From b752a8696a984d3d45a6ad321395b214ce5f1030 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <zauguin@gmail.com>
Date: Fri, 10 Jul 2020 21:57:43 +0200
Subject: [PATCH] Simpler luametatex.lua

Use kpsewhich instead of trying to find init script manually
---
 luametalatex.lua | 100 +++++------------------------------------------
 1 file changed, 10 insertions(+), 90 deletions(-)

diff --git a/luametalatex.lua b/luametalatex.lua
index 2985d5d..baae1ee 100644
--- a/luametalatex.lua
+++ b/luametalatex.lua
@@ -1,109 +1,29 @@
--- Some helpers based on Penlight
-local absdir, dirsep
-do
-  local sep = package.config:sub(1,1)
-  local is_windows = sep == "\\"
-  dirsep = lpeg.S(is_windows and '\\/' or '/')
-  local anchor_pattern = lpeg.Cs(is_windows
-    and lpeg.P'\\\\' + dirsep/'\\' + 1*lpeg.P':'*dirsep^-1/'\\'
-    or  lpeg.P'//' + dirsep^1/'/')
-  function isabs(P)
-    return P:sub(1,1) == '/' or (is_windows and (P:sub(1,1)=='\\' or P:sub(2,2)==':'))
-  end
-  local insert, remove, concat = table.insert, table.remove, table.concat
-  function normpath(P)
-    -- Split path into anchor and relative path.
-    local anchor, P = ((anchor_pattern + lpeg.Cc'') * lpeg.C(lpeg.P(1)^0)):match(P)
-    if is_windows then
-      P = P:gsub('/','\\')
-    end
-    local parts = {}
-    for part in P:gmatch('[^'..sep..']+') do
-      if part == '..' then
-        if #parts ~= 0 and parts[#parts] ~= '..' then
-          remove(parts)
-        else
-          insert(parts, part)
-        end
-      elseif part ~= '.' then
-        insert(parts, part)
-      end
-    end
-    P = anchor..concat(parts, sep)
-    if P == '' then P = '.' end
-    return P
-  end
-  function join(p1,p2,...)
-    if select('#',...) > 0 then
-      local p = join(p1,p2)
-      return join(p, ...)
-    end
-    if isabs(p2) then return p2 end
-    local endc = p1:sub(#p1,#p1)
-    if endc ~= "/" and (not is_windows or endc ~= "\\") and endc ~= "" then
-      p1 = p1..sep
-    end
-    return p1..p2
-  end
-  function absdir(P,pwd)
-    local use_pwd = pwd ~= nil
-    pwd = pwd or lfs.currentdir()
-    if not isabs(P) then
-      P = join(pwd,P)
-    elseif is_windows and not use_pwd and P:sub(2,2) ~= ':' and P:sub(2,2) ~= '\\' then
-      P = pwd:sub(1,2)..P -- attach current drive to path like '\\fred.txt'
-    end
-    return normpath(P) .. sep
-  end
-end
--- Who are we anyway?
 local format = os.selfname -- or os.selfcore, I couldn't find a difference yet
 local ourname = arg[0] -- This might not be os.selfarg[0]
+-- We want to drop arg[0] aka. ourname from the arguments to avoid recursion
 if os.selfarg[0] == ourname then
   ourname = nil
 end
 for i, a in ipairs(os.selfarg) do
-  -- LuaMetaTeX needs -- to introduce parameters,
-  -- but fmtutil uses just -. Let's rewrite this on the fly:
   if a == ourname then -- Avoid recursion
     table.remove(os.selfarg, i)
     ourname = nil
     a = os.selfarg[i]
   end
-  if a == "--" then break end
+  if a == "--" then break end -- This convention is not respected by luametatex itself
+  -- LuaMetaTeX needs -- to introduce parameters,
+  -- but fmtutil uses just -. Let's rewrite this on the fly:
   a = a:gsub("^%-%-?", "--")
   os.selfarg[i] = a
   if a:sub(1, 11) == "--progname=" then
     format = a:sub(12)
   end
 end
-local dir = absdir(os.selfdir)
-local dirseparators = {((lpeg.S'\\/'^1 + 1 * lpeg.P':' * lpeg.S'\\/'^-1) * lpeg.Cp() * ((1-lpeg.S'\\/')^0*lpeg.S'\\/'*lpeg.Cp())^0):match(dir)}
--- First step: Find our actual format.
-local init_script = format .. "-init.lua"
-local texmf_dir = "tex/" .. format .. "/base/" .. init_script
-local paths = {
-  init_script,
-  "share/texmf-local/" .. texmf_dir,
-  "share/texmf-dist/" .. texmf_dir,
-  "share/texmf/" .. texmf_dir,
-  "texmf-local/" .. texmf_dir,
-  "texmf-dist/" .. texmf_dir,
-  "texmf/" .. texmf_dir,
-}
-for i = #dirseparators, 1, -1 do
-  dir = dir:sub(1, dirseparators[i] - 1)
-  for _, subdir in ipairs(paths) do
-    local full_path = dir .. subdir
-    local attr = lfs.attributes(full_path)
-    if attr then
-      dir = full_path
-      goto FOUND
-    end
-  end
-end
-error[[CRITICAL: Initialization script not found]]
-::FOUND::
 os.setenv("engine", status.luatex_engine)
+local kpse_call = io.popen(string.format("kpsewhich -progname %s -format lua -must-exist %s-init.lua", format, format))
+local file = kpse_call:read()
+if not kpse_call:close() then
+  error(file)
+end
 local args = os.selfarg[1] and " \"" .. table.concat(os.selfarg, "\" \"") .. "\"" or ""
-os.exit(os.execute(string.format("luametatex \"--lua=%s\" --arg0=\"%s\"%s", dir, os.selfarg[0], args)))
+os.exit(os.execute(string.format("luametatex \"--lua=%s\" --arg0=\"%s\"%s", file, os.selfarg[0], args)))