fix(diff): correctly relativize paths for diffing current buffer (#108)

lua/jj/annotate.lua

@@ -29,7 +29,7 @@ local function get_annotate_target()
 		return nil, nil, "Invalid jj:// buffer name"
 	end
 
-	local normalized, err = utils.normalize_repo_path(filename)
+	local normalized, err = utils.normalize_relative_path(filename)
 	if not normalized then
 		return nil, nil, err or "Could not normalize file path"
 	end

lua/jj/diff/diffview.lua

@@ -56,7 +56,7 @@ diff.register_backend("diffview", {
 		end
 
 		local raw_path = opts.path or jj_path or "%"
-		local path, err = utils.normalize_repo_path(raw_path)
+		local path, err = utils.normalize_relative_path(raw_path)
 		if not path then
 			utils.notify(err or "Could not resolve file path for Diffview", vim.log.levels.ERROR)
 			return

lua/jj/diff/native.lua

@@ -21,7 +21,7 @@ local function open_revision(rev, path)
 	end
 	local change_id = ids[1]
 
-	local rel_path, err = utils.normalize_repo_path(path)
+	local rel_path, err = utils.normalize_relative_path(path)
 	if not rel_path then
 		utils.notify(err or "Could not resolve path", vim.log.levels.ERROR)
 		return

lua/jj/file.lua

@@ -18,7 +18,7 @@ local parser = require("jj.core.parser")
 --- Fetch file content from jj synchronously.
 --- Returns lines with blank lines preserved; trailing empty line removed.
 --- @param rev string The revision (change ID or other revset)
---- @param path string Repository-relative path
+--- @param path string Cwd-relative path
 --- @return string[] lines
 --- @return boolean had_eol Whether the content had a trailing newline
 --- @return boolean ok Whether the command succeeded
@@ -46,7 +46,7 @@ M.get_file_content = get_file_content
 function M.read_target(opts)
 	local revision = opts and opts.rev or "@"
 	local raw_path = opts and opts.path or "%"
-	local path, normalize_err = utils.normalize_repo_path(raw_path)
+	local path, normalize_err = utils.normalize_relative_path(raw_path)
 	if not path then
 		utils.notify(normalize_err or "Could not normalize path", vim.log.levels.ERROR)
 		return
@@ -127,7 +127,7 @@ M.write_revision_file = write_revision_file
 function M.open_target(opts)
 	local revision = opts.rev or "@"
 	local raw_path = opts.path or "%"
-	local path, normalize_err = utils.normalize_repo_path(raw_path)
+	local path, normalize_err = utils.normalize_relative_path(raw_path)
 	if not path then
 		utils.notify(normalize_err or "Could not normalize path", vim.log.levels.ERROR)
 		return

lua/jj/utils.lua

@@ -161,18 +161,17 @@ function M.parse_jj_uri(name)
 	return name:match("^jj://([^/]+)/(.+)$")
 end
 
---- Normalize a user-provided file path to a repository-relative path for jj commands.
+--- Normalize a user-provided file path to a cwd-relative path for jj commands.
 ---
 --- Rules:
 --- - `%` resolves to the current buffer absolute file path.
---- - Absolute paths are converted to repository-relative paths.
---- - Relative paths are kept relative.
+--- - Absolute paths are converted to cwd-relative paths.
+--- - Relative paths are kept relative (already cwd-relative).
 ---
 --- @param path string|nil Path provided by the user (`%`, absolute, or relative)
---- @param root? string Repository root (defaults to current jj repo root)
---- @return string|nil normalized_path Repository-relative normalized path
+--- @return string|nil normalized_path Cwd-relative normalized path
 --- @return string|nil err Error message when normalization fails
-function M.normalize_repo_path(path, root)
+function M.normalize_relative_path(path)
 	path = vim.trim(path or "")
 	if path == "" then
 		return nil, "Path is empty"
@@ -191,18 +190,16 @@ function M.normalize_repo_path(path, root)
 
 	path = vim.fs.normalize(path)
 
-	root = root or M.get_jj_root()
-	if not root or root == "" then
-		return nil, "Not in a jj repository"
-	end
-
-	root = vim.fs.normalize(root)
-
 	local is_absolute = vim.startswith(path, "/") or path:match("^%a:/") ~= nil
 	if is_absolute then
-		local rel = M.relpath(root, path)
+		local cwd = vim.uv.cwd()
+		if not cwd or cwd == "" then
+			return nil, "Could not determine current working directory"
+		end
+		cwd = vim.fs.normalize(cwd)
+		local rel = M.relpath(cwd, path)
 		if not rel then
-			return nil, "Path is outside repository root"
+			return nil, "Path is outside current working directory"
 		end
 		path = rel
 	end
@@ -685,6 +682,7 @@ function M.get_describe_text(revset)
 
 	return text
 end
+
 ---
 --- Get the commit id from a given revision. Returns nil and notifies an error if multiple commit_ids are found for a single revset
 --- @param revset string The revset to extract the commit id from