Merge pull request #276 from phi-gamma/master

fixes; current progress regarding initialization

5 files changed, 400 insertions, 303 deletions

diff --git a/src/luaotfload-database.lua b/src/luaotfload-database.lua
index 099c256..1831ca3 100644
--- a/src/luaotfload-database.lua
+++ b/src/luaotfload-database.lua
@@ -482,8 +482,8 @@ local fonts_reloaded = false
 --- limit output when approximate font matching (luaotfload-tool -F)
 local fuzzy_limit = 1 --- display closest only
 
---- bool? -> dbobj
-load_names = function (dry_run)
+--- bool? -> -> bool? -> dbobj option
+load_names = function (dry_run, no_rebuild)
     local starttime = osgettimeofday ()
     local foundname, data = load_lua_file (config.luaotfload.paths.index_path_lua)
 
@@ -519,6 +519,11 @@ load_names = function (dry_run)
             end
         end
     else
+        if no_rebuild == true then
+            report ("both", 2, "db",
+                    [[Database does not exist, skipping rebuild though.]])
+            return false
+        end
         report ("both", 0, "db",
                 [[Font names database not found, generating new one.]])
         report ("both", 0, "db",
@@ -545,8 +550,11 @@ access_font_index = function ()
 end
 
 getmetadata = function ()
-    if not name_index then name_index = load_names() end
-    return tablefastcopy (name_index.meta)
+    if not name_index then
+        name_index = load_names (false, true)
+        if name_index then return tablefastcopy (name_index.meta) end
+    end
+    return false
 end
 
 --- unit -> unit
diff --git a/src/luaotfload-init.lua b/src/luaotfload-init.lua
index 4968877..feff4cc 100644
--- a/src/luaotfload-init.lua
+++ b/src/luaotfload-init.lua
@@ -30,30 +30,305 @@
 
 --doc]]--
 
-config                          = config or { }
-local config                    = config
-config.luaotfload               = config.luaotfload or { }
+local log        --- filled in after loading the log module
+local logreport  --- filled in after loading the log module
 
-config.lualibs                  = config.lualibs or { }
-config.lualibs.verbose          = false
-config.lualibs.prefer_merged    = true
-config.lualibs.load_extended    = true
+--[[doc--
+
+    \subsection{Preparing the Font Loader}
+    We treat the fontloader as a black box so behavior is consistent
+    between formats.
+    We load the fontloader code directly in the same fashion as the
+    Plain format \identifier{luatex-fonts} that is part of Context.
+    How this is executed depends on the presence on the
+    \emphasis{merged font loader code}.
+    In \identifier{luaotfload} this is contained in the file
+    \fileent{luaotfload-merged.lua}.
+    If this file cannot be found, the original libraries from \CONTEXT
+    of which the merged code was composed are loaded instead.
+    Since these files are not shipped with Luaotfload, an installation
+    of Context is required.
+    (Since we pull the fontloader directly from the Context minimals,
+    the necessary Context version is likely to be more recent than that
+    of other TeX distributions like Texlive.)
+    The imported font loader will call \luafunction{callback.register}
+    once while reading \fileent{font-def.lua}.
+    This is unavoidable unless we modify the imported files, but
+    harmless if we make it call a dummy instead.
+    However, this problem might vanish if we decide to do the merging
+    ourselves, like the \identifier{lualibs} package does.
+    With this step we would obtain the freedom to load our own
+    overrides in the process right where they are needed, at the cost
+    of losing encapsulation.
+    The decision on how to progress is currently on indefinite hold.
 
-require "lualibs"
+--doc]]--
 
-if not lualibs    then error("this module requires Luaotfload") end
-if not luaotfload then error("this module requires Luaotfload") end
 
-local load_luaotfload_module = luaotfload.loaders.luaotfload
-local load_fontloader_module = luaotfload.loaders.fontloader
+local init_pre = function ()
 
---[[doc--
+  local store                  = { }
+  config                       = config or { } --- global
+  config.luaotfload            = config.luaotfload or { }
+  config.lualibs               = config.lualibs    or { }
+  config.lualibs.verbose       = false
+  config.lualibs.prefer_merged = true
+  config.lualibs.load_extended = true
+
+  require "lualibs"
+
+  if not lualibs    then error "this module requires Luaotfload" end
+  if not luaotfload then error "this module requires Luaotfload" end
+
+  --[[doc--
 
     The logger needs to be in place prior to loading the fontloader due
     to order of initialization being crucial for the logger functions
     that are swapped.
 
+  --doc]]--
+
+  luaotfload.loaders.luaotfload "log"
+  log       = luaotfload.log
+  logreport = log.report
+  log.set_loglevel (default_log_level)
+
+  logreport ("log", 4, "init", "Concealing callback.register().")
+  store.trapped_register = callback.register
+
+  callback.register = function (id)
+    logreport ("log", 4, "init",
+               "Dummy callback.register() invoked on %s.",
+               id)
+  end
+
+  --[[doc--
+
+    By default, the fontloader requires a number of \emphasis{private
+    attributes} for internal use.
+    These must be kept consistent with the attribute handling methods
+    as provided by \identifier{luatexbase}.
+    Our strategy is to override the function that allocates new
+    attributes before we initialize the font loader, making it a
+    wrapper around \luafunction{luatexbase.new_attribute}.\footnote{%
+        Many thanks, again, to Hans Hagen for making this part
+        configurable!
+    }
+    The attribute identifiers are prefixed “\fileent{luaotfload@}” to
+    avoid name clashes.
+
+  --doc]]--
+
+  local new_attribute    = luatexbase.new_attribute
+  local the_attributes   = luatexbase.attributes
+
+  attributes = attributes or { } --- this writes a global, sorry
+
+  attributes.private = function (name)
+    local attr   = "luaotfload@" .. name --- used to be: “otfl@”
+    local number = the_attributes[attr]
+    if not number then number = new_attribute(attr) end
+    return number
+  end
+
+  return store
+end --- [init_pre]
+
+--[[doc--
+
+    These next lines replicate the behavior of
+    \fileent{luatex-fonts.lua}.
+
 --doc]]--
 
-load_luaotfload_module "log"
+local push_namespaces = function ()
+    logreport ("log", 4, "init", "push namespace for font loader")
+    local normalglobal = { }
+    for k, v in next, _G do
+        normalglobal[k] = v
+    end
+    return normalglobal
+end
+
+local pop_namespaces = function (normalglobal,
+                                 isolate,
+                                 context_environment)
+    if normalglobal then
+        local _G = _G
+        local mode = "non-destructive"
+        if isolate then mode = "destructive" end
+        logreport ("log", 4, "init", "pop namespace from font loader -- " .. mode)
+        for k, v in next, _G do
+            if not normalglobal[k] then
+                context_environment[k] = v
+                if isolate then
+                    _G[k] = nil
+                end
+            end
+        end
+        for k, v in next, normalglobal do
+            _G[k] = v
+        end
+        -- just to be sure:
+        setmetatable(context_environment, _G)
+    else
+        logreport ("both", 0, "init",
+                   "irrecoverable error during pop_namespace: no globals to restore")
+        os.exit ()
+    end
+end
+
+local init_adapt = function ()
+
+  luaotfload.context_environment  = { }
+  luaotfload.push_namespaces      = push_namespaces
+  luaotfload.pop_namespaces       = pop_namespaces
+
+  local our_environment = push_namespaces ()
+
+  --[[doc--
+
+      The font loader requires that the attribute with index zero be
+      zero. We happily oblige.
+      (Cf. \fileent{luatex-fonts-nod.lua}.)
+
+  --doc]]--
+
+  tex.attribute[0] = 0
+
+  return our_environment
+
+end --- [init_adapt]
+
+local init_main = function ()
+
+  local load_fontloader_module = luaotfload.loaders.fontloader
+
+  --[[doc--
+
+      Now that things are sorted out we can finally load the
+      fontloader.
+
+      For less current distibutions we ship the code from TL 2014 that
+      should be compatible with Luatex 0.76.
+
+  --doc]]--
+
+  load_fontloader_module (luaotfload.fontloader_package)
+
+  ---load_fontloader_module "font-odv.lua" --- <= Devanagari support from Context
+
+  if not fonts then
+    --- the loading sequence is known to change, so this might have to
+    --- be updated with future updates!
+    --- do not modify it though unless there is a change to the merged
+    --- package!
+    load_fontloader_module "l-lua"
+    load_fontloader_module "l-lpeg"
+    load_fontloader_module "l-function"
+    load_fontloader_module "l-string"
+    load_fontloader_module "l-table"
+    load_fontloader_module "l-io"
+    load_fontloader_module "l-file"
+    load_fontloader_module "l-boolean"
+    load_fontloader_module "l-math"
+    load_fontloader_module "util-str"
+    load_fontloader_module "luatex-basics-gen"
+    load_fontloader_module "data-con"
+    load_fontloader_module "luatex-basics-nod"
+    load_fontloader_module "font-ini"
+    load_fontloader_module "font-con"
+    load_fontloader_module "luatex-fonts-enc"
+    load_fontloader_module "font-cid"
+    load_fontloader_module "font-map"
+    load_fontloader_module "luatex-fonts-syn"
+    load_fontloader_module "luatex-fonts-tfm"
+    load_fontloader_module "font-oti"
+    load_fontloader_module "font-otf"
+    load_fontloader_module "font-otb"
+    load_fontloader_module "luatex-fonts-inj"  --> since 2014-01-07, replaces node-inj.lua
+    load_fontloader_module "luatex-fonts-ota"
+    load_fontloader_module "luatex-fonts-otn"  --> since 2014-01-07, replaces font-otn.lua
+    load_fontloader_module "font-otp"          --> since 2013-04-23
+    load_fontloader_module "luatex-fonts-lua"
+    load_fontloader_module "font-def"
+    load_fontloader_module "luatex-fonts-def"
+    load_fontloader_module "luatex-fonts-ext"
+    load_fontloader_module "luatex-fonts-cbk"
+  end --- non-merge fallback scope
+
+end --- [init_main]
+
+local init_cleanup = function (store)
+  --- reinstate all the stuff we had to move out of the way to
+  --- accomodate the loader
+
+  --[[doc--
+
+      Here we adjust the globals created during font loader
+      initialization. If the second argument to
+      \luafunction{pop_namespaces()} is \verb|true| this will restore the
+      state of \luafunction{_G}, eliminating every global generated since
+      the last call to \luafunction{push_namespaces()}. At the moment we
+      see no reason to do this, and since the font loader is considered
+      an essential part of \identifier{luatex} as well as a very well
+      organized piece of code, we happily concede it the right to add to
+      \luafunction{_G} if needed.
+
+  --doc]]--
+
+  luaotfload.pop_namespaces (store.our_environment,
+                             false,
+                             luaotfload.context_environment)
+
+  --[[doc--
+
+      \subsection{Callbacks}
+        After the fontloader is ready we can restore the callback trap
+        from \identifier{luatexbase}.
+
+  --doc]]--
+
+  logreport ("log", 4, "init",
+             "Restoring original callback.register().")
+  callback.register = store.trapped_register
+end --- [init_cleanup]
+
+local init_post = function ()
+  --- hook for actions that need to take place after the fontloader is
+  --- installed
+
+  --[[doc--
+
+    we do our own callback handling with the means provided by
+    luatexbase.
+    note: \luafunction{pre_linebreak_filter} and
+    \luafunction{hpack_filter} are coupled in \context in the
+    concept of \emphasis{node processor}.
+
+  --doc]]--
+
+  luatexbase.add_to_callback("pre_linebreak_filter",
+                             nodes.simple_font_handler,
+                             "luaotfload.node_processor",
+                             1)
+  luatexbase.add_to_callback("hpack_filter",
+                             nodes.simple_font_handler,
+                             "luaotfload.node_processor",
+                             1)
+end --- [init_post]
+
+return {
+  init = function ()
+    local starttime = os.gettimeofday ()
+    local store = init_pre ()
+    store.our_environment = init_adapt ()
+    init_main ()
+    init_cleanup (store)
+    logreport ("both", 1, "init",
+               "fontloader loaded in %0.3f seconds",
+               os.gettimeofday() - starttime)
+    init_post ()
+  end
+}
 
diff --git a/src/luaotfload-main.lua b/src/luaotfload-main.lua
index a825dc3..e8f05d6 100644
--- a/src/luaotfload-main.lua
+++ b/src/luaotfload-main.lua
@@ -19,6 +19,10 @@ local luaotfload                  = luaotfload
 luaotfload.log                    = luaotfload.log or { }
 luaotfload.version                = "2.6"
 luaotfload.loaders                = { }
+luaotfload.min_luatex_version     = 79             --- i. e. 0.79
+luaotfload.fontloader_package     = "fontloader"   --- default: from current Context
+----------.fontloader_package     = "slim"
+
 
 local authors = "\z
     Hans Hagen,\z
@@ -104,16 +108,12 @@ luaotfload.log.tex        = {
 
 --doc]]--
 
-local min_luatex_version  = 79             --- i. e. 0.79
---local fontloader_package  = "fontloader"   --- default: from current Context
-local fontloader_package  = "slim"
-
-if tex.luatexversion < min_luatex_version then
+if tex.luatexversion < luaotfload.min_luatex_version then
     warning ("LuaTeX v%.2f is old, v%.2f or later is recommended.",
              tex.luatexversion  / 100,
-             min_luatex_version / 100)
+             luaotfload.min_luatex_version / 100)
     warning ("using fallback fontloader -- newer functionality not available")
-    fontloader_package = "tl2014" --- TODO fallback should be configurable too
+    luaotfload.fontloader_package = "tl2014" --- TODO fallback should be configurable too
     --- we install a fallback for older versions as a safety
 end
 
@@ -126,9 +126,25 @@ end
 
 --doc]]--
 
+local make_loader_name = function (prefix, name)
+    local msg = luaotfload.log and luaotfload.log.report or print
+    if prefix then
+        msg ("log", 7, "load",
+             "Composing fontloader name from constitutents %s, %s",
+             prefix, name)
+        return prefix .. "-" .. name .. ".lua"
+    end
+    msg ("log", 7, "load",
+         "Loading fontloader file %s literally.",
+         name)
+    return name
+end
+
 local make_loader = function (prefix)
-    return prefix and function (name) require (prefix .. "-" .. name .. ".lua") end
-                   or function (name) require (name)                            end
+    return function (name)
+        local modname = make_loader_name (prefix, name)
+        return require (modname)
+    end
 end
 
 local load_luaotfload_module = make_loader "luaotfload"
@@ -138,255 +154,12 @@ local load_fontloader_module = make_loader "fontloader"
 luaotfload.loaders.luaotfload = load_luaotfload_module
 luaotfload.loaders.fontloader = load_fontloader_module
 
-load_luaotfload_module "init" --- fontloader initialization
+luaotfload.init = load_luaotfload_module "init" --- fontloader initialization
+luaotfload.init.init ()
 
 local log             = luaotfload.log
 local logreport       = log.report
 
-log.set_loglevel (default_log_level)
-
---[[doc--
-
-    \subsection{Preparing the Font Loader}
-    We treat the fontloader as a black box so behavior is consistent
-    between formats.
-    We load the fontloader code directly in the same fashion as the
-    Plain format \identifier{luatex-fonts} that is part of Context.
-    How this is executed depends on the presence on the
-    \emphasis{merged font loader code}.
-    In \identifier{luaotfload} this is contained in the file
-    \fileent{luaotfload-merged.lua}.
-    If this file cannot be found, the original libraries from \CONTEXT
-    of which the merged code was composed are loaded instead.
-    Since these files are not shipped with Luaotfload, an installation
-    of Context is required.
-    (Since we pull the fontloader directly from the Context minimals,
-    the necessary Context version is likely to be more recent than that
-    of other TeX distributions like Texlive.)
-    The imported font loader will call \luafunction{callback.register}
-    once while reading \fileent{font-def.lua}.
-    This is unavoidable unless we modify the imported files, but
-    harmless if we make it call a dummy instead.
-    However, this problem might vanish if we decide to do the merging
-    ourselves, like the \identifier{lualibs} package does.
-    With this step we would obtain the freedom to load our own
-    overrides in the process right where they are needed, at the cost
-    of losing encapsulation.
-    The decision on how to progress is currently on indefinite hold.
-
---doc]]--
-
-local starttime         = os.gettimeofday ()
-local trapped_register  = callback.register
-callback.register       = dummy_function
-
---[[doc--
-
-    By default, the fontloader requires a number of \emphasis{private
-    attributes} for internal use.
-    These must be kept consistent with the attribute handling methods
-    as provided by \identifier{luatexbase}.
-    Our strategy is to override the function that allocates new
-    attributes before we initialize the font loader, making it a
-    wrapper around \luafunction{luatexbase.new_attribute}.\footnote{%
-        Many thanks, again, to Hans Hagen for making this part
-        configurable!
-    }
-    The attribute identifiers are prefixed “\fileent{luaotfload@}” to
-    avoid name clashes.
-
---doc]]--
-
-do
-    local new_attribute    = luatexbase.new_attribute
-    local the_attributes   = luatexbase.attributes
-
-    attributes = attributes or { }
-
-    attributes.private = function (name)
-        local attr   = "luaotfload@" .. name --- used to be: “otfl@”
-        local number = the_attributes[attr]
-        if not number then
-            number = new_attribute(attr)
-        end
-        return number
-    end
-end
-
---[[doc--
-
-    These next lines replicate the behavior of
-    \fileent{luatex-fonts.lua}.
-
---doc]]--
-
-local context_environment = { }
-
-local push_namespaces = function ()
-    logreport ("log", 1, "main", "push namespace for font loader")
-    local normalglobal = { }
-    for k, v in next, _G do
-        normalglobal[k] = v
-    end
-    return normalglobal
-end
-
-local pop_namespaces = function (normalglobal, isolate)
-    if normalglobal then
-        local _G = _G
-        local mode = "non-destructive"
-        if isolate then mode = "destructive" end
-        logreport ("log", 1, "main", "pop namespace from font loader -- " .. mode)
-        for k, v in next, _G do
-            if not normalglobal[k] then
-                context_environment[k] = v
-                if isolate then
-                    _G[k] = nil
-                end
-            end
-        end
-        for k, v in next, normalglobal do
-            _G[k] = v
-        end
-        -- just to be sure:
-        setmetatable(context_environment,_G)
-    else
-        logreport ("both", 0, "main",
-                   "irrecoverable error during pop_namespace: no globals to restore")
-        os.exit()
-    end
-end
-
-luaotfload.context_environment  = context_environment
-luaotfload.push_namespaces      = push_namespaces
-luaotfload.pop_namespaces       = pop_namespaces
-
-local our_environment = push_namespaces()
-
---[[doc--
-
-    The font loader requires that the attribute with index zero be
-    zero. We happily oblige.
-    (Cf. \fileent{luatex-fonts-nod.lua}.)
-
---doc]]--
-
-tex.attribute[0] = 0
-
---[[doc--
-
-    Now that things are sorted out we can finally load the fontloader.
-
-    For less current distibutions we ship the code from TL 2014 that should be
-    compatible with Luatex 0.76.
-
---doc]]--
-
-load_fontloader_module (fontloader_package)
-
----load_fontloader_module "font-odv.lua" --- <= Devanagari support from Context
-
-if fonts then
-
-    --- The Initialization is highly idiosyncratic.
-
-    if not fonts._merge_loaded_message_done_ then
-        logreport ("log", 5, "main", [["I am using the merged fontloader here.]])
-        logreport ("log", 5, "main", [[ If you run into problems or experience unexpected]])
-        logreport ("log", 5, "main", [[ behaviour, and if you have ConTeXt installed you can try]])
-        logreport ("log", 5, "main", [[ to delete the file 'fontloader-fontloader.lua' as I might]])
-        logreport ("log", 5, "main", [[ then use the possibly updated libraries. The merged]])
-        logreport ("log", 5, "main", [[ version is not supported as it is a frozen instance.]])
-        logreport ("log", 5, "main", [[ Problems can be reported to the ConTeXt mailing list."]])
-    end
-    fonts._merge_loaded_message_done_ = true
-
-else--- the loading sequence is known to change, so this might have to
-    --- be updated with future updates!
-    --- do not modify it though unless there is a change to the merged
-    --- package!
-    load_fontloader_module "l-lua"
-    load_fontloader_module "l-lpeg"
-    load_fontloader_module "l-function"
-    load_fontloader_module "l-string"
-    load_fontloader_module "l-table"
-    load_fontloader_module "l-io"
-    load_fontloader_module "l-file"
-    load_fontloader_module "l-boolean"
-    load_fontloader_module "l-math"
-    load_fontloader_module "util-str"
-    load_fontloader_module "luatex-basics-gen"
-    load_fontloader_module "data-con"
-    load_fontloader_module "luatex-basics-nod"
-    load_fontloader_module "font-ini"
-    load_fontloader_module "font-con"
-    load_fontloader_module "luatex-fonts-enc"
-    load_fontloader_module "font-cid"
-    load_fontloader_module "font-map"
-    load_fontloader_module "luatex-fonts-syn"
-    load_fontloader_module "luatex-fonts-tfm"
-    load_fontloader_module "font-oti"
-    load_fontloader_module "font-otf"
-    load_fontloader_module "font-otb"
-    load_fontloader_module "luatex-fonts-inj"  --> since 2014-01-07, replaces node-inj.lua
-    load_fontloader_module "luatex-fonts-ota"
-    load_fontloader_module "luatex-fonts-otn"  --> since 2014-01-07, replaces font-otn.lua
-    load_fontloader_module "font-otp"          --> since 2013-04-23
-    load_fontloader_module "luatex-fonts-lua"
-    load_fontloader_module "font-def"
-    load_fontloader_module "luatex-fonts-def"
-    load_fontloader_module "luatex-fonts-ext"
-    load_fontloader_module "luatex-fonts-cbk"
-end --- non-merge fallback scope
-
---[[doc--
-
-    Here we adjust the globals created during font loader
-    initialization. If the second argument to
-    \luafunction{pop_namespaces()} is \verb|true| this will restore the
-    state of \luafunction{_G}, eliminating every global generated since
-    the last call to \luafunction{push_namespaces()}. At the moment we
-    see no reason to do this, and since the font loader is considered
-    an essential part of \identifier{luatex} as well as a very well
-    organized piece of code, we happily concede it the right to add to
-    \luafunction{_G} if needed.
-
---doc]]--
-
-pop_namespaces(our_environment, false)-- true)
-
-logreport ("both", 1, "main",
-           "fontloader loaded in %0.3f seconds", os.gettimeofday()-starttime)
-
---[[doc--
-
-    \subsection{Callbacks}
-    After the fontloader is ready we can restore the callback trap from
-    \identifier{luatexbase}.
-
---doc]]--
-
-callback.register = trapped_register
-
---[[doc--
-
-    We do our own callback handling with the means provided by
-    luatexbase.
-    Note: \luafunction{pre_linebreak_filter} and
-    \luafunction{hpack_filter} are coupled in \CONTEXT in the concept
-    of \emphasis{node processor}.
-
---doc]]--
-
-add_to_callback("pre_linebreak_filter",
-                nodes.simple_font_handler,
-                "luaotfload.node_processor",
-                1)
-add_to_callback("hpack_filter",
-                nodes.simple_font_handler,
-                "luaotfload.node_processor",
-                1)
-
 load_luaotfload_module "override"   --- load glyphlist on demand
 
 --[[doc--
diff --git a/src/luaotfload-parsers.lua b/src/luaotfload-parsers.lua
index 3a4faea..a52b5d4 100644
--- a/src/luaotfload-parsers.lua
+++ b/src/luaotfload-parsers.lua
@@ -17,9 +17,11 @@ if not modules then modules = { } end modules ['luaotfload-parsers'] = {
   license   = "GNU GPL v2.0"
 }
 
-luaotfload              = luaotfload or { }
-luaotfload.parsers      = luaotfload.parsers or { }
-local parsers           = luaotfload.parsers
+luaotfload                 = luaotfload or { }
+luaotfload.parsers         = luaotfload.parsers or { }
+local parsers              = luaotfload.parsers
+parsers.traversal_maxdepth = 42 --- prevent stack overflows
+local traversal_maxdepth   = parsers.traversal_maxdepth --- TODO could be an option
 
 local rawset            = rawset
 
@@ -190,6 +192,7 @@ local p_cheapxml          = header * root
 --doc]]--
 --- string -> path list
 local fonts_conf_scanner = function (path)
+  logreport("both", 5, "db", "Read fontconfig file %s.", path)
   local fh = ioopen(path, "r")
   if not fh then
     logreport("both", 3, "db", "Cannot open fontconfig file %s.", path)
@@ -197,12 +200,17 @@ local fonts_conf_scanner = function (path)
   end
   local raw = fh:read"*all"
   fh:close()
+  logreport("both", 7, "db",
+            "Reading fontconfig file %s completed (%d bytes).",
+            path, #raw)
 
+  logreport("both", 5, "db", "Scan fontconfig file %s.", path)
   local confdata = lpegmatch(p_cheapxml, raw)
   if not confdata then
     logreport("both", 3, "db", "Cannot scan fontconfig file %s.", path)
     return
   end
+  logreport("both", 7, "db", "Scan of fontconfig file %s completed.", path)
   return confdata
 end
 
@@ -220,8 +228,9 @@ end
 
       read_fonts_conf_indeed() -- Scan paths included from fontconfig
       configuration files recursively. Called with eight arguments.
-      The first four are
+      The first five are
 
+          · the current recursion depth
           · the path to the file
           · the expanded $HOME
           · the expanded $XDG_CONFIG_HOME
@@ -234,12 +243,13 @@ end
 
 --doc]]--
 
---- string -> string -> string -> string
+--- size_t -> string -> string -> string -> string
 ---     -> string list -> string list -> string list
 ---     -> (string -> fun option -> string list)
 ---     -> tab * tab * tab
 local read_fonts_conf_indeed
-read_fonts_conf_indeed = function (start,
+read_fonts_conf_indeed = function (depth,
+                                   start,
                                    home,
                                    xdg_config_home,
                                    xdg_data_home,
@@ -248,6 +258,18 @@ read_fonts_conf_indeed = function (start,
                                    dirs_done,
                                    find_files)
 
+  logreport ("both", 4, "db",
+             "Fontconfig scanner processing path %s.",
+             start)
+  if depth >= traversal_maxdepth then
+    --- prevent overflow of Lua call stack
+    logreport ("both", 0, "db",
+               "Fontconfig scanner hit recursion limit (%d); "
+               .. "aborting directory traversal.",
+               traversal_maxdepth)
+    return acc, done, dirs_done
+  end
+
   local paths = fonts_conf_scanner(start)
   if not paths then --- nothing to do
     return acc, done, dirs_done
@@ -273,6 +295,9 @@ read_fonts_conf_indeed = function (start,
       --- distributions (e.g. Context minimals) installed
       --- separately?
       if not (stringfind(path, "texmf") or dirs_done[path]) then
+        logreport ("log", 5, "db",
+                   "New fontconfig path at %s.",
+                   path)
         acc[#acc+1] = path
         dirs_done[path] = true
       end
@@ -292,34 +317,45 @@ read_fonts_conf_indeed = function (start,
       end
       if  lfsisfile(path)
         and kpsereadable_file(path)
-        and not done[path]
       then
-        --- we exclude path with texmf in them, as they should
-        --- be found otherwise
-        acc = read_fonts_conf_indeed(path,
-                                     home,
-                                     xdg_config_home,
-                                     xdg_data_home,
-                                     acc,
-                                     done,
-                                     dirs_done,
-                                     find_files)
+        if done[path] then
+          logreport("log", 3, "db",
+                    "Skipping file at %s, already included.", path)
+        else
+          done[path] = true
+          acc = read_fonts_conf_indeed(depth + 1,
+                                       path,
+                                       home,
+                                       xdg_config_home,
+                                       xdg_data_home,
+                                       acc,
+                                       done,
+                                       dirs_done,
+                                       find_files)
+        end
       elseif lfsisdir(path) then --- arrow code ahead
         local config_files = find_files (path, conf_filter)
         for _, filename in next, config_files do
           if not done[filename] then
-            acc = read_fonts_conf_indeed(filename,
-                                         home,
-                                         xdg_config_home,
-                                         xdg_data_home,
-                                         acc,
-                                         done,
-                                         dirs_done,
-                                         find_files)
+            if done[path] then
+              logreport ("log", 3, "db",
+                         "Skipping file at %s, already included.", path)
+            else
+              done[path] = true
+              acc = read_fonts_conf_indeed(depth + 1,
+                                           filename,
+                                           home,
+                                           xdg_config_home,
+                                           xdg_data_home,
+                                           acc,
+                                           done,
+                                           dirs_done,
+                                           find_files)
+            end
           end
         end
       end --- match “kind”
-      end --- iterate paths
+    end --- iterate paths
   end
 
   --inspect(acc)
@@ -350,7 +386,8 @@ local read_fonts_conf = function (path_list, find_files)
   local done      = { } ---> set:  files inspected
   local dirs_done = { } ---> set:  dirs in list
   for i=1, #path_list do --- we keep the state between files
-    acc, done, dirs_done = read_fonts_conf_indeed(path_list[i],
+    acc, done, dirs_done = read_fonts_conf_indeed(0,
+                                                  path_list[i],
                                                   home,
                                                   xdg_config_home,
                                                   xdg_data_home,
diff --git a/src/luaotfload-tool.lua b/src/luaotfload-tool.lua
index 36c23bd..e240e4c 100755
--- a/src/luaotfload-tool.lua
+++ b/src/luaotfload-tool.lua
@@ -288,10 +288,14 @@ local version_msg = function ( )
         local var = uname_vars[i]
         out ("    + %8s: %s", var, uname[var])
     end
-    out ("Index: version=%q created=%q modified=%q",
-         config.luaotfload.status.notes.revision,
-         meta.created or "ages ago",
-         meta.modified or "ages ago")
+    if meta == false then
+        out("No database metadata available.")
+    else
+        out ("Index: version=%q created=%q modified=%q",
+             config.luaotfload.status.notes.revision,
+             meta.created or "ages ago",
+             meta.modified or "ages ago")
+    end
     out ""
 end