ -595,7 +601,8 @@ function handlers.textDocument_semanticTokensFull(params)
 
 		if doc.variables then
 			for var_name, info in pairs(doc.variables) do
-				if info.line == lineNum then
+				-- Validate variable line number is within bounds
+				if info.line and info.line >= 0 and info.line < total_lines and info.line == lineNum then
 					local startChar = line:find(var_name, 1, true)
 					if startChar then
 						add_token(lineNum, startChar - 1, #var_name, "variable")
@@ -673,11 +680,14 @@ function handlers.textDocument_inlayHint(params)
 		table.insert(lines, line)
 	end
 
+	local total_lines = #lines
+
 	for i, line in ipairs(lines) do
 		local lineNum = i - 1
 		if doc.variables then
 			for var_name, info in pairs(doc.variables) do
-				if info.line == lineNum and info.data_type and info.data_type ~= "unknown" then
+				-- Validate line number is within bounds
+				if info.line and info.line >= 0 and info.line < total_lines and info.line == lineNum and info.data_type and info.data_type ~= "unknown" then
 					local colonPos = line:find(":", 1, true)
 					if colonPos then
 						table.insert(hints, {