Merge pull request #345 from phi-gamma/master

first batch of fixes

12 files changed, 580 insertions, 169 deletions

diff --git a/src/fontloader/misc/fontloader-font-afm.lua b/src/fontloader/misc/fontloader-font-afm.lua
index 329639b..99b8577 100644
--- a/src/fontloader/misc/fontloader-font-afm.lua
+++ b/src/fontloader/misc/fontloader-font-afm.lua
@@ -28,9 +28,11 @@ don't have this issue.</p>
 local fonts, logs, trackers, containers, resolvers = fonts, logs, trackers, containers, resolvers
 
 local next, type, tonumber = next, type, tonumber
-local format, match, gmatch, lower, gsub, strip = string.format, string.match, string.gmatch, string.lower, string.gsub, string.strip
+local match, gmatch, lower, gsub, strip, find = string.match, string.gmatch, string.lower, string.gsub, string.strip, string.find
+local char, byte, sub = string.char, string.byte, string.sub
 local abs = math.abs
-local P, S, C, R, lpegmatch, patterns = lpeg.P, lpeg.S, lpeg.C, lpeg.R, lpeg.match, lpeg.patterns
+local bxor, rshift = bit32.bxor, bit32.rshift
+local P, S, R, Cmt, C, Ct, Cs, lpegmatch, patterns = lpeg.P, lpeg.S, lpeg.R, lpeg.Cmt, lpeg.C, lpeg.Ct, lpeg.Cs, lpeg.match, lpeg.patterns
 local derivetable = table.derive
 
 local trace_features     = false  trackers.register("afm.features",   function(v) trace_features = v end)
@@ -48,18 +50,13 @@ local definers           = fonts.definers
 local readers            = fonts.readers
 local constructors       = fonts.constructors
 
-local fontloader         = fontloader
-local font_to_table      = fontloader.to_table
-local open_font          = fontloader.open
-local close_font         = fontloader.close
-
 local afm                = constructors.newhandler("afm")
 local pfb                = constructors.newhandler("pfb")
 
 local afmfeatures        = constructors.newfeatures("afm")
 local registerafmfeature = afmfeatures.register
 
-afm.version              = 1.500 -- incrementing this number one up will force a re-cache
+afm.version              = 1.501 -- incrementing this number one up will force a re-cache
 afm.cache                = containers.define("fonts", "afm", afm.version, true)
 afm.autoprefixed         = true -- this will become false some day (catches texnansi-blabla.*)
 
@@ -171,7 +168,7 @@ end
 local function get_charmetrics(data,charmetrics,vector)
     local characters = data.characters
     local chr, ind = { }, 0
-    for k,v in gmatch(charmetrics,"([%a]+) +(.-) *;") do
+    for k, v in gmatch(charmetrics,"([%a]+) +(.-) *;") do
         if k == 'C'  then
             v = tonumber(v)
             if v < 0 then
@@ -225,41 +222,193 @@ local function get_variables(data,fontmetrics)
     end
 end
 
-local function get_indexes(data,pfbname)
-    data.resources.filename = resolvers.unresolve(pfbname) -- no shortcut
-    local pfbblob = open_font(pfbname)
-    if pfbblob then
-        local characters = data.characters
-        local pfbdata = font_to_table(pfbblob)
-        if pfbdata then
-            local glyphs = pfbdata.glyphs
-            if glyphs then
-                if trace_loading then
-                    report_afm("getting index data from %a",pfbname)
-                end
-                for index, glyph in next, glyphs do
-            --  for index, glyph in table.sortedhash(glyphs) do
-                    local name = glyph.name
-                    if name then
-                        local char = characters[name]
-                        if char then
-                            if trace_indexing then
-                                report_afm("glyph %a has index %a",name,index)
+local get_indexes
+
+do
+
+    -- old font loader
+
+    local fontloader = fontloader
+
+    if fontloader then
+
+        local font_to_table = fontloader.to_table
+        local open_font     = fontloader.open
+        local close_font    = fontloader.close
+
+        local function get_indexes_old(data,pfbname)
+            local pfbblob = open_font(pfbname)
+            if pfbblob then
+                local characters = data.characters
+                local pfbdata = font_to_table(pfbblob)
+                if pfbdata then
+                    local glyphs = pfbdata.glyphs
+                    if glyphs then
+                        if trace_loading then
+                            report_afm("getting index data from %a",pfbname)
+                        end
+                        for index, glyph in next, glyphs do
+                            local name = glyph.name
+                            if name then
+                                local char = characters[name]
+                                if char then
+                                    if trace_indexing then
+                                        report_afm("glyph %a has index %a",name,index)
+                                    end
+                                    char.index = index
+                                end
                             end
-                            char.index = index
                         end
+                    elseif trace_loading then
+                        report_afm("no glyph data in pfb file %a",pfbname)
                     end
+                elseif trace_loading then
+                    report_afm("no data in pfb file %a",pfbname)
                 end
+                close_font(pfbblob)
             elseif trace_loading then
-                report_afm("no glyph data in pfb file %a",pfbname)
+                report_afm("invalid pfb file %a",pfbname)
             end
-        elseif trace_loading then
-            report_afm("no data in pfb file %a",pfbname)
         end
-        close_font(pfbblob)
-    elseif trace_loading then
-        report_afm("invalid pfb file %a",pfbname)
+
     end
+
+    -- new (unfinished) font loader but i see no differences between
+    -- old and new (one bad vector with old)
+
+    local n, m
+
+    local progress = function(str,position,name,size)
+        local forward = position + tonumber(size) + 3 + 2
+        n = n + 1
+        if n >= m then
+            return #str, name
+        elseif forward < #str then
+            return forward, name
+        else
+            return #str, name
+        end
+    end
+
+    local initialize = function(str,position,size)
+        n = 0
+        m = tonumber(size)
+        return position + 1
+    end
+
+    local charstrings = P("/CharStrings")
+    local name        = P("/") * C((R("az")+R("AZ")+R("09")+S("-_."))^1)
+    local size        = C(R("09")^1)
+    local spaces      = P(" ")^1
+
+    local p_filternames = Ct (
+        (1-charstrings)^0 * charstrings * spaces * Cmt(size,initialize)
+      * (Cmt(name * P(" ")^1 * C(R("09")^1), progress) + P(1))^1
+    )
+
+    -- if one of first 4 not 0-9A-F then binary else hex
+
+    local decrypt
+
+    do
+
+        local r, c1, c2, n = 0, 0, 0, 0
+
+        local function step(c)
+            local cipher = byte(c)
+            local plain  = bxor(cipher,rshift(r,8))
+            r = ((cipher + r) * c1 + c2) % 65536
+            return char(plain)
+        end
+
+        decrypt = function(binary)
+            r, c1, c2, n = 55665, 52845, 22719, 4
+            binary       = gsub(binary,".",step)
+            return sub(binary,n+1)
+        end
+
+     -- local pattern = Cs((P(1) / step)^1)
+     --
+     -- decrypt = function(binary)
+     --     r, c1, c2, n = 55665, 52845, 22719, 4
+     --     binary = lpegmatch(pattern,binary)
+     --     return sub(binary,n+1)
+     -- end
+
+    end
+
+    local function loadpfbvector(filename)
+        -- for the moment limited to encoding only
+
+        local data = io.loaddata(resolvers.findfile(filename))
+
+        if not find(data,"!PS%-AdobeFont%-") then
+            print("no font",filename)
+            return
+        end
+
+        if not data then
+            print("no data",filename)
+            return
+        end
+
+        local ascii, binary = match(data,"(.*)eexec%s+......(.*)")
+
+        if not binary then
+            print("no binary",filename)
+            return
+        end
+
+        binary = decrypt(binary,4)
+
+        local vector = lpegmatch(p_filternames,binary)
+
+        vector[0] = table.remove(vector,1)
+
+        if not vector then
+            print("no vector",filename)
+            return
+        end
+
+        return vector
+
+    end
+
+    get_indexes = function(data,pfbname)
+        local vector = loadpfbvector(pfbname)
+        if vector then
+            local characters = data.characters
+            if trace_loading then
+                report_afm("getting index data from %a",pfbname)
+            end
+            for index=1,#vector do
+                local name = vector[index]
+                local char = characters[name]
+                if char then
+                    if trace_indexing then
+                        report_afm("glyph %a has index %a",name,index)
+                    end
+                    char.index = index
+                end
+            end
+        end
+    end
+
+    if fontloader then
+
+        afm.use_new_indexer = true
+        get_indexes_new     = get_indexes
+
+        get_indexes = function(data,pfbname)
+            if afm.use_new_indexer then
+                return get_indexes_new(data,pfbname)
+            else
+                return get_indexes_old(data,pfbname)
+            end
+        end
+
+    end
+
 end
 
 local function readafm(filename)
@@ -351,8 +500,9 @@ function afm.load(filename)
             data = readafm(filename)
             if data then
                 if pfbname ~= "" then
+                    data.resources.filename = resolvers.unresolve(pfbname)
                     get_indexes(data,pfbname)
-                elseif trace_loading then
+               elseif trace_loading then
                     report_afm("no pfb file for %a",filename)
                  -- data.resources.filename = "unset" -- better than loading the afm file
                 end
@@ -397,9 +547,10 @@ local uparser = fonts.mappings.makenameparser()
 
 unify = function(data, filename)
     local unicodevector = fonts.encodings.agl.unicodes -- loaded runtime in context
-    local unicodes, names = { }, { }
-    local private = constructors.privateoffset
-    local descriptions = data.descriptions
+    local unicodes      = { }
+    local names         = { }
+    local private       = constructors.privateoffset
+    local descriptions  = data.descriptions
     for name, blob in next, data.characters do
         local code = unicodevector[name] -- or characters.name_to_unicode[name]
         if not code then
diff --git a/src/fontloader/misc/fontloader-font-con.lua b/src/fontloader/misc/fontloader-font-con.lua
index f36f750..b118535 100644
--- a/src/fontloader/misc/fontloader-font-con.lua
+++ b/src/fontloader/misc/fontloader-font-con.lua
@@ -776,9 +776,14 @@ function constructors.scale(tfmdata,specification)
         elseif autoitalicamount then -- itlc feature
             local vi = description.italic
             if not vi then
-                local vi = description.boundingbox[3] - description.width + autoitalicamount
-                if vi > 0 then -- < 0 indicates no overshoot or a very small auto italic
-                    chr.italic = vi*hdelta
+                local bb = description.boundingbox
+                if bb then
+                    local vi = bb[3] - description.width + autoitalicamount
+                    if vi > 0 then -- < 0 indicates no overshoot or a very small auto italic
+                        chr.italic = vi*hdelta
+                    end
+                else
+                 -- report_defining("no boundingbox for character %C in font %a, fullname %a, filename %a",unicode,name,fullname,filename)
                 end
             elseif vi ~= 0 then
                 chr.italic = vi*hdelta
diff --git a/src/fontloader/misc/fontloader-font-dsp.lua b/src/fontloader/misc/fontloader-font-dsp.lua
index 14e816d..85a80bd 100644
--- a/src/fontloader/misc/fontloader-font-dsp.lua
+++ b/src/fontloader/misc/fontloader-font-dsp.lua
@@ -525,7 +525,7 @@ local function chainedcontext(f,fontdata,lookupid,lookupoffset,offset,glyphs,nof
                             end
                         end
                         local noflookups = readushort(f)
-                        local lookups = { }
+                        local lookups    = { }
                         for i=1,noflookups do
                             lookups[readushort(f)+1] = readushort(f) + 1
                         end
diff --git a/src/fontloader/misc/fontloader-font-map.lua b/src/fontloader/misc/fontloader-font-map.lua
index db501f0..509e751 100644
--- a/src/fontloader/misc/fontloader-font-map.lua
+++ b/src/fontloader/misc/fontloader-font-map.lua
@@ -19,6 +19,8 @@ local trace_mapping = false  trackers.register("fonts.mapping", function(v) trac
 
 local report_fonts  = logs.reporter("fonts","loading") -- not otf only
 
+local force_ligatures = false  directives.register("fonts.mapping.forceligatures",function(v) force_ligatures = v end)
+
 local fonts         = fonts or { }
 local mappings      = fonts.mappings or { }
 fonts.mappings      = mappings
@@ -443,7 +445,7 @@ function mappings.addtounicode(data,filename,checklookups)
     local collected = false
     local unicoded  = 0
     for unicode, glyph in next, descriptions do
-        if not glyph.unicode and glyph.class == "ligature" then
+        if glyph.class == "ligature" and (force_ligatures or not glyph.unicode) then
             if not collected then
                 collected = fonts.handlers.otf.readers.getcomponents(data)
                 if not collected then
diff --git a/src/fontloader/misc/fontloader-font-otj.lua b/src/fontloader/misc/fontloader-font-otj.lua
index aae70d1..ebda723 100644
--- a/src/fontloader/misc/fontloader-font-otj.lua
+++ b/src/fontloader/misc/fontloader-font-otj.lua
@@ -49,8 +49,8 @@ local attributes, nodes, node = attributes, nodes, node
 fonts                    = fonts
 local hashes             = fonts.hashes
 local fontdata           = hashes.identifiers
-local parameters         = fonts.hashes.parameters
-local resources          = fonts.hashes.resources
+----- parameters         = fonts.hashes.parameters -- not in generic
+----- resources          = fonts.hashes.resources  -- not in generic
 
 nodes.injections         = nodes.injections or { }
 local injections         = nodes.injections
@@ -1444,7 +1444,7 @@ local function injectspaces(head)
      -- end
         leftkerns  = trig.left
         rightkerns = trig.right
-        local par  = parameters[font]
+        local par  = fontdata[font].parameters -- fallback for generic
         factor     = par.factor
         threshold  = par.spacing.width - 1 -- get rid of rounding errors
         lastfont   = font
diff --git a/src/fontloader/misc/fontloader-font-otl.lua b/src/fontloader/misc/fontloader-font-otl.lua
index 210abfe..bcea275 100644
--- a/src/fontloader/misc/fontloader-font-otl.lua
+++ b/src/fontloader/misc/fontloader-font-otl.lua
@@ -53,7 +53,7 @@ local report_otf         = logs.reporter("fonts","otf loading")
 local fonts              = fonts
 local otf                = fonts.handlers.otf
 
-otf.version              = 3.017 -- beware: also sync font-mis.lua and in mtx-fonts
+otf.version              = 3.018 -- beware: also sync font-mis.lua and in mtx-fonts
 otf.cache                = containers.define("fonts", "otl", otf.version, true)
 
 local otfreaders         = otf.readers
diff --git a/src/fontloader/misc/fontloader-font-otr.lua b/src/fontloader/misc/fontloader-font-otr.lua
index 3542d18..24f6854 100644
--- a/src/fontloader/misc/fontloader-font-otr.lua
+++ b/src/fontloader/misc/fontloader-font-otr.lua
@@ -60,16 +60,16 @@ if not modules then modules = { } end modules ['font-otr'] = {
 -- faster but it might not be the real bottleneck as we still need to juggle data. It
 -- is probably more memory efficient as no intermediate strings are involved.
 
-if not characters then
-    require("char-def")
-    require("char-ini")
-end
+-- if not characters then
+--     require("char-def")
+--     require("char-ini")
+-- end
 
 local next, type, unpack = next, type, unpack
 local byte, lower, char, strip, gsub = string.byte, string.lower, string.char, string.strip, string.gsub
 local bittest = bit32.btest
-local concat, remove, unpack = table.concat, table.remov, table.unpack
-local floor, mod, abs, sqrt, round = math.floor, math.mod, math.abs, math.sqrt, math.round
+local concat, remove, unpack, fastcopy = table.concat, table.remov, table.unpack, table.fastcopy
+local floor, abs, sqrt, round = math.floor, math.abs, math.sqrt, math.round
 local P, R, S, C, Cs, Cc, Ct, Carg, Cmt = lpeg.P, lpeg.R, lpeg.S, lpeg.C, lpeg.Cs, lpeg.Cc, lpeg.Ct, lpeg.Carg, lpeg.Cmt
 local lpegmatch = lpeg.match
 
@@ -1066,14 +1066,13 @@ readers.hmtx = function(f,fontdata,specification)
             local nofmetrics      = fontdata.horizontalheader.nofhmetrics
             local glyphs          = fontdata.glyphs
             local nofglyphs       = fontdata.nofglyphs
-            local nofrepeated     = nofglyphs - nofmetrics
             local width           = 0 -- advance
             local leftsidebearing = 0
             for i=0,nofmetrics-1 do
                 local glyph     = glyphs[i]
                 width           = readshort(f)
                 leftsidebearing = readshort(f)
-                if advance ~= 0 then
+                if width ~= 0 then
                     glyph.width = width
                 end
              -- if leftsidebearing ~= 0 then
@@ -1082,8 +1081,8 @@ readers.hmtx = function(f,fontdata,specification)
             end
             -- The next can happen in for instance a monospace font or in a cjk font
             -- with fixed widths.
-            for i=nofmetrics,nofrepeated do
-                local glyph     = glyphs[i]
+            for i=nofmetrics,nofglyphs-1 do
+                local glyph = glyphs[i]
                 if width ~= 0 then
                     glyph.width = width
                 end
@@ -1187,6 +1186,8 @@ local sequence = {
     { 3,  0,  6 },
     -- variants
     { 0,  5, 14 },
+    -- last resort ranges
+    { 3, 10, 13 },
 }
 
 -- local sequence = {
@@ -1269,10 +1270,10 @@ formatreaders[4] = function(f,fontdata,offset)
             -- bad encoding
         elseif offset == 0 then
             if trace_cmap then
-                report("format 4.%i segment %2i from %C upto %C at index %H",1,segment,startchar,endchar,mod(startchar + delta,65536))
+                report("format 4.%i segment %2i from %C upto %C at index %H",1,segment,startchar,endchar,(startchar + delta) % 65536)
             end
             for unicode=startchar,endchar do
-                local index = mod(unicode + delta,65536)
+                local index = (unicode + delta) % 65536
                 if index and index > 0 then
                     local glyph = glyphs[index]
                     if glyph then
@@ -1302,13 +1303,13 @@ formatreaders[4] = function(f,fontdata,offset)
         else
             local shift = (segment-nofsegments+offset/2) - startchar
             if trace_cmap then
-                report("format 4.%i segment %2i from %C upto %C at index %H",0,segment,startchar,endchar,mod(startchar + delta,65536))
+                report("format 4.%i segment %2i from %C upto %C at index %H",0,segment,startchar,endchar,(startchar + delta) % 65536)
             end
             for unicode=startchar,endchar do
                 local slot  = shift + unicode
                 local index = indices[slot]
                 if index and index > 0 then
-                    index = mod(index + delta,65536)
+                    index = (index + delta) % 65536
                     local glyph = glyphs[index]
                     if glyph then
                         local gu = glyph.unicode
@@ -1389,7 +1390,7 @@ formatreaders[12] = function(f,fontdata,offset)
         local last  = readulong(f)
         local index = readulong(f)
         if trace_cmap then
-            report("format 12 from %C to %C",first,last)
+            report("format 12 from %C to %C starts at index %i",first,last,index)
         end
         for unicode=first,last do
             local glyph = glyphs[index]
@@ -1417,6 +1418,53 @@ formatreaders[12] = function(f,fontdata,offset)
     return nofdone
 end
 
+formatreaders[13] = function(f,fontdata,offset)
+    --
+    -- this fector is only used for simple fallback fonts
+    --
+    setposition(f,offset+2+2+4+4) -- skip format reserved length language
+    local mapping    = fontdata.mapping
+    local glyphs     = fontdata.glyphs
+    local duplicates = fontdata.duplicates
+    local nofgroups  = readulong(f)
+    local nofdone    = 0
+    for i=1,nofgroups do
+        local first = readulong(f)
+        local last  = readulong(f)
+        local index = readulong(f)
+        if first < privateoffset then
+            if trace_cmap then
+                report("format 13 from %C to %C get index %i",first,last,index)
+            end
+            local glyph   = glyphs[index]
+            local unicode = glyph.unicode
+            if not unicode then
+                unicode = first
+                glyph.unicode = unicode
+                first = first + 1
+            end
+            local list     = duplicates[unicode]
+            mapping[index] = unicode
+            if not list then
+                list = { }
+                duplicates[unicode] = list
+            end
+            if last >= privateoffset then
+                local limit = privateoffset - 1
+                report("format 13 from %C to %C pruned to %C",first,last,limit)
+                last = limit
+            end
+            for unicode=first,last do
+                list[unicode] = true
+            end
+            nofdone = nofdone + last - first + 1
+        else
+            report("format 13 from %C to %C ignored",first,last)
+        end
+    end
+    return nofdone
+end
+
 formatreaders[14] = function(f,fontdata,offset)
     if offset and offset ~= 0 then
         setposition(f,offset)
@@ -2226,7 +2274,7 @@ function readers.extend(fontdata)
     end
 end
 
---
+-- for now .. this will move to a context specific file
 
 if fonts.hashes then
 
diff --git a/src/fontloader/misc/fontloader-font-ots.lua b/src/fontloader/misc/fontloader-font-ots.lua
index 6911872..90fcde2 100644
--- a/src/fontloader/misc/fontloader-font-ots.lua
+++ b/src/fontloader/misc/fontloader-font-ots.lua
@@ -9,6 +9,9 @@ if not modules then modules = { } end modules ['font-ots'] = { -- sequences
 -- to be checked: discrun doesn't seem to do something useful now (except run the
 -- check again) so if we need it again we'll do a zwnjrun or so
 
+-- components will go away and be replaced by a property table which simplifies
+-- code (also more efficient)
+
 -- beware, on my development machine we test a slightly a more optimized version
 
 -- assumptions:
@@ -566,7 +569,22 @@ local function toligature(head,start,stop,char,dataset,sequence,markflag,discfou
             local pre, post, replace, pretail, posttail, replacetail = getdisc(discfound,true)
             if not replace then -- todo: signal simple hyphen
                 local prev = getprev(base)
-                local copied = copy_node_list(comp)
+--                 local copied = copy_node_list(comp)
+local current  = comp
+local previous = nil
+local copied   = nil
+while current do
+    if getid(current) == glyph_code then
+        local n = copy_node(current)
+        if copied then
+            setlink(previous,n)
+        else
+            copied = n
+        end
+        previous = n
+    end
+    current = getnext(current)
+end
                 setprev(discnext,nil) -- also blocks funny assignments
                 setnext(discprev,nil) -- also blocks funny assignments
                 if pre then
@@ -2126,7 +2144,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                 else
                     local discfound = nil
                     local n = f + 1
-                    last = getnext(last)
+                    last = getnext(last) -- the second in current (first already matched)
                     while n <= l do
                         if not last and (sweeptype == "post" or sweeptype == "replace") then
                             last      = getnext(sweepnode)
@@ -2167,7 +2185,6 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                     end
                                     break
                                 end
-                                last = getnext(last)
                             elseif char == false then
                                 if discfound then
                                     notmatchreplace[discfound] = true
@@ -2220,6 +2237,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                     end
                                     match = not notmatchpre[last]
                                 end
+                                -- maybe only if match
                                 last = getnext(last)
                             else
                                 match = false
@@ -2255,8 +2273,12 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                             if trace_skips then
                                                 show_skip(dataset,sequence,char,ck,class)
                                             end
+                                            prev = getprev(prev) -- moved here
                                         elseif seq[n][char] then
-                                            n = n -1
+                                            if n > 1 then -- new test
+                                                prev = getprev(prev) -- moved here
+                                            end
+                                            n = n - 1
                                         else
                                             if discfound then
                                                 notmatchreplace[discfound] = true
@@ -2275,7 +2297,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                         end
                                         break
                                     end
-                                    prev = getprev(prev)
+                                 -- prev = getprev(prev) -- moved up
                                 elseif char == false then
                                     if discfound then
                                         notmatchreplace[discfound] = true
@@ -2339,21 +2361,20 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                             if not match then
                                                 break
                                             end
-                                        else
-                                            -- skip 'm
                                         end
-                                    else
-                                        -- skip 'm
                                     end
+                                    -- maybe only if match
+                                    prev = getprev(prev)
                                 elseif seq[n][32] then
                                     n = n - 1
+                                    prev = getprev(prev)
                                 else
                                     match = false
                                     break
                                 end
-                                prev = getprev(prev)
                             elseif seq[n][32] then -- somewhat special, as zapfino can have many preceding spaces
                                 n = n - 1
+                                prev = getprev(prev) -- was absent
                             else
                                 match = false
                                 break
@@ -2391,7 +2412,11 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                         if trace_skips then
                                             show_skip(dataset,sequence,char,ck,class)
                                         end
+                                        current = getnext(current) -- was absent
                                     elseif seq[n][char] then
+                                        if n < s then -- new test
+                                            current = getnext(current) -- was absent
+                                        end
                                         n = n + 1
                                     else
                                         if discfound then
@@ -2467,16 +2492,17 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                                 else
                                     -- skip 'm
                                 end
+                                -- maybe only if match
+                                current = getnext(current)
                             elseif seq[n][32] then -- brrr
                                 n = n + 1
                             else
                                 match = false
                                 break
                             end
-                            current = getnext(current)
                         elseif seq[n][32] then
                             n = n + 1
-current = getnext(current)
+                            current = getnext(current)
                         else
                             match = false
                             break
diff --git a/src/fontloader/misc/fontloader-font-oup.lua b/src/fontloader/misc/fontloader-font-oup.lua
index 7edaaf6..3b6d8ea 100644
--- a/src/fontloader/misc/fontloader-font-oup.lua
+++ b/src/fontloader/misc/fontloader-font-oup.lua
@@ -367,18 +367,29 @@ local function copyduplicates(fontdata)
             for u, d in next, duplicates do
                 local du = descriptions[u]
                 if du then
-                    local t  = { f_character_y(u), "@", f_index(du.index), "->" }
+                    local t = { f_character_y(u), "@", f_index(du.index), "->" }
+                    local n = 0
+                    local m = 25
                     for u in next, d do
                         if descriptions[u] then
-                            t[#t+1] = f_character_n(u)
+                            if n < m then
+                                t[n+4] = f_character_n(u)
+                            end
                         else
                             local c = copy(du)
-                         -- c.unicode = u -- maybe
+                            c.unicode = u -- better this way
                             descriptions[u] = c
-                            t[#t+1] = f_character_y(u)
+                            if n < m then
+                                t[n+4] = f_character_y(u)
+                            end
                         end
+                        n = n + 1
+                    end
+                    if n <= m then
+                        report("duplicates: %i : % t",n,t)
+                    else
+                        report("duplicates: %i : % t ...",n,t)
                     end
-                    report("duplicates: % t",t)
                 else
                     -- what a mess
                 end
@@ -577,13 +588,12 @@ local function checklookups(fontdata,missing,nofmissing)
             if r then
                 local name = descriptions[i].name or f_index(i)
                 if not ignore[name] then
-                    done[#done+1] = name
+                    done[name] = true
                 end
             end
         end
-        if #done > 0 then
-            table.sort(done)
-            report("not unicoded: % t",done)
+        if next(done) then
+            report("not unicoded: % t",table.sortedkeys(done))
         end
     end
 end
diff --git a/src/fontloader/misc/fontloader-font-tfm.lua b/src/fontloader/misc/fontloader-font-tfm.lua
index 83ac2f0..8e92c48 100644
--- a/src/fontloader/misc/fontloader-font-tfm.lua
+++ b/src/fontloader/misc/fontloader-font-tfm.lua
@@ -155,7 +155,7 @@ local function read_from_tfm(specification)
         end
         -- let's play safe:
         properties.haskerns     = true
-        properties.haslogatures = true
+        properties.hasligatures = true
         resources.unicodes      = { }
         resources.lookuptags    = { }
         --
diff --git a/src/fontloader/runtime/fontloader-basics-gen.lua b/src/fontloader/runtime/fontloader-basics-gen.lua
index c298f6d..2a68b1c 100644
--- a/src/fontloader/runtime/fontloader-basics-gen.lua
+++ b/src/fontloader/runtime/fontloader-basics-gen.lua
@@ -92,12 +92,10 @@ local remapper = {
     otf    = "opentype fonts",
     ttf    = "truetype fonts",
     ttc    = "truetype fonts",
-    dfont  = "truetype fonts", -- "truetype dictionary",
     cid    = "cid maps",
     cidmap = "cid maps",
-    fea    = "font feature files",
-    pfa    = "type1 fonts", -- this is for Khaled, in ConTeXt we don't use this!
-    pfb    = "type1 fonts", -- this is for Khaled, in ConTeXt we don't use this!
+ -- fea    = "font feature files", -- no longer supported
+    pfb    = "type1 fonts",        -- needed for vector loading
     afm    = "afm",
 }
 
diff --git a/src/fontloader/runtime/fontloader-reference.lua b/src/fontloader/runtime/fontloader-reference.lua
index e784738..5be6493 100644
--- a/src/fontloader/runtime/fontloader-reference.lua
+++ b/src/fontloader/runtime/fontloader-reference.lua
@@ -1,6 +1,6 @@
 -- merged file : c:/data/develop/context/sources/luatex-fonts-merged.lua
 -- parent file : c:/data/develop/context/sources/luatex-fonts.lua
--- merge date  : 04/18/16 22:12:36
+-- merge date  : 04/27/16 10:18:10
 
 do -- begin closure to overcome local limits and interference
 
@@ -3693,11 +3693,8 @@ local remapper={
   otf="opentype fonts",
   ttf="truetype fonts",
   ttc="truetype fonts",
-  dfont="truetype fonts",
   cid="cid maps",
   cidmap="cid maps",
-  fea="font feature files",
-  pfa="type1 fonts",
   pfb="type1 fonts",
   afm="afm",
 }
@@ -5656,9 +5653,13 @@ function constructors.scale(tfmdata,specification)
     elseif autoitalicamount then 
       local vi=description.italic
       if not vi then
-        local vi=description.boundingbox[3]-description.width+autoitalicamount
-        if vi>0 then 
-          chr.italic=vi*hdelta
+        local bb=description.boundingbox
+        if bb then
+          local vi=bb[3]-description.width+autoitalicamount
+          if vi>0 then 
+            chr.italic=vi*hdelta
+          end
+        else
         end
       elseif vi~=0 then
         chr.italic=vi*hdelta
@@ -6408,6 +6409,7 @@ local formatters=string.formatters
 local trace_loading=false trackers.register("fonts.loading",function(v) trace_loading=v end)
 local trace_mapping=false trackers.register("fonts.mapping",function(v) trace_unimapping=v end)
 local report_fonts=logs.reporter("fonts","loading") 
+local force_ligatures=false directives.register("fonts.mapping.forceligatures",function(v) force_ligatures=v end)
 local fonts=fonts or {}
 local mappings=fonts.mappings or {}
 fonts.mappings=mappings
@@ -6676,7 +6678,7 @@ function mappings.addtounicode(data,filename,checklookups)
   local collected=false
   local unicoded=0
   for unicode,glyph in next,descriptions do
-    if not glyph.unicode and glyph.class=="ligature" then
+    if glyph.class=="ligature" and (force_ligatures or not glyph.unicode) then
       if not collected then
         collected=fonts.handlers.otf.readers.getcomponents(data)
         if not collected then
@@ -6927,7 +6929,7 @@ local function read_from_tfm(specification)
       end
     end
     properties.haskerns=true
-    properties.haslogatures=true
+    properties.hasligatures=true
     resources.unicodes={}
     resources.lookuptags={}
     depth[filename]=depth[filename]-1
@@ -6980,9 +6982,11 @@ if not modules then modules={} end modules ['font-afm']={
 }
 local fonts,logs,trackers,containers,resolvers=fonts,logs,trackers,containers,resolvers
 local next,type,tonumber=next,type,tonumber
-local format,match,gmatch,lower,gsub,strip=string.format,string.match,string.gmatch,string.lower,string.gsub,string.strip
+local match,gmatch,lower,gsub,strip,find=string.match,string.gmatch,string.lower,string.gsub,string.strip,string.find
+local char,byte,sub=string.char,string.byte,string.sub
 local abs=math.abs
-local P,S,C,R,lpegmatch,patterns=lpeg.P,lpeg.S,lpeg.C,lpeg.R,lpeg.match,lpeg.patterns
+local bxor,rshift=bit32.bxor,bit32.rshift
+local P,S,R,Cmt,C,Ct,Cs,lpegmatch,patterns=lpeg.P,lpeg.S,lpeg.R,lpeg.Cmt,lpeg.C,lpeg.Ct,lpeg.Cs,lpeg.match,lpeg.patterns
 local derivetable=table.derive
 local trace_features=false trackers.register("afm.features",function(v) trace_features=v end)
 local trace_indexing=false trackers.register("afm.indexing",function(v) trace_indexing=v end)
@@ -6994,15 +6998,11 @@ local findbinfile=resolvers.findbinfile
 local definers=fonts.definers
 local readers=fonts.readers
 local constructors=fonts.constructors
-local fontloader=fontloader
-local font_to_table=fontloader.to_table
-local open_font=fontloader.open
-local close_font=fontloader.close
 local afm=constructors.newhandler("afm")
 local pfb=constructors.newhandler("pfb")
 local afmfeatures=constructors.newfeatures("afm")
 local registerafmfeature=afmfeatures.register
-afm.version=1.500 
+afm.version=1.501 
 afm.cache=containers.define("fonts","afm",afm.version,true)
 afm.autoprefixed=true 
 afm.helpdata={} 
@@ -7111,39 +7111,140 @@ local function get_variables(data,fontmetrics)
     end
   end
 end
-local function get_indexes(data,pfbname)
-  data.resources.filename=resolvers.unresolve(pfbname) 
-  local pfbblob=open_font(pfbname)
-  if pfbblob then
-    local characters=data.characters
-    local pfbdata=font_to_table(pfbblob)
-    if pfbdata then
-      local glyphs=pfbdata.glyphs
-      if glyphs then
-        if trace_loading then
-          report_afm("getting index data from %a",pfbname)
-        end
-        for index,glyph in next,glyphs do
-          local name=glyph.name
-          if name then
-            local char=characters[name]
-            if char then
-              if trace_indexing then
-                report_afm("glyph %a has index %a",name,index)
+local get_indexes
+do
+  local fontloader=fontloader
+  if fontloader then
+    local font_to_table=fontloader.to_table
+    local open_font=fontloader.open
+    local close_font=fontloader.close
+    local function get_indexes_old(data,pfbname)
+      local pfbblob=open_font(pfbname)
+      if pfbblob then
+        local characters=data.characters
+        local pfbdata=font_to_table(pfbblob)
+        if pfbdata then
+          local glyphs=pfbdata.glyphs
+          if glyphs then
+            if trace_loading then
+              report_afm("getting index data from %a",pfbname)
+            end
+            for index,glyph in next,glyphs do
+              local name=glyph.name
+              if name then
+                local char=characters[name]
+                if char then
+                  if trace_indexing then
+                    report_afm("glyph %a has index %a",name,index)
+                  end
+                  char.index=index
+                end
               end
-              char.index=index
             end
+          elseif trace_loading then
+            report_afm("no glyph data in pfb file %a",pfbname)
           end
+        elseif trace_loading then
+          report_afm("no data in pfb file %a",pfbname)
         end
+        close_font(pfbblob)
       elseif trace_loading then
-        report_afm("no glyph data in pfb file %a",pfbname)
+        report_afm("invalid pfb file %a",pfbname)
+      end
+    end
+  end
+  local n,m
+  local progress=function(str,position,name,size)
+    local forward=position+tonumber(size)+3+2
+    n=n+1
+    if n>=m then
+      return #str,name
+    elseif forward<#str then
+      return forward,name
+    else
+      return #str,name
+    end
+  end
+  local initialize=function(str,position,size)
+    n=0
+    m=tonumber(size)
+    return position+1
+  end
+  local charstrings=P("/CharStrings")
+  local name=P("/")*C((R("az")+R("AZ")+R("09")+S("-_."))^1)
+  local size=C(R("09")^1)
+  local spaces=P(" ")^1
+  local p_filternames=Ct (
+    (1-charstrings)^0*charstrings*spaces*Cmt(size,initialize)*(Cmt(name*P(" ")^1*C(R("09")^1),progress)+P(1))^1
+  )
+  local decrypt
+  do
+    local r,c1,c2,n=0,0,0,0
+    local function step(c)
+      local cipher=byte(c)
+      local plain=bxor(cipher,rshift(r,8))
+      r=((cipher+r)*c1+c2)%65536
+      return char(plain)
+    end
+    decrypt=function(binary)
+      r,c1,c2,n=55665,52845,22719,4
+      binary=gsub(binary,".",step)
+      return sub(binary,n+1)
+    end
+  end
+  local function loadpfbvector(filename)
+    local data=io.loaddata(resolvers.findfile(filename))
+    if not find(data,"!PS%-AdobeFont%-") then
+      print("no font",filename)
+      return
+    end
+    if not data then
+      print("no data",filename)
+      return
+    end
+    local ascii,binary=match(data,"(.*)eexec%s+......(.*)")
+    if not binary then
+      print("no binary",filename)
+      return
+    end
+    binary=decrypt(binary,4)
+    local vector=lpegmatch(p_filternames,binary)
+    vector[0]=table.remove(vector,1)
+    if not vector then
+      print("no vector",filename)
+      return
+    end
+    return vector
+  end
+  get_indexes=function(data,pfbname)
+    local vector=loadpfbvector(pfbname)
+    if vector then
+      local characters=data.characters
+      if trace_loading then
+        report_afm("getting index data from %a",pfbname)
+      end
+      for index=1,#vector do
+        local name=vector[index]
+        local char=characters[name]
+        if char then
+          if trace_indexing then
+            report_afm("glyph %a has index %a",name,index)
+          end
+          char.index=index
+        end
+      end
+    end
+  end
+  if fontloader then
+    afm.use_new_indexer=true
+    get_indexes_new=get_indexes
+    get_indexes=function(data,pfbname)
+      if afm.use_new_indexer then
+        return get_indexes_new(data,pfbname)
+      else
+        return get_indexes_old(data,pfbname)
       end
-    elseif trace_loading then
-      report_afm("no data in pfb file %a",pfbname)
     end
-    close_font(pfbblob)
-  elseif trace_loading then
-    report_afm("invalid pfb file %a",pfbname)
   end
 end
 local function readafm(filename)
@@ -7222,6 +7323,7 @@ function afm.load(filename)
       data=readafm(filename)
       if data then
         if pfbname~="" then
+          data.resources.filename=resolvers.unresolve(pfbname)
           get_indexes(data,pfbname)
         elseif trace_loading then
           report_afm("no pfb file for %a",filename)
@@ -7265,7 +7367,8 @@ end
 local uparser=fonts.mappings.makenameparser()
 unify=function(data,filename)
   local unicodevector=fonts.encodings.agl.unicodes 
-  local unicodes,names={},{}
+  local unicodes={}
+  local names={}
   local private=constructors.privateoffset
   local descriptions=data.descriptions
   for name,blob in next,data.characters do
@@ -8142,15 +8245,11 @@ if not modules then modules={} end modules ['font-otr']={
   copyright="PRAGMA ADE / ConTeXt Development Team",
   license="see context related readme files"
 }
-if not characters then
-  require("char-def")
-  require("char-ini")
-end
 local next,type,unpack=next,type,unpack
 local byte,lower,char,strip,gsub=string.byte,string.lower,string.char,string.strip,string.gsub
 local bittest=bit32.btest
-local concat,remove,unpack=table.concat,table.remov,table.unpack
-local floor,mod,abs,sqrt,round=math.floor,math.mod,math.abs,math.sqrt,math.round
+local concat,remove,unpack,fastcopy=table.concat,table.remov,table.unpack,table.fastcopy
+local floor,abs,sqrt,round=math.floor,math.abs,math.sqrt,math.round
 local P,R,S,C,Cs,Cc,Ct,Carg,Cmt=lpeg.P,lpeg.R,lpeg.S,lpeg.C,lpeg.Cs,lpeg.Cc,lpeg.Ct,lpeg.Carg,lpeg.Cmt
 local lpegmatch=lpeg.match
 local setmetatableindex=table.setmetatableindex
@@ -8701,18 +8800,17 @@ readers.hmtx=function(f,fontdata,specification)
       local nofmetrics=fontdata.horizontalheader.nofhmetrics
       local glyphs=fontdata.glyphs
       local nofglyphs=fontdata.nofglyphs
-      local nofrepeated=nofglyphs-nofmetrics
       local width=0 
       local leftsidebearing=0
       for i=0,nofmetrics-1 do
         local glyph=glyphs[i]
         width=readshort(f)
         leftsidebearing=readshort(f)
-        if advance~=0 then
+        if width~=0 then
           glyph.width=width
         end
       end
-      for i=nofmetrics,nofrepeated do
+      for i=nofmetrics,nofglyphs-1 do
         local glyph=glyphs[i]
         if width~=0 then
           glyph.width=width
@@ -8795,6 +8893,7 @@ local sequence={
   { 0,0,6 },
   { 3,0,6 },
   { 0,5,14 },
+  { 3,10,13 },
 }
 local supported={}
 for i=1,#sequence do
@@ -8853,10 +8952,10 @@ formatreaders[4]=function(f,fontdata,offset)
     elseif offset==0xFFFF then
     elseif offset==0 then
       if trace_cmap then
-        report("format 4.%i segment %2i from %C upto %C at index %H",1,segment,startchar,endchar,mod(startchar+delta,65536))
+        report("format 4.%i segment %2i from %C upto %C at index %H",1,segment,startchar,endchar,(startchar+delta)%65536)
       end
       for unicode=startchar,endchar do
-        local index=mod(unicode+delta,65536)
+        local index=(unicode+delta)%65536
         if index and index>0 then
           local glyph=glyphs[index]
           if glyph then
@@ -8885,13 +8984,13 @@ formatreaders[4]=function(f,fontdata,offset)
     else
       local shift=(segment-nofsegments+offset/2)-startchar
       if trace_cmap then
-        report("format 4.%i segment %2i from %C upto %C at index %H",0,segment,startchar,endchar,mod(startchar+delta,65536))
+        report("format 4.%i segment %2i from %C upto %C at index %H",0,segment,startchar,endchar,(startchar+delta)%65536)
       end
       for unicode=startchar,endchar do
         local slot=shift+unicode
         local index=indices[slot]
         if index and index>0 then
-          index=mod(index+delta,65536)
+          index=(index+delta)%65536
           local glyph=glyphs[index]
           if glyph then
             local gu=glyph.unicode
@@ -8966,7 +9065,7 @@ formatreaders[12]=function(f,fontdata,offset)
     local last=readulong(f)
     local index=readulong(f)
     if trace_cmap then
-      report("format 12 from %C to %C",first,last)
+      report("format 12 from %C to %C starts at index %i",first,last,index)
     end
     for unicode=first,last do
       local glyph=glyphs[index]
@@ -8992,6 +9091,49 @@ formatreaders[12]=function(f,fontdata,offset)
   end
   return nofdone
 end
+formatreaders[13]=function(f,fontdata,offset)
+  setposition(f,offset+2+2+4+4) 
+  local mapping=fontdata.mapping
+  local glyphs=fontdata.glyphs
+  local duplicates=fontdata.duplicates
+  local nofgroups=readulong(f)
+  local nofdone=0
+  for i=1,nofgroups do
+    local first=readulong(f)
+    local last=readulong(f)
+    local index=readulong(f)
+    if first<privateoffset then
+      if trace_cmap then
+        report("format 13 from %C to %C get index %i",first,last,index)
+      end
+      local glyph=glyphs[index]
+      local unicode=glyph.unicode
+      if not unicode then
+        unicode=first
+        glyph.unicode=unicode
+        first=first+1
+      end
+      local list=duplicates[unicode]
+      mapping[index]=unicode
+      if not list then
+        list={}
+        duplicates[unicode]=list
+      end
+      if last>=privateoffset then
+        local limit=privateoffset-1
+        report("format 13 from %C to %C pruned to %C",first,last,limit)
+        last=limit
+      end
+      for unicode=first,last do
+        list[unicode]=true
+      end
+      nofdone=nofdone+last-first+1
+    else
+      report("format 13 from %C to %C ignored",first,last)
+    end
+  end
+  return nofdone
+end
 formatreaders[14]=function(f,fontdata,offset)
   if offset and offset~=0 then
     setposition(f,offset)
@@ -13831,16 +13973,28 @@ local function copyduplicates(fontdata)
         local du=descriptions[u]
         if du then
           local t={ f_character_y(u),"@",f_index(du.index),"->" }
+          local n=0
+          local m=25
           for u in next,d do
             if descriptions[u] then
-              t[#t+1]=f_character_n(u)
+              if n<m then
+                t[n+4]=f_character_n(u)
+              end
             else
               local c=copy(du)
+              c.unicode=u 
               descriptions[u]=c
-              t[#t+1]=f_character_y(u)
+              if n<m then
+                t[n+4]=f_character_y(u)
+              end
             end
+            n=n+1
+          end
+          if n<=m then
+            report("duplicates: %i : % t",n,t)
+          else
+            report("duplicates: %i : % t ...",n,t)
           end
-          report("duplicates: % t",t)
         else
         end
       end
@@ -14025,13 +14179,12 @@ local function checklookups(fontdata,missing,nofmissing)
       if r then
         local name=descriptions[i].name or f_index(i)
         if not ignore[name] then
-          done[#done+1]=name
+          done[name]=true
         end
       end
     end
-    if #done>0 then
-      table.sort(done)
-      report("not unicoded: % t",done)
+    if next(done) then
+      report("not unicoded: % t",table.sortedkeys(done))
     end
   end
 end
@@ -15486,7 +15639,7 @@ local trace_defining=false registertracker("fonts.defining",function(v) trace_de
 local report_otf=logs.reporter("fonts","otf loading")
 local fonts=fonts
 local otf=fonts.handlers.otf
-otf.version=3.017 
+otf.version=3.018 
 otf.cache=containers.define("fonts","otl",otf.version,true)
 local otfreaders=otf.readers
 local hashes=fonts.hashes
@@ -16527,8 +16680,6 @@ local attributes,nodes,node=attributes,nodes,node
 fonts=fonts
 local hashes=fonts.hashes
 local fontdata=hashes.identifiers
-local parameters=fonts.hashes.parameters
-local resources=fonts.hashes.resources
 nodes.injections=nodes.injections or {}
 local injections=nodes.injections
 local tracers=nodes.tracers
@@ -17718,7 +17869,7 @@ local function injectspaces(head)
   local function updatefont(font,trig)
     leftkerns=trig.left
     rightkerns=trig.right
-    local par=parameters[font]
+    local par=fontdata[font].parameters 
     factor=par.factor
     threshold=par.spacing.width-1 
     lastfont=font
@@ -18566,7 +18717,21 @@ local function toligature(head,start,stop,char,dataset,sequence,markflag,discfou
       local pre,post,replace,pretail,posttail,replacetail=getdisc(discfound,true)
       if not replace then 
         local prev=getprev(base)
-        local copied=copy_node_list(comp)
+local current=comp
+local previous=nil
+local copied=nil
+while current do
+  if getid(current)==glyph_code then
+    local n=copy_node(current)
+    if copied then
+      setlink(previous,n)
+    else
+      copied=n
+    end
+    previous=n
+  end
+  current=getnext(current)
+end
         setprev(discnext,nil) 
         setnext(discprev,nil) 
         if pre then
@@ -19871,7 +20036,7 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
         else
           local discfound=nil
           local n=f+1
-          last=getnext(last)
+          last=getnext(last) 
           while n<=l do
             if not last and (sweeptype=="post" or sweeptype=="replace") then
               last=getnext(sweepnode)
@@ -19912,7 +20077,6 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                   end
                   break
                 end
-                last=getnext(last)
               elseif char==false then
                 if discfound then
                   notmatchreplace[discfound]=true
@@ -19997,8 +20161,12 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                       if trace_skips then
                         show_skip(dataset,sequence,char,ck,class)
                       end
+                      prev=getprev(prev) 
                     elseif seq[n][char] then
-                      n=n -1
+                      if n>1 then 
+                        prev=getprev(prev) 
+                      end
+                      n=n-1
                     else
                       if discfound then
                         notmatchreplace[discfound]=true
@@ -20017,7 +20185,6 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                     end
                     break
                   end
-                  prev=getprev(prev)
                 elseif char==false then
                   if discfound then
                     notmatchreplace[discfound]=true
@@ -20079,19 +20246,19 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                       if not match then
                         break
                       end
-                    else
                     end
-                  else
                   end
+                  prev=getprev(prev)
                 elseif seq[n][32] then
                   n=n-1
+                  prev=getprev(prev)
                 else
                   match=false
                   break
                 end
-                prev=getprev(prev)
               elseif seq[n][32] then 
                 n=n-1
+                prev=getprev(prev) 
               else
                 match=false
                 break
@@ -20126,7 +20293,11 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                     if trace_skips then
                       show_skip(dataset,sequence,char,ck,class)
                     end
+                    current=getnext(current) 
                   elseif seq[n][char] then
+                    if n<s then 
+                      current=getnext(current) 
+                    end
                     n=n+1
                   else
                     if discfound then
@@ -20200,16 +20371,16 @@ local function handle_contextchain(head,start,dataset,sequence,contexts,rlmode)
                   end
                 else
                 end
+                current=getnext(current)
               elseif seq[n][32] then 
                 n=n+1
               else
                 match=false
                 break
               end
-              current=getnext(current)
             elseif seq[n][32] then
               n=n+1
-current=getnext(current)
+              current=getnext(current)
             else
               match=false
               break