[conf,db] allow switching back to fontforge

There are some non-negligible differences in the reader output,
especially concerning font names. Until this is sorted out we need a
fast way to switch back to the old code for reference.

2 files changed, 33 insertions, 4 deletions

diff --git a/src/luaotfload-configuration.lua b/src/luaotfload-configuration.lua
index 32e1417..f82c827 100644
--- a/src/luaotfload-configuration.lua
+++ b/src/luaotfload-configuration.lua
@@ -203,6 +203,7 @@ local default_config = {
     log_level      = 0,
     color_callback = "post_linebreak_filter",
     fontloader     = default_fontloader (),
+    use_fontforge  = false,
   },
   misc = {
     bisect         = false,
@@ -369,6 +370,18 @@ local set_default_features = function ()
   return true
 end
 
+local set_fontforge = function ()
+  if not _G.fontloader then
+    logreport ("both", 0, "db", "The fontloader library is missing.")
+    return false
+  end
+  local names = fonts.names
+  if names and names.use_fontforge then
+    logreport ("log", 0, "db", "Loading font data with FontForge.")
+    names.use_fontforge (true)
+  end
+  return true
+end
 
 reconf_tasks = {
   { "Set the log level"         , set_loglevel         },
@@ -377,6 +390,7 @@ reconf_tasks = {
   { "Set the font filter"       , set_font_filter      },
   { "Install font name resolver", set_name_resolver    },
   { "Set default features"      , set_default_features },
+  { "Set fontforge"             , set_fontforge        },
 }
 
 -------------------------------------------------------------------------------
@@ -509,6 +523,7 @@ local option_spec = {
                     id)
         return id
       end,
+      use_fontforge = { in_t = boolean_t, },
     },
     log_level = {
       in_t      = number_t,
@@ -672,6 +687,7 @@ local formatters = {
     fontloader      = { false, format_string  },
     log_level       = { false, format_integer },
     resolver        = { false, format_string  },
+    use_fontforge   = { false, format_boolean },
   },
 }
 
diff --git a/src/luaotfload-database.lua b/src/luaotfload-database.lua
index 58ad2ab..7c5e69b 100644
--- a/src/luaotfload-database.lua
+++ b/src/luaotfload-database.lua
@@ -58,7 +58,8 @@ local fontshandlers            = fonts.handlers     or { }
 local otfhandler               = fonts.handlers.otf or { }
 fonts.handlers                 = fontshandlers
 
-local otfreadersgetinfo        = otfhandler.readers.getinfo
+local read_font_file           = otfhandler.readers.getinfo
+local read_font_info           = read_font_file
 
 local gzipload                 = gzip.load
 local gzipsave                 = gzip.save
@@ -1228,7 +1229,7 @@ find_closest = function (name, limit)
 end --- find_closest()
 
 local load_font_file = function (filename, subfont)
-    local rawfont, _msg = otfreadersgetinfo (filename, subfont)
+    local rawfont, _msg = read_font_file (filename, subfont)
     if not rawfont then
         logreport ("log", 1, "db", "ERROR: failed to open %s.", filename)
         return
@@ -1695,7 +1696,7 @@ local read_font_names = function (fullname,
 
     --- 4) get basic info, abort if fontloader can’t read it
 
-    local info = otfreadersgetinfo (fullname)
+    local info = read_font_file (fullname)
 
     if not info then
         logreport ("log", 1, "db",
@@ -3419,6 +3420,17 @@ local show_cache = function ( )
     return true
 end
 
+local use_fontforge = function (val)
+    if val == true then
+        local fontloader = fontloader
+        read_font_info   = fontloader.info
+        read_font_file   = fontloader.open
+    else
+        read_font_file   = otfhandler.readers.getinfo
+        read_font_info   = read_font_file
+    end
+end
+
 -----------------------------------------------------------------------
 --- export functionality to the namespace “fonts.names”
 -----------------------------------------------------------------------
@@ -3449,7 +3461,8 @@ local export = {
     erase_cache                 = erase_cache,
     show_cache                  = show_cache,
     find_closest                = find_closest,
-    -- for testing purpose
+    --- transitionary
+    use_fontforge               = use_fontforge,
 }
 
 return {