Merge pull request #30 from phi-gamma/master

implement feature request #24

8 files changed, 656 insertions, 3 deletions

diff --git a/luaotfload-auxiliary.lua b/luaotfload-auxiliary.lua
new file mode 100644
index 0000000..2cf1e00
--- /dev/null
+++ b/luaotfload-auxiliary.lua
@@ -0,0 +1,406 @@
+#!/usr/bin/env texlua
+-----------------------------------------------------------------------
+--         FILE:  luaotfload-auxiliary.lua
+--  DESCRIPTION:  part of luaotfload
+-- REQUIREMENTS:  luaotfload 2.2
+--       AUTHOR:  Khaled Hosny, Élie Roux, Philipp Gesang
+--      VERSION:  1.0
+--      CREATED:  2013-05-01 14:40:50+0200
+-----------------------------------------------------------------------
+--
+
+--- this file addresses issue #24
+--- https://github.com/lualatex/luaotfload/issues/24#
+
+luaotfload                  = luaotfload or {}
+luaotfload.aux              = luaotfload.aux or { }
+
+config                      = config or { }
+config.luaotfload           = config.luaotfload or { }
+
+local aux           = luaotfload.aux
+local log           = luaotfload.log
+local identifiers   = fonts.hashes.identifiers
+
+local fontid        = font.id
+local texsprint     = tex.sprint
+
+local utf8          = unicode.utf8
+local stringlower   = string.lower
+local stringformat  = string.format
+local stringgsub    = string.gsub
+local stringbyte    = string.byte
+
+-----------------------------------------------------------------------
+---                          font patches
+-----------------------------------------------------------------------
+
+--[[doc--
+This sets two dimensions apparently relied upon by the unicode-math
+package.
+--doc]]--
+
+local set_sscale_dimens = function (fontdata)
+  local mathconstants = fontdata.MathConstants
+  local parameters    = fontdata.parameters
+  if mathconstants then
+    parameters[10] = mathconstants.ScriptPercentScaleDown or 70
+    parameters[11] = mathconstants.ScriptScriptPercentScaleDown or 50
+  end
+  return fontdata
+end
+
+luatexbase.add_to_callback(
+  "luaotfload.patch_font",
+  set_sscale_dimens,
+  "luaotfload.aux.set_sscale_dimens")
+
+--- fontobj -> int
+local lookup_units = function (fontdata)
+  local metadata = fontdata.shared and fontdata.shared.rawdata.metadata
+  if metadata and metadata.units_per_em then
+    return metadata.units_per_em
+  elseif fontdata.parameters and fontdata.parameters.units then
+    return fontdata.parameters.units
+  elseif fontdata.units then --- v1.x
+    return fontdata.units
+  end
+  return 1000
+end
+
+--[[doc--
+This callback corrects some values of the Cambria font.
+--doc]]--
+local patch_cambria_domh = function (fontdata)
+  local mathconstants = fontdata.MathConstants
+  if mathconstants and fontdata.psname == "CambriaMath" then
+    --- my test Cambria has 2048
+    local units_per_em = fontdata.units_per_em or lookup_units(fontdata)
+    local sz           = fontdata.parameters.size or fontdata.size
+    local mh           = 2800 / units_per_em * sz
+    if mathconstants.DisplayOperatorMinHeight < mh then
+      mathconstants.DisplayOperatorMinHeight = mh
+    end
+  end
+end
+
+luatexbase.add_to_callback(
+  "luaotfload.patch_font",
+  patch_cambria_domh,
+  "luaotfload.aux.patch_cambria_domh")
+
+--[[doc--
+
+Comment from fontspec:
+
+ “Here we patch fonts tfm table to emulate \XeTeX's \cs{fontdimen8},
+  which stores the caps-height of the font. (Cf.\ \cs{fontdimen5} which
+  stores the x-height.)
+
+  Falls back to measuring the glyph if the font doesn't contain the
+  necessary information.
+  This needs to be extended for fonts that don't contain an `X'.”
+
+--doc]]--
+
+local set_capheight = function (fontdata)
+    local shared     = fontdata.shared
+    local parameters = fontdata.parameters
+    local capheight
+    if shared then
+      local units_per_em   = parameters.units
+      local size           = parameters.size
+      local os2_capheight  = shared.rawdata.metadata.pfminfo.os2_capheight
+
+      if os2_capheight > 0 then
+        capheight = os2_capheight / units_per_em * size
+      else
+        local X8 = stringbyte"X"
+        if fontdata.characters[X8] then
+          capheight = fontdata.characters[X8].height
+        else
+          capheight = parameters.ascender / units_per_em * size
+        end
+      end
+    else
+      local X8 = stringbyte"X"
+      if fontdata.characters[X8] then
+        capheight = fontdata.characters[X8].height
+      end
+    end
+    if capheight then
+      --- is this legit? afaics there’s nothing else on the
+      --- array part of that table
+      fontdata.parameters[8] = capheight
+    end
+end
+
+luatexbase.add_to_callback(
+  "luaotfload.patch_font",
+  set_capheight,
+  "luaotfload.aux.set_capheight")
+
+-----------------------------------------------------------------------
+---                             glyphs
+-----------------------------------------------------------------------
+
+--- int -> int -> bool
+local font_has_glyph = function (font_id, codepoint)
+  local fontdata = fonts.hashes.identifiers[font_id]
+  if fontdata then
+    if fontdata.characters[codepoint] ~= nil then return true end
+  end
+  return false
+end
+
+aux.font_has_glyph = font_has_glyph
+
+--- int -> bool
+local current_font_has_glyph = function (codepoint)
+  return font_has_glyph (font.current(), codepoint)
+end
+
+aux.current_font_has_glyph = current_font_has_glyph
+
+local do_if_glyph_else = function (chr, positive, negative)
+  local codepoint = tonumber(chr)
+  if not codepoint then codepoint = utf8.byte(chr) end
+  if current_font_has_glyph(codepoint) then
+    tex.sprint(positive)
+  else
+    tex.sprint(negative)
+  end
+end
+
+aux.do_if_glyph_else = do_if_glyph_else
+
+--[[doc--
+
+  This one is approximately “name_to_slot” from the microtype package;
+  note that it is all about Adobe Glyph names and glyph slots in the
+  font. The names and values may diverge from actual Unicode.
+
+  http://www.adobe.com/devnet/opentype/archives/glyph.html
+
+--doc]]--
+
+--- string -> (int | false)
+local slot_of_name = function (glyphname)
+  local fontdata = identifiers[font.current()]
+  if fontdata then
+    local unicode = fontdata.resources.unicodes[glyphname]
+    if unicode and type(unicode) == "number" then
+      return unicode
+    else
+      return unicode[1] --- for multiple components
+    end
+  end
+  return false
+end
+
+aux.slot_of_name = slot_of_name
+
+--[[doc--
+
+  Inverse of above; not authoritative as to my knowledge the official
+  inverse of the AGL is the AGLFN. Maybe this whole issue should be
+  dealt with in a separate package that loads char-def.lua and thereby
+  solves the problem for the next couple decades.
+
+  http://partners.adobe.com/public/developer/en/opentype/aglfn13.txt
+
+--doc]]--
+
+local indices
+
+--- int -> (string | false)
+local name_of_slot = function (codepoint)
+  if not indices then --- this will load the glyph list
+    local unicodes = fonts.encodings.agl.unicodes
+    indices = table.swapped(unicodes)
+  end
+  local glyphname = indices[codepoint]
+  if glyphname then
+    return glyphname
+  end
+  return false
+end
+
+aux.name_of_slot      = name_of_slot
+
+-----------------------------------------------------------------------
+---                 features / scripts / languages
+-----------------------------------------------------------------------
+--- lots of arrowcode ahead
+
+--[[doc--
+This function, modeled after “check_script()” from fontspec, returns
+true if in the given font, the script “asked_script” is accounted for in at
+least one feature.
+--doc]]--
+
+--- int -> string -> bool
+local provides_script = function (font_id, asked_script)
+  asked_script = stringlower(asked_script)
+  if font_id and font_id > 0 then
+    local fontdata = identifiers[font_id].shared.rawdata
+    if fontdata then
+      local fontname = fontdata.metadata.fontname
+      local features = fontdata.resources.features
+      for method, featuredata in next, features do
+        --- where method: "gpos" | "gsub"
+        for feature, data in next, featuredata do
+          if data[asked_script] then
+            log(stringformat(
+              "font no %d (%s) defines feature %s for script %s",
+              font_id, fontname, feature, asked_script))
+            return true
+          end
+        end
+      end
+      log(stringformat(
+        "font no %d (%s) defines no feature for script %s",
+        font_id, fontname, asked_script))
+    end
+  end
+  log(stringformat("no font with id %d", font_id))
+  return false
+end
+
+aux.provides_script = provides_script
+
+--[[doc--
+This function, modeled after “check_language()” from fontspec, returns
+true if in the given font, the language with tage “asked_language” is
+accounted for in the script with tag “asked_script” in at least one
+feature.
+--doc]]--
+
+--- int -> string -> string -> bool
+local provides_language = function (font_id, asked_script, asked_language)
+  asked_script     = stringlower(asked_script)
+  asked_language   = stringlower(asked_language)
+  if font_id and font_id > 0 then
+    local fontdata = identifiers[font_id].shared.rawdata
+    if fontdata then
+      local fontname = fontdata.metadata.fontname
+      local features = fontdata.resources.features
+      for method, featuredata in next, features do
+        --- where method: "gpos" | "gsub"
+        for feature, data in next, featuredata do
+          local scriptdata = data[asked_script]
+          if scriptdata and scriptdata[asked_language] then
+            log(stringformat("font no %d (%s) defines feature %s "
+                          .. "for script %s with language %s",
+                             font_id, fontname, feature,
+                             asked_script, asked_language))
+            return true
+          end
+        end
+      end
+      log(stringformat(
+        "font no %d (%s) defines no feature for script %s with language %s",
+        font_id, fontname, asked_script, asked_language))
+    end
+  end
+  log(stringformat("no font with id %d", font_id))
+  return false
+end
+
+aux.provides_language = provides_language
+
+--[[doc--
+We strip the syntax elements from feature definitions (shouldn’t
+actually be there in the first place, but who cares ...)
+--doc]]--
+
+local lpeg        = require"lpeg"
+local C, P, S     = lpeg.C, lpeg.P, lpeg.S
+local lpegmatch   = lpeg.match
+
+local sign            = S"+-"
+local rhs             = P"=" * P(1)^0 * P(-1)
+local strip_garbage   = sign^-1 * C((1 - rhs)^1)
+
+--s   = "+foo"        --> foo
+--ss  = "-bar"        --> bar
+--sss = "baz"         --> baz
+--t   = "foo=bar"     --> foo
+--tt  = "+bar=baz"    --> bar
+--ttt = "-baz=true"   --> baz
+--
+--print(lpeg.match(strip_garbage, s))
+--print(lpeg.match(strip_garbage, ss))
+--print(lpeg.match(strip_garbage, sss))
+--print(lpeg.match(strip_garbage, t))
+--print(lpeg.match(strip_garbage, tt))
+--print(lpeg.match(strip_garbage, ttt))
+
+--[[doc--
+This function, modeled after “check_feature()” from fontspec, returns
+true if in the given font, the language with tag “asked_language” is
+accounted for in the script with tag “asked_script” in feature
+“asked_feature”.
+--doc]]--
+
+--- int -> string -> string -> string -> bool
+local provides_feature = function (font_id,        asked_script,
+                                   asked_language, asked_feature)
+  asked_script    = stringlower(asked_script)
+  asked_language  = stringlower(asked_language)
+  asked_feature   = lpegmatch(strip_garbage, asked_feature)
+
+  if font_id and font_id > 0 then
+    local fontdata = identifiers[font_id].shared.rawdata
+    if fontdata then
+      local features = fontdata.resources.features
+      local fontname = fontdata.metadata.fontname
+      for method, featuredata in next, features do
+        --- where method: "gpos" | "gsub"
+        local feature = featuredata[asked_feature]
+        if feature then
+          local scriptdata = feature[asked_script]
+          if scriptdata and scriptdata[asked_language] then
+            log(stringformat("font no %d (%s) defines feature %s "
+                          .. "for script %s with language %s",
+                             font_id, fontname, asked_feature,
+                             asked_script, asked_language))
+            return true
+          end
+        end
+      end
+      log(stringformat(
+        "font no %d (%s) does not define feature %s for script %s with language %s",
+        font_id, fontname, asked_feature, asked_script, asked_language))
+    end
+  end
+  log(stringformat("no font with id %d", font_id))
+  return false
+end
+
+aux.provides_feature = provides_feature
+
+-----------------------------------------------------------------------
+---                         font dimensions
+-----------------------------------------------------------------------
+
+--- string -> string -> int
+local get_math_dimension = function (csname, dimenname)
+  local fontdata  = identifiers[fontid(csname)]
+  local mathdata  = fontdata.mathparameters
+  if mathdata then return mathdata[dimenname] or 0 end
+  return 0
+end
+
+aux.get_math_dimension = get_math_dimension
+
+--- string -> string -> unit
+local sprint_math_dimension = function (csname, dimenname)
+  local dim = get_math_dimension(csname, dimenname)
+  texsprint(luatexbase.catcodetables["latex-package"], dim)
+  texsprint(luatexbase.catcodetables["latex-package"], "sp")
+end
+
+aux.sprint_math_dimension = sprint_math_dimension
+
+-- vim:tw=71:sw=2:ts=2:expandtab
diff --git a/luaotfload.dtx b/luaotfload.dtx
index dd43990..fd71485 100644
--- a/luaotfload.dtx
+++ b/luaotfload.dtx
@@ -1226,6 +1226,11 @@ luaotfload.font_definer = "patch" --- | “generic” | “old”
 local error, warning, info, log =
     luatexbase.provides_module(luaotfload.module)
 
+luaotfload.error        = error
+luaotfload.warning      = warning
+luaotfload.info         = info
+luaotfload.log          = log
+
 %    \end{macrocode}
 %    We set the minimum version requirement for \LUATEX to v0.76,
 %    because the font loader requires recent features like direct
@@ -1542,7 +1547,6 @@ loadmodule"colors.lua"     --- “font-clr”
 % genuine \verb|name:| and \verb|file:| lookups of \LUATEX-Fonts.
 % Another benefit is that we can now easily plug in or replace new lookup
 % behaviors if necessary.
-%
 % The name resolver remains untouched, but it calls
 % \luafunction{fonts.names.resolve()} internally anyways (see
 % \fileent{luaotfload-database.lua}).
@@ -1683,10 +1687,12 @@ elseif font_definer == "patch"  then
                   1)
 end
 
-loadmodule"features.lua" --- contains what was “font-ltx” and “font-otc”
+loadmodule"features.lua"    --- contains what was “font-ltx” and “font-otc”
+loadmodule"auxiliary.lua"   --- additionaly high-level functionality (new)
 
 -- vim:tw=71:sw=4:ts=4:expandtab
 
+
 %    \end{macrocode}
 %
 % \iffalse
diff --git a/mkglyphlist b/mkglyphlist
index 9ee1528..d73a608 100755
--- a/mkglyphlist
+++ b/mkglyphlist
@@ -8,6 +8,12 @@
 --      VERSION:  1.0
 --      CREATED:  04/23/2013 12:42:17 PM CEST
 -----------------------------------------------------------------------
+-- interesting thread on the Context list:
+-- http://www.ntg.nl/pipermail/ntg-context/2008/029057.html
+-----------------------------------------------------------------------
+
+
+-----------------------------------------------------------------------
 --                              config
 -----------------------------------------------------------------------
 local glyphfile     = "./glyphlist.txt"
diff --git a/tests/font_patch.tex b/tests/font_patch.tex
index d41ff48..d3bba07 100644
--- a/tests/font_patch.tex
+++ b/tests/font_patch.tex
@@ -8,7 +8,11 @@
       mc.DisplayOperatorMinHeight = 2800 / em * sz
     end
   end
-  luatexbase.add_to_callback("luaotfload.patch_font", patch, "cambria.domh")
+  %% part of luaotfload-auxiliary
+  %luatexbase.add_to_callback(
+    %"luaotfload.patch_font",
+    %patch,
+    %"luaotfload.aux.patch_cambria_domh")
 }
 
 \font\4={name:Cambria Math:mode=base;script=math} at 10pt
diff --git a/tests/pln-aux-1.tex b/tests/pln-aux-1.tex
new file mode 100644
index 0000000..a504850
--- /dev/null
+++ b/tests/pln-aux-1.tex
@@ -0,0 +1,49 @@
+\input luaotfload.sty
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% usage for glyph tests
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\baselineskip=17.28pt
+
+\font\iwonaregular=name:iwona at 14.4pt
+\font\lmromanten=file:lmroman10-regular.otf at 14.4pt
+\font\cmuregular=file:cmunrm.otf at 14.4pt
+
+%% wrap tests in macros (could move to style file)
+\def\doifglyphelse#1#2#3{%
+  \directlua{
+    luaotfload.aux.do_if_glyph_else([[#1]], [[#2]], [[#3]])
+  }%
+}
+
+\def\doifglyph#1#2{\doifglyphelse{#1}{#2}{}}
+
+%% no otf font loaded yet, so both fail:
+first:
+\doifglyphelse{a}{true}{false}
+\doifglyph    {a}{yep}
+
+%% load lm and try repeat:
+\lmromanten
+second:
+\doifglyphelse{a}{true}{false}
+\doifglyph    {a}{yep}
+
+%% let’s test some more free fonts
+\def\checkglyphset{%
+  \doifglyphelse  ö{ö}{nope}
+  \doifglyphelse  п{п}{nope}
+  \doifglyphelse  α{α}{nope}
+  \doifglyphelse  Æ{Æ}{nope}
+  \doifglyphelse  ą{ą}{nope}
+  \doifglyphelse  ř{ř}{nope}
+  \doifglyphelse  ˝{˝}{nope}
+  \doifglyphelse  ѩ{ѩ}{nope}
+  \endgraf
+}
+
+\iwonaregular \checkglyphset
+\lmromanten   \checkglyphset
+\cmuregular   \checkglyphset
+
+\bye
diff --git a/tests/pln-aux-2.tex b/tests/pln-aux-2.tex
new file mode 100644
index 0000000..62192a5
--- /dev/null
+++ b/tests/pln-aux-2.tex
@@ -0,0 +1,102 @@
+\input luaotfload.sty
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% script, features, and language
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\font\minionregular=file:MinionPro_Regular.otf  at 9pt
+\font\biolinum=file:LinBiolinum_R.otf  at 9pt
+\font\cmuregular=file:cmunrm.otf  at 9pt
+
+%% (1) luaotfload.aux.provides_script(font_id, script)
+%%      #1 defined font; #2 OT script tag
+\def\providesscript[#1][#2]{%
+  \bgroup#1%
+  let’s see whether \detokenize{#1} has script #2:
+  \directlua{
+    local aux = luaotfload.aux
+    local succ = aux.provides_script(font.current(), [[#2]])
+    if succ then tex.sprint"true" else tex.sprint"false" end
+  }%
+  \egroup
+  \endgraf%
+}
+
+\providesscript [\minionregular][latn]%% Latin
+\providesscript      [\biolinum][latn]
+\providesscript    [\cmuregular][latn]
+\providesscript [\minionregular][cyrl]%% Cyrillic
+\providesscript      [\biolinum][cyrl]
+\providesscript    [\cmuregular][cyrl]
+\providesscript [\minionregular][tibt]%% Tibetan
+\providesscript      [\biolinum][tibt]
+\providesscript    [\cmuregular][tibt]
+
+\hrule % --------------------------------------------------------------
+
+%% (2) luaotfload.aux.provides_language(font_id, script, language)
+%%      #1 defined font; #2 OT script tag; #3 OT language tag
+\def\provideslanguage[#1][#2][#3]{%
+  \bgroup#1%
+  let’s see whether \detokenize{#1} supports language #3 for script #2:
+  \directlua{
+    local aux = luaotfload.aux
+    local succ = aux.provides_language(font.current(), [[#2]], [[#3]])
+    if succ then tex.sprint"true" else tex.sprint"false" end
+  }%
+  \egroup
+  \endgraf%
+}
+
+\provideslanguage [\minionregular][latn][nld]%% Latin/Dutch
+\provideslanguage      [\biolinum][latn][nld]
+\provideslanguage    [\cmuregular][latn][nld]
+\provideslanguage [\minionregular][latn][deu]%% Latin/German
+\provideslanguage      [\biolinum][latn][deu]
+\provideslanguage    [\cmuregular][latn][deu]
+\provideslanguage [\minionregular][cyrl][rus]%% Cyrillic/Russian
+\provideslanguage      [\biolinum][cyrl][rus]
+\provideslanguage    [\cmuregular][cyrl][rus]
+\provideslanguage [\minionregular][cyrl][klm]%% Cyrillic/Kalmyk
+\provideslanguage      [\biolinum][cyrl][klm]
+\provideslanguage    [\cmuregular][cyrl][klm]
+\provideslanguage [\minionregular][cyrl][srb]%% Cyrillic/Serbian
+\provideslanguage      [\biolinum][cyrl][srb]
+\provideslanguage    [\cmuregular][cyrl][srb]
+\provideslanguage [\minionregular][tibt][tib]%% Tibetan
+\provideslanguage      [\biolinum][tibt][tib]
+\provideslanguage    [\cmuregular][tibt][tib]
+
+\hrule % --------------------------------------------------------------
+
+%% (3) luaotfload.aux.provides_feature(
+%%                      font_id, script, language, feature)
+%%      #1 defined font;    #2 OT script tag;
+%%      #3 OT language tag; #4 OT feature
+\def\providesfeature[#1][#2][#3][#4]{%this is getting ridiculous
+  \bgroup#1%
+  let’s see whether \detokenize{#1} supports feature #4 for the
+  combination of script #2 with language #3:
+  \directlua{
+    local aux = luaotfload.aux
+    local succ = aux.provides_feature(
+      font.current(), [[#2]], [[#3]], [[#4]])
+    if succ then tex.sprint"true" else tex.sprint"false" end
+  }%
+  \egroup
+  \endgraf%
+}
+
+\providesfeature [\minionregular][latn][nld][liga]%% Latin/Dutch
+\providesfeature      [\biolinum][latn][nld][liga]
+\providesfeature    [\cmuregular][latn][nld][liga]
+\providesfeature [\minionregular][latn][deu][liga]%% Latin/German
+\providesfeature      [\biolinum][latn][deu][liga]
+\providesfeature    [\cmuregular][latn][deu][liga]
+\providesfeature [\minionregular][cyrl][srb][liga]%% Cyrillic/Serbian
+\providesfeature      [\biolinum][cyrl][srb][liga]
+\providesfeature    [\cmuregular][cyrl][srb][liga]
+\providesfeature [\minionregular][tibt][tib][liga]%% Tibetan
+\providesfeature      [\biolinum][tibt][tib][liga]
+\providesfeature    [\cmuregular][tibt][tib][liga]
+
+\bye
diff --git a/tests/pln-aux-3.tex b/tests/pln-aux-3.tex
new file mode 100644
index 0000000..12a80cf
--- /dev/null
+++ b/tests/pln-aux-3.tex
@@ -0,0 +1,39 @@
+\input luaotfload.sty
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% math dimension getter
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\font\xitsmath=file:xits-math.otf
+\font\cambriamath=file:cambria.ttc(1)
+
+\font\main=file:Iwona-Regular.otf at 12pt\main
+
+\directlua{
+  local aux = luaotfload.aux
+  local test_a = function (fontname, dimension)
+    tex.sprint(
+      "(", fontname, " (", dimension, " ",
+      aux.get_math_dimension(fontname, dimension),
+      [[))\endgraf ]])
+  end
+    
+  local test_b = function (fontname, dimension)
+    aux.sprint_math_dimension(fontname, dimension)
+    tex.print[[\endgraf ]]
+  end
+
+  test_a("xitsmath",     "AxisHeight")
+  test_a("xitsmath",     "RadicalVerticalGap")
+  test_a("cambriamath",  "StackTopShiftUp")
+  test_a("cambriamath",  "FractionNumeratorGapMin")
+
+  test_b("xitsmath",     "AxisHeight")
+  test_b("xitsmath",     "RadicalVerticalGap")
+  test_b("cambriamath",  "StackTopShiftUp")
+  test_b("cambriamath",  "FractionNumeratorGapMin")
+}
+
+foo bar baz
+
+\bye
diff --git a/tests/pln-aux-4.tex b/tests/pln-aux-4.tex
new file mode 100644
index 0000000..80ffc0b
--- /dev/null
+++ b/tests/pln-aux-4.tex
@@ -0,0 +1,41 @@
+\input luaotfload.sty
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% unicode character mappings
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+\font\ptserifregular = file:PTF55F.ttf \ptserifregular
+
+%% here we map the function luaotfload.aux.name_of_slot
+%% on a short text, printing a list of letters, their
+%% code points and names (as specified in the Adobe
+%% Glyph List).
+
+\directlua{
+  local aux = luaotfload.aux
+  local cbk = function (str)
+    if string.match(str, "^EOF") then
+      luatexbase.remove_from_callback("process_input_buffer", "weird")
+      return [[the end!]]
+    end
+    local res = { }
+    for chr in string.utfcharacters(str) do
+      local val = unicode.utf8.byte(chr)
+      local line = chr .. " <> " .. tostring(val)
+      line = line .. " <> " .. (aux.name_of_slot(val) or "")
+      res[\string#res+1] = line
+    end
+    return table.concat(res, [[\endgraf]])
+  end
+
+  luatexbase.add_to_callback("process_input_buffer", cbk, "weird")
+}
+
+Я узнал что у меня
+Есть огромная семья
+И тропинка и лесок
+В поле каждый колосок
+
+EOF
+
+\bye