[fontloader] sync with Context as of 2015-10-29

1 files changed, 236 insertions, 139 deletions

diff --git a/src/fontloader/misc/fontloader-fonts-inj.lua b/src/fontloader/misc/fontloader-fonts-inj.lua
index 332e920..36781f7 100644
--- a/src/fontloader/misc/fontloader-fonts-inj.lua
+++ b/src/fontloader/misc/fontloader-fonts-inj.lua
@@ -8,7 +8,16 @@ if not modules then modules = { } end modules ['font-inj'] = {
 
 -- This property based variant is not faster but looks nicer than the attribute one. We
 -- need to use rawget (which is apbout 4 times slower than a direct access but we cannot
--- get/set that one for our purpose!
+-- get/set that one for our purpose! This version does a bit more with discretionaries
+-- (and Kai has tested it with his collection of weird fonts.)
+
+-- There is some duplicate code here (especially in the the pre/post/replace branches) but
+-- we go for speed. We could store a list of glyph and mark nodes when registering but it's
+-- cleaner to have an identification pass here. Also, I need to keep tracing in mind so
+-- being too clever here is dangerous.
+
+-- The subtype test is not needed as there will be no (new) properties set, given that we
+-- reset the properties.
 
 if not nodes.properties then return end
 
@@ -80,8 +89,7 @@ function injections.resetcounts()
     keepregisteredcounts  = false
 end
 
--- We need to make sure that a possible metatable will not kick in
--- unexpectedly.
+-- We need to make sure that a possible metatable will not kick in unexpectedly.
 
 function injections.reset(n)
     local p = rawget(properties,n)
@@ -146,7 +154,8 @@ end
 function injections.setcursive(start,nxt,factor,rlmode,exit,entry,tfmstart,tfmnext) -- hm: nuts or nodes
     local dx =  factor*(exit[1]-entry[1])
     local dy = -factor*(exit[2]-entry[2])
-    local ws, wn = tfmstart.width, tfmnext.width
+    local ws = tfmstart.width
+    local wn = tfmnext.width
     nofregisteredcursives = nofregisteredcursives + 1
     if rlmode < 0 then
         dx = -(dx + wn)
@@ -195,7 +204,10 @@ function injections.setcursive(start,nxt,factor,rlmode,exit,entry,tfmstart,tfmne
 end
 
 function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2lflag & tfmchr not used
-    local x, y, w, h = factor*spec[1], factor*spec[2], factor*spec[3], factor*spec[4]
+    local x = factor*spec[1]
+    local y = factor*spec[2]
+    local w = factor*spec[3]
+    local h = factor*spec[4]
     if x ~= 0 or w ~= 0 or y ~= 0 or h ~= 0 then -- okay?
         local yoffset   = y - h
         local leftkern  = x      -- both kerns are set in a pair kern compared
@@ -205,9 +217,12 @@ function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2l
             if rlmode and rlmode < 0 then
                 leftkern, rightkern = rightkern, leftkern
             end
+            if not injection then
+                injection = "injections"
+            end
             local p = rawget(properties,current)
             if p then
-                local i = rawget(p,"injections")
+                local i = rawget(p,injection)
                 if i then
                     if leftkern ~= 0 then
                         i.leftkern  = (i.leftkern  or 0) + leftkern
@@ -219,19 +234,19 @@ function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2l
                         i.yoffset = (i.yoffset or 0) + yoffset
                     end
                 elseif leftkern ~= 0 or rightkern ~= 0 then
-                    p.injections = {
+                    p[injection] = {
                         leftkern  = leftkern,
                         rightkern = rightkern,
                         yoffset   = yoffset,
                     }
                 else
-                    p.injections = {
+                    p[injection] = {
                         yoffset = yoffset,
                     }
                 end
             elseif leftkern ~= 0 or rightkern ~= 0 then
                 properties[current] = {
-                    injections = {
+                    [injection] = {
                         leftkern  = leftkern,
                         rightkern = rightkern,
                         yoffset   = yoffset,
@@ -239,7 +254,7 @@ function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2l
                 }
             else
                 properties[current] = {
-                    injections = {
+                    [injection] = {
                         yoffset = yoffset,
                     },
                 }
@@ -250,10 +265,9 @@ function injections.setpair(current,factor,rlmode,r2lflag,spec,injection) -- r2l
     return x, y, w, h -- no bound
 end
 
--- this needs checking for rl < 0 but it is unlikely that a r2l script
--- uses kernclasses between glyphs so we're probably safe (KE has a
--- problematic font where marks interfere with rl < 0 in the previous
--- case)
+-- This needs checking for rl < 0 but it is unlikely that a r2l script uses kernclasses between
+-- glyphs so we're probably safe (KE has a problematic font where marks interfere with rl < 0 in
+-- the previous case)
 
 function injections.setkern(current,factor,rlmode,x,injection)
     local dx = factor * x
@@ -285,7 +299,7 @@ function injections.setkern(current,factor,rlmode,x,injection)
     end
 end
 
-function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase) -- ba=baseanchor, ma=markanchor
+function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase,mkmk) -- ba=baseanchor, ma=markanchor
     local dx, dy = factor*(ba[1]-ma[1]), factor*(ba[2]-ma[2])
     nofregisteredmarks = nofregisteredmarks + 1
  -- markanchors[nofregisteredmarks] = base
@@ -293,14 +307,20 @@ function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase) -- ba=basean
         dx = tfmbase.width - dx -- see later commented ox
     end
     local p = rawget(properties,start)
+    -- hm, dejavu serif does a sloppy mark2mark before mark2base
     if p then
         local i = rawget(p,"injections")
         if i then
-            i.markx        = dx
-            i.marky        = dy
-            i.markdir      = rlmode or 0
-            i.markbase     = nofregisteredmarks
-            i.markbasenode = base
+            if i.markmark then
+                -- out of order mkmk: yes or no or option
+            else
+                i.markx        = dx
+                i.marky        = dy
+                i.markdir      = rlmode or 0
+                i.markbase     = nofregisteredmarks
+                i.markbasenode = base
+                i.markmark     = mkmk
+            end
         else
             p.injections = {
                 markx        = dx,
@@ -308,6 +328,7 @@ function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase) -- ba=basean
                 markdir      = rlmode or 0,
                 markbase     = nofregisteredmarks,
                 markbasenode = base,
+                markmark     = mkmk,
             }
         end
     else
@@ -318,6 +339,7 @@ function injections.setmark(start,base,factor,rlmode,ba,ma,tfmbase) -- ba=basean
                 markdir      = rlmode or 0,
                 markbase     = nofregisteredmarks,
                 markbasenode = base,
+                markmark     = mkmk,
             },
         }
     end
@@ -430,30 +452,36 @@ local function show_result(head)
     end
 end
 
--- we could also check for marks here but maybe not all are registered (needs checking)
-
-local function collect_glyphs_1(head)
-    local glyphs, nofglyphs = { }, 0
-    local marks, nofmarks = { }, 0
+local function collect_glyphs(head,offsets)
+    local glyphs, glyphi, nofglyphs = { }, { }, 0
+    local marks, marki, nofmarks = { }, { }, 0
     local nf, tm = nil, nil
-    for n in traverse_id(glyph_code,head) do -- only needed for relevant fonts
-        if getsubtype(n) < 256 then
-            local f = getfont(n)
-            if f ~= nf then
-                nf = f
-                tm = fontdata[nf].resources.marks -- other hash in ctx
-            end
-            if tm and tm[getchar(n)] then
-                nofmarks = nofmarks + 1
-                marks[nofmarks] = n
-            else
-                nofglyphs = nofglyphs + 1
-                glyphs[nofglyphs] = n
+    local n = head
+
+    local function identify(n,what)
+        local f = getfont(n)
+        if f ~= nf then
+            nf = f
+            -- other hash in ctx:
+            tm = fontdata[nf].resources
+            if tm then
+                tm = tm.marks
             end
+        end
+        if tm and tm[getchar(n)] then
+            nofmarks = nofmarks + 1
+            marks[nofmarks] = n
+            marki[nofmarks] = "injections"
+        else
+            nofglyphs = nofglyphs + 1
+            glyphs[nofglyphs] = n
+            glyphi[nofglyphs] = what
+        end
+        if offsets then
             -- yoffsets can influence curs steps
             local p = rawget(properties,n)
             if p then
-                local i = rawget(p,"injections")
+                local i = rawget(p,what)
                 if i then
                     local yoffset = i.yoffset
                     if yoffset and yoffset ~= 0 then
@@ -463,38 +491,50 @@ local function collect_glyphs_1(head)
             end
         end
     end
-    return glyphs, nofglyphs, marks, nofmarks
-end
 
-local function collect_glyphs_2(head)
-    local glyphs, nofglyphs = { }, 0
-    local marks, nofmarks = { }, 0
-    local nf, tm = nil, nil
-    for n in traverse_id(glyph_code,head) do
-        if getsubtype(n) < 256 then
-            local f = getfont(n)
-            if f ~= nf then
-                nf = f
-                tm = fontdata[nf].resources.marks -- other hash in ctx
-            end
-            if tm and tm[getchar(n)] then
-                nofmarks = nofmarks + 1
-                marks[nofmarks] = n
-            else
-                nofglyphs = nofglyphs + 1
-                glyphs[nofglyphs] = n
-            end
+    while n do -- only needed for relevant fonts
+        local id = getid(n)
+        if id == glyph_code then
+            identify(n,"injections")
+        elseif id == disc_code then
+            local d = getfield(n,"pre")
+            if d then
+                for n in traverse_id(glyph_code,d) do
+                    if getsubtype(n) < 256 then
+                        identify(n,"preinjections")
+                    end
+                end
+			end
+            local d = getfield(n,"post")
+            if d then
+                for n in traverse_id(glyph_code,d) do
+                    if getsubtype(n) < 256 then
+                        identify(n,"postinjections")
+                    end
+                end
+			end
+            local d = getfield(n,"replace")
+            if d then
+                for n in traverse_id(glyph_code,d) do
+                    if getsubtype(n) < 256 then
+                        identify(n,"replaceinjections")
+                    end
+                end
+			end
         end
+		n = getnext(n)
     end
-    return glyphs, nofglyphs, marks, nofmarks
+
+    return glyphs, glyphi, nofglyphs, marks, marki, nofmarks
 end
 
-local function inject_marks(marks,nofmarks)
+local function inject_marks(marks,marki,nofmarks)
     for i=1,nofmarks do
-        local n = marks[i]
+        local n  = marks[i]
         local pn = rawget(properties,n)
         if pn then
-            pn = rawget(pn,"injections")
+            local ni = marki[i]
+            local pn = rawget(pn,ni)
             if pn then
                 local p = pn.markbasenode
                 if p then
@@ -503,7 +543,7 @@ local function inject_marks(marks,nofmarks)
                     local rightkern = nil
                     local pp = rawget(properties,p)
                     if pp then
-                        pp = rawget(pp,"injections")
+                        pp = rawget(pp,ni)
                         if pp then
                             rightkern = pp.rightkern
                         end
@@ -516,13 +556,22 @@ local function inject_marks(marks,nofmarks)
                         else
                             -- kern(x) glyph(p) kern(w-x) mark(n)
                          -- ox = px - getfield(p,"width") + pn.markx - pp.leftkern
-                            local leftkern = pp.leftkern
-                            if leftkern then
-                                ox = px - pn.markx
+                            --
+							-- According to Kai we don't need to handle leftkern here but I'm
+                            -- pretty sure I've run into a case where it was needed so maybe
+	                        -- some day we need something more clever here.
+                            --
+							if false then
+                                -- a mark with kerning
+                                local leftkern = pp.leftkern
+                                if leftkern then
+                                    ox = px - pn.markx - leftkern
+                                else
+                                    ox = px - pn.markx
+                                end
                             else
-                                ox = px - pn.markx - leftkern
+                                ox = px - pn.markx
                             end
--- report_injections("l2r case 1: %p",ox)
                         end
                     else
                         -- we need to deal with fonts that have marks with width
@@ -548,12 +597,13 @@ local function inject_marks(marks,nofmarks)
                     setfield(n,"xoffset",ox)
                     --
                     local py = getfield(p,"yoffset")
-                    local oy = 0
-                    if marks[p] then
-                        oy = py + pn.marky
-                    else
-                        oy = getfield(n,"yoffset") + py + pn.marky
-                    end
+--                     local oy = 0
+--                     if marks[p] then
+--                         oy = py + pn.marky
+--                     else
+--                         oy = getfield(n,"yoffset") + py + pn.marky
+--                     end
+                    local oy = getfield(n,"yoffset") + py + pn.marky
                     setfield(n,"yoffset",oy)
                 else
                     -- normally this can't happen (only when in trace mode which is a special case anyway)
@@ -564,14 +614,14 @@ local function inject_marks(marks,nofmarks)
     end
 end
 
-local function inject_cursives(glyphs,nofglyphs)
+local function inject_cursives(glyphs,glyphi,nofglyphs)
     local cursiveanchor, lastanchor = nil, nil
     local minc, maxc, last = 0, 0, nil
     for i=1,nofglyphs do
-        local n = glyphs[i]
+        local n  = glyphs[i]
         local pn = rawget(properties,n)
         if pn then
-            pn = rawget(pn,"injections")
+            pn = rawget(pn,glyphi[i])
         end
         if pn then
             local cursivex = pn.cursivex
@@ -630,7 +680,7 @@ local function inject_cursives(glyphs,nofglyphs)
      -- if maxc > 0 and not cursiveanchor then
      --     local ny = getfield(n,"yoffset")
      --     for i=maxc,minc,-1 do
-     --         local ti = glyphs[i]
+     --         local ti = glyphs[i][1]
      --         ny = ny + properties[ti].cursivedy
      --         setfield(ti,"yoffset",ny) -- why not add ?
      --     end
@@ -647,23 +697,67 @@ local function inject_cursives(glyphs,nofglyphs)
     end
 end
 
-local function inject_kerns(head,list,length)
- -- todo: pre/post/replace
+-- G  +D-pre        G
+--     D-post+
+--    +D-replace+
+--
+-- G  +D-pre       +D-pre
+--     D-post      +D-post
+--    +D-replace   +D-replace
+
+local function inject_kerns(head,glist,ilist,length) -- not complete ! compare with inject_kerns_only (but unlikely disc here)
     for i=1,length do
-        local n  = list[i]
+        local n  = glist[i]
         local pn = rawget(properties,n)
         if pn then
-            local i = rawget(pn,"injections")
-            if i then
-                local leftkern = i.leftkern
-                if leftkern and leftkern ~= 0 then
-                    insert_node_before(head,n,newkern(leftkern)) -- type 0/2
-                end
-                local rightkern = i.rightkern
-                if rightkern and rightkern ~= 0 then
-                    insert_node_after(head,n,newkern(rightkern)) -- type 0/2
-                end
-            end
+			local dp = nil
+			local dr = nil
+            local ni = ilist[i]
+            local p  = nil
+			if ni == "injections" then
+				p = getprev(n)
+				if p then
+					local id = getid(p)
+					if id == disc_code then
+						dp = getfield(p,"post")
+						dr = getfield(p,"replace")
+					end
+				end
+			end
+			if dp then
+				local i = rawget(pn,"postinjections")
+				if i then
+					local leftkern = i.leftkern
+					if leftkern and leftkern ~= 0 then
+						local t = find_tail(dp)
+						insert_node_after(dp,t,newkern(leftkern))
+                        setfield(p,"post",dp) -- currently we need to force a tail refresh
+					end
+				end
+			end
+			if dr then
+				local i = rawget(pn,"replaceinjections")
+				if i then
+					local leftkern = i.leftkern
+					if leftkern and leftkern ~= 0 then
+						local t = find_tail(dr)
+						insert_node_after(dr,t,newkern(leftkern))
+                        setfield(p,"replace",dr) -- currently we need to force a tail refresh
+					end
+				end
+			else
+				local i = rawget(pn,ni)
+				if i then
+					local leftkern = i.leftkern
+					if leftkern and leftkern ~= 0 then
+						insert_node_before(head,n,newkern(leftkern)) -- type 0/2
+					end
+					local rightkern = i.rightkern
+					if rightkern and rightkern ~= 0 then
+						insert_node_after(head,n,newkern(rightkern)) -- type 0/2
+					end
+				end
+			end
         end
     end
 end
@@ -673,23 +767,18 @@ local function inject_everything(head,where)
     if trace_injections then
         trace(head,"everything")
     end
-    local glyphs, nofglyphs, marks, nofmarks
-    if nofregisteredpairs > 0 then
-        glyphs, nofglyphs, marks, nofmarks = collect_glyphs_1(head)
-    else
-        glyphs, nofglyphs, marks, nofmarks = collect_glyphs_2(head)
-    end
+    local glyphs, glyphi, nofglyphs, marks, marki, nofmarks = collect_glyphs(head,nofregisteredpairs > 0)
     if nofglyphs > 0 then
         if nofregisteredcursives > 0 then
-            inject_cursives(glyphs,nofglyphs)
+            inject_cursives(glyphs,glyphi,nofglyphs)
         end
         if nofregisteredmarks > 0 then -- and nofmarks > 0
-            inject_marks(marks,nofmarks)
+            inject_marks(marks,marki,nofmarks)
         end
-        inject_kerns(head,glyphs,nofglyphs)
+        inject_kerns(head,glyphs,glyphi,nofglyphs)
     end
     if nofmarks > 0 then
-        inject_kerns(head,marks,nofmarks)
+        inject_kerns(head,marks,marki,nofmarks)
 	end
     if keepregisteredcounts then
         keepregisteredcounts  = false
@@ -702,13 +791,21 @@ local function inject_everything(head,where)
     return tonode(head), true
 end
 
+-- G  +D-pre        G
+--     D-post+
+--    +D-replace+
+--
+-- G  +D-pre       +D-pre
+--     D-post      +D-post
+--    +D-replace   +D-replace
+
 local function inject_kerns_only(head,where)
     head = tonut(head)
     if trace_injections then
         trace(head,"kerns")
     end
     local n = head
-    local p = nil
+    local p = nil -- disc node when non-nil
     while n do
         local id = getid(n)
         if id == glyph_code then
@@ -724,6 +821,7 @@ local function inject_kerns_only(head,where)
                                 if leftkern and leftkern ~= 0 then
                                     local t = find_tail(d)
                                     insert_node_after(d,t,newkern(leftkern))
+                                    setfield(p,"post",d) -- currently we need to force a tail refresh
                                 end
                             end
                         end
@@ -735,6 +833,7 @@ local function inject_kerns_only(head,where)
                                 if leftkern and leftkern ~= 0 then
                                     local t = find_tail(d)
                                     insert_node_after(d,t,newkern(leftkern))
+                                    setfield(p,"replace",d) -- currently we need to force a tail refresh
                                 end
                             end
                         else
@@ -747,6 +846,7 @@ local function inject_kerns_only(head,where)
                             end
                         end
                     else
+                        -- this is the most common case
                         local i = rawget(pn,"injections")
                         if i then
                             local leftkern = i.leftkern
@@ -756,8 +856,6 @@ local function inject_kerns_only(head,where)
                         end
                     end
                 end
-            else
-                break
             end
             p = nil
         elseif id == disc_code then
@@ -812,7 +910,7 @@ local function inject_kerns_only(head,where)
                 local h = d
                 for n in traverse_id(glyph_code,d) do
                     if getsubtype(n) < 256 then
-                        local pn = rawget(properties,n) -- why can it be empty { }
+                        local pn = rawget(properties,n)
                         if pn then
                             local i = rawget(pn,"replaceinjections")
                             if i then
@@ -850,9 +948,8 @@ local function inject_pairs_only(head,where)
     if trace_injections then
         trace(head,"pairs")
     end
-    --
     local n = head
-    local p = nil
+    local p = nil -- disc node when non-nil
     while n do
         local id = getid(n)
         if id == glyph_code then
@@ -868,6 +965,7 @@ local function inject_pairs_only(head,where)
                                 if leftkern and leftkern ~= 0 then
                                     local t = find_tail(d)
                                     insert_node_after(d,t,newkern(leftkern))
+                                    setfield(p,"post",d) -- currently we need to force a tail refresh
                                 end
                              -- local rightkern = i.rightkern
                              -- if rightkern and rightkern ~= 0 then
@@ -884,6 +982,7 @@ local function inject_pairs_only(head,where)
                                 if leftkern and leftkern ~= 0 then
                                     local t = find_tail(d)
                                     insert_node_after(d,t,newkern(leftkern))
+                                    setfield(p,"replace",d) -- currently we need to force a tail refresh
                                 end
                              -- local rightkern = i.rightkern
                              -- if rightkern and rightkern ~= 0 then
@@ -909,24 +1008,22 @@ local function inject_pairs_only(head,where)
                         -- this is the most common case
                         local i = rawget(pn,"injections")
                         if i then
-                            local yoffset = i.yoffset
-                            if yoffset and yoffset ~= 0 then
-                                setfield(n,"yoffset",yoffset)
-                            end
                             local leftkern = i.leftkern
                             if leftkern and leftkern ~= 0 then
-                                insert_node_before(head,n,newkern(leftkern))
+                                head = insert_node_before(head,n,newkern(leftkern))
                             end
                             local rightkern = i.rightkern
                             if rightkern and rightkern ~= 0 then
                                 insert_node_after(head,n,newkern(rightkern))
                                 n = getnext(n) -- to be checked
                             end
+                            local yoffset = i.yoffset
+                            if yoffset and yoffset ~= 0 then
+                                setfield(n,"yoffset",yoffset)
+                            end
                         end
                     end
                 end
-            else
-                break
             end
             p = nil
         elseif id == disc_code then
@@ -935,16 +1032,12 @@ local function inject_pairs_only(head,where)
                 local h = d
                 for n in traverse_id(glyph_code,d) do
                     if getsubtype(n) < 256 then
-                        local p = rawget(properties,n)
-                        if p then
-                            local i = rawget(p,"preinjections")
+                        local pn = rawget(properties,n)
+                        if pn then
+                            local i = rawget(pn,"preinjections")
                             if i then
-                                local yoffset = i.yoffset
-                                if yoffset and yoffset ~= 0 then
-                                    setfield(n,"yoffset",yoffset)
-                                end
                                 local leftkern = i.leftkern
-                                if leftkern ~= 0 then
+                                if leftkern and leftkern ~= 0 then
                                     h = insert_node_before(h,n,newkern(leftkern))
                                 end
                                 local rightkern = i.rightkern
@@ -952,6 +1045,10 @@ local function inject_pairs_only(head,where)
                                     insert_node_after(head,n,newkern(rightkern))
                                     n = getnext(n) -- to be checked
                                 end
+                                local yoffset = i.yoffset
+                                if yoffset and yoffset ~= 0 then
+                                    setfield(n,"yoffset",yoffset)
+                                end
                             end
                         end
                     else
@@ -967,14 +1064,10 @@ local function inject_pairs_only(head,where)
                 local h = d
                 for n in traverse_id(glyph_code,d) do
                     if getsubtype(n) < 256 then
-                        local p = rawget(properties,n)
-                        if p then
-                            local i = rawget(p,"postinjections")
+                        local pn = rawget(properties,n)
+                        if pn then
+                            local i = rawget(pn,"postinjections")
                             if i then
-                                local yoffset = i.yoffset
-                                if yoffset and yoffset ~= 0 then
-                                    setfield(n,"yoffset",yoffset)
-                                end
                                 local leftkern = i.leftkern
                                 if leftkern and leftkern ~= 0 then
                                     h = insert_node_before(h,n,newkern(leftkern))
@@ -984,6 +1077,10 @@ local function inject_pairs_only(head,where)
                                     insert_node_after(head,n,newkern(rightkern))
                                     n = getnext(n) -- to be checked
                                 end
+                                local yoffset = i.yoffset
+                                if yoffset and yoffset ~= 0 then
+                                    setfield(n,"yoffset",yoffset)
+                                end
                             end
                         end
                     else
@@ -999,14 +1096,10 @@ local function inject_pairs_only(head,where)
                 local h = d
                 for n in traverse_id(glyph_code,d) do
                     if getsubtype(n) < 256 then
-                        local p = rawget(properties,n)
-                        if p then
-                            local i = rawget(p,"replaceinjections")
+                        local pn = rawget(properties,n)
+                        if pn then
+                            local i = rawget(pn,"replaceinjections")
                             if i then
-                                local yoffset = i.yoffset
-                                if yoffset and yoffset ~= 0 then
-                                    setfield(n,"yoffset",yoffset)
-                                end
                                 local leftkern = i.leftkern
                                 if leftkern and leftkern ~= 0 then
                                     h = insert_node_before(h,n,newkern(leftkern))
@@ -1016,6 +1109,10 @@ local function inject_pairs_only(head,where)
                                     insert_node_after(head,n,newkern(rightkern))
                                     n = getnext(n) -- to be checked
                                 end
+                                local yoffset = i.yoffset
+                                if yoffset and yoffset ~= 0 then
+                                    setfield(n,"yoffset",yoffset)
+                                end
                             end
                         end
                     else
@@ -1042,7 +1139,7 @@ local function inject_pairs_only(head,where)
     return tonode(head), true
 end
 
-function injections.handler(head,where) -- optimize for n=1 ?
+function injections.handler(head,where)
     if nofregisteredmarks > 0 or nofregisteredcursives > 0 then
         return inject_everything(head,where)
     elseif nofregisteredpairs > 0 then