[features] adapt tlig feature to extended ligature spec

1 files changed, 18 insertions, 5 deletions

diff --git a/src/luaotfload-features.lua b/src/luaotfload-features.lua
index 90487c0..1200d9e 100644
--- a/src/luaotfload-features.lua
+++ b/src/luaotfload-features.lua
@@ -6,7 +6,8 @@ if not modules then modules = { } end modules ["features"] = {
     license   = "see context related readme files"
 }
 
-local type, next        = type, next
+local type              = type
+local next              = next
 local tonumber          = tonumber
 local tostring          = tostring
 
@@ -16,6 +17,11 @@ local P                 = lpeg.P
 local R                 = lpeg.R
 local C                 = lpeg.C
 
+local table             = table
+local tabletohash       = table.tohash
+local setmetatableindex = table.setmetatableindex
+local insert            = table.insert
+
 ---[[ begin included font-ltx.lua ]]
 --- this appears to be based in part on luatex-fonts-def.lua
 
@@ -755,7 +761,7 @@ local verbosebaselines = swapped(baselines)
 
 --doc]]--
 
-local support_incomplete = table.tohash({
+local support_incomplete = tabletohash({
     "deva", "beng", "guru", "gujr",
     "orya", "taml", "telu", "knda",
     "mlym", "sinh",
@@ -983,7 +989,6 @@ local report_otf          = logs.reporter("fonts","otf loading")
 
 local otf                 = fonts.handlers.otf
 local registerotffeature  = otf.features.register
-local setmetatableindex   = table.setmetatableindex
 
 --[[HH--
 
@@ -1100,10 +1105,10 @@ local function addfeature(data,feature,specifications)
                     -- script = { lang1, lang2, lang3 } or script = { lang1 = true, ... }
                     for k, v in next, askedfeatures do
                         if v[1] then
-                            askedfeatures[k] = table.tohash(v)
+                            askedfeatures[k] = tabletohash(v)
                         end
                     end
-                    sequences[#sequences+1] = {
+                    local sequence = {
                         chain     = 0,
                         features  = { [feature] = askedfeatures },
                         flags     = featureflags,
@@ -1112,6 +1117,11 @@ local function addfeature(data,feature,specifications)
                         subtables = st,
                         type      = featuretype,
                     }
+                    if specification.prepend then
+                        insert(sequences,1,sequence)
+                    else
+                        insert(sequences,sequence)
+                    end
                     -- register in metadata (merge as there can be a few)
                     if not gsubfeatures then
                         gsubfeatures  = { }
@@ -1171,6 +1181,7 @@ local tlig = {
         },
         flags     = { },
         order     = { "tlig" },
+        prepend   = true,
     },
     {
         type     = "ligature",
@@ -1190,6 +1201,7 @@ local tlig = {
         },
         flags    = { },
         order    = { "tlig" },
+        prepend  = true,
     },
     {
         type     = "ligature",
@@ -1202,6 +1214,7 @@ local tlig = {
         },
         flags    = { },
         order    = { "tlig" },
+        prepend  = true,
     },
 }