2018-02-21 18:27:00

20 files changed, 635 insertions, 576 deletions

diff --git a/tex/context/base/mkiv/buff-imp-tex.lua b/tex/context/base/mkiv/buff-imp-tex.lua
index 13ecdf27f..606c31d36 100644
--- a/tex/context/base/mkiv/buff-imp-tex.lua
+++ b/tex/context/base/mkiv/buff-imp-tex.lua
@@ -43,7 +43,7 @@ local handler = visualizers.newhandler {
 -- todo: unicode letters in control sequences (slow as we need to test the nature)
 
 local comment  = S("%")
-local name     = P("\\") * (patterns.letter + S("@!?_"))^1
+local name     = P("\\") * (patterns.letter + S("@!?_") + patterns.utf8two + patterns.utf8three + patterns.utf8four)^1
 local escape   = P("\\") * (patterns.anything - patterns.newline)^-1 -- else we get \n
 local group    = S("${}")
 local boundary = S('[]()<>#="')
diff --git a/tex/context/base/mkiv/cont-fil.mkiv b/tex/context/base/mkiv/cont-fil.mkiv
index 69c45c0e5..507effd02 100644
--- a/tex/context/base/mkiv/cont-fil.mkiv
+++ b/tex/context/base/mkiv/cont-fil.mkiv
@@ -114,22 +114,28 @@
 \definefilesynonym [memo]            [cor-02]
 \definefilesynonym [resume]          [cor-03]
 
-% downward compatible mapping:
-
-\definefilesynonym [pre-41]          [present-tiles]
-\definefilesynonym [fnt-29]          [fonts-shapes]
-\definefilesynonym [fnt-33]          [math-coverage]
-\definefilesynonym [mat-12]          [math-parameters]
-\definefilesynonym [mat-20]          [math-parameters]
+\definefilesynonym [fnt-10]          [fonts-complete]
+\definefilesynonym [fnt-11]          [fonts-system]
+\definefilesynonym [fnt-20]          [fonts-steps]
+\definefilesynonym [fnt-21]          [fonts-steps]
+\definefilesynonym [fnt-22]          [fonts-engines]
+\definefilesynonym [fnt-23]          [fonts-shapes]
+\definefilesynonym [fnt-24]          [fonts-cjk]
 \definefilesynonym [fnt-25]          [math-characters]
 \definefilesynonym [fnt-28]          [fonts-goodies]
+\definefilesynonym [fnt-29]          [fonts-shapes]
 \definefilesynonym [fnt-31]          [fonts-coverage]
+\definefilesynonym [fnt-33]          [math-coverage]
+
 \definefilesynonym [mat-10]          [math-characters]
 \definefilesynonym [mat-11]          [math-characters]
-\definefilesynonym [fnt-11]          [fonts-system]
-\definefilesynonym [fnt-23]          [fonts-shapes]
+\definefilesynonym [mat-12]          [math-parameters]
+\definefilesynonym [mat-20]          [math-parameters]
+
 \definefilesynonym [syn-01]          [syntax]
 
+\definefilesynonym [reg-01]          [regimes-list]
+
 \definefilesynonym [set-11]          [setups-basics]
 \definefilesynonym [set-12]          [setups-overview]
 %definefilesynonym [set-13]          [setups-proofing]
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index 03714b5c7..b48f7a39e 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2018.02.19 18:56}
+\newcontextversion{2018.02.21 18:19}
 
 %D This file is loaded at runtime, thereby providing an excellent place for
 %D hacks, patches, extensions and new features.
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index 6c5b378b0..53ef6e71c 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -41,7 +41,7 @@
 %D up and the dependencies are more consistent.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2018.02.19 18:56}
+\edef\contextversion{2018.02.21 18:19}
 \edef\contextkind   {beta}
 
 %D For those who want to use this:
diff --git a/tex/context/base/mkiv/core-def.mkiv b/tex/context/base/mkiv/core-def.mkiv
index acd411fac..0e7cd2d2e 100644
--- a/tex/context/base/mkiv/core-def.mkiv
+++ b/tex/context/base/mkiv/core-def.mkiv
@@ -53,9 +53,9 @@
     \flushnotes
 \to \everydisplay
 
-\appendtoks
-    \adjustsidefloatdisplaylines
-\to \everydisplay
+% \appendtoks
+%     \adjustsidefloatdisplaylines
+% \to \everydisplay
 
 % \appendtoks
 %     \flushpostponednodedata
diff --git a/tex/context/base/mkiv/font-tra.mkiv b/tex/context/base/mkiv/font-tra.mkiv
index 566897240..c51ba78fc 100644
--- a/tex/context/base/mkiv/font-tra.mkiv
+++ b/tex/context/base/mkiv/font-tra.mkiv
@@ -309,7 +309,7 @@
 \letvalue{\??otfcompositiondir   1}\lefttoright
 
 \unexpanded\def\setotfcompositiondirection#1%
- {\getvalue{\??otfcompositiondir#1}}
+ {\begincsname\??otfcompositiondir#1\endcsname}
 
 \unexpanded\def\showotfcomposition#1#2#3% {font*features at size}, rl=-1, text
   {\begingroup
diff --git a/tex/context/base/mkiv/mtx-context-arrange.tex b/tex/context/base/mkiv/mtx-context-arrange.tex
index a3e6e9db3..e970ac450 100644
--- a/tex/context/base/mkiv/mtx-context-arrange.tex
+++ b/tex/context/base/mkiv/mtx-context-arrange.tex
@@ -27,8 +27,8 @@
 % --printformat           : 2UP, etc
 % --paperformat=spec      : paper*print or paperxprint
 %
-% example: context --extra=arrange --printformat=2UP --paperformat=A4*A3,landscape myfile
-%
+% example: context --extra=arrange --printformat=2UP --paperformat=A4*A3,landscape               myfile
+%          context --extra=arrange --printformat=xy  --paperformat=A4*A2           --nx=2 --ny=2 myfile
 % end help
 
 \input mtx-context-common.tex
@@ -79,6 +79,20 @@
     local printformat = document.arguments.printformat or ""
     if printformat == "" then
         printformat = "normal"
+    elseif string.find(printformat,"xy") then
+        if false then
+            context.setuplayout {
+                nx = document.arguments.nx or 1,
+                ny = document.arguments.ny or 1,
+            }
+            printformat = "XY,\\v!rotated"
+        else
+            context.setuppaper {
+                nx = document.arguments.nx or 1,
+                ny = document.arguments.ny or 1,
+            }
+            printformat = "XY"
+        end
     elseif string.find(printformat,".*up") then
         printformat = "2UP,\\v!rotated"
     elseif string.find(printformat,".*down") then
@@ -107,7 +121,7 @@
         local textwidth  = arguments.textwidth or "0cm"
         for i=1,noffiles do
             local filename = files[i]
-            if not string.find(filename,"^mtx%-context%-") then
+            if not string.find(file.basename(filename),"^mtx%-context%-") then
                 context.insertpages (
                     { filename },
                     { emptypages },
diff --git a/tex/context/base/mkiv/mult-low.lua b/tex/context/base/mkiv/mult-low.lua
index 1fea62f6a..50ddeff2c 100644
--- a/tex/context/base/mkiv/mult-low.lua
+++ b/tex/context/base/mkiv/mult-low.lua
@@ -278,7 +278,7 @@ return {
         "singleexpandafter", "doubleexpandafter", "tripleexpandafter",
         --
         "dontleavehmode", "removelastspace", "removeunwantedspaces", "keepunwantedspaces",
-        "removepunctuation",
+        "removepunctuation", "ignoreparskip",
         --
         "wait", "writestatus", "define", "defineexpandable", "redefine",
         --
diff --git a/tex/context/base/mkiv/mult-mes.lua b/tex/context/base/mkiv/mult-mes.lua
index 21bb16eab..1eb429763 100644
--- a/tex/context/base/mkiv/mult-mes.lua
+++ b/tex/context/base/mkiv/mult-mes.lua
@@ -498,6 +498,9 @@ return {
             en = "location %a changed to %a due to exporting",
             nl = "plaatsing %a vervangen door %a vanwege export",
         },
+        ["floatblocks:16"] = {
+            en = "anchor=orange, shift=red, box=green, dummy=blue, line=cyan, depth=magenta, prev=orange",
+        },
         ["floatblocks:1"] = {
             en = "%a is empty",
         },
diff --git a/tex/context/base/mkiv/page-sid.mkiv b/tex/context/base/mkiv/page-sid.mkiv
index 31c962719..a777efa32 100644
--- a/tex/context/base/mkiv/page-sid.mkiv
+++ b/tex/context/base/mkiv/page-sid.mkiv
@@ -18,16 +18,18 @@
 %D These macro deal with side floats. We started with Daniel Comenetz macros as
 %D published in TUGBoat Volume 14 (1993), No.\ 1: Anchored Figures at Either Margin.
 %D I extended and patched the macros to suite our needs which results in a messy
-%D module. Therefore, this module badly needs an update because it's now a mixture
-%D of old and new macros.
-
-% Interesting cases where it goes wrong:
-%
-% \placefigure[left]{}{} \dorecurse{3}{\input ward } {\par} \input ward
-
+%D module.
+%D
 %D A complication is that we need to deal with spacing differently before and after
-%D the float. Also, whitespace can interfere as does the prevdepth. There is no
-%D real universal solotion.
+%D the float. Also, whitespace can interfere as does the prevdepth. There is no real
+%D universal solution. So, by now not much is left of that code, if only because we
+%D need to match \CONTEXT\ spacing module, because we have more placement options
+%D and control and because the math hackery is not suitable for \CONTEXT\ anyway.
+%D
+%D This code had been redone many times because we kept running into spacing issues
+%D and it's not that much fun (or rewarding). It's probably the module that made
+%D me go into distraciton mode most often (like watching amusing Walk of The
+%D Earth or sophisticated Massive Attack video clips).
 
 \newdimen       \d_page_sides_height       % includes the topskip
 \newdimen       \d_page_sides_width
@@ -36,9 +38,8 @@
 \newdimen       \d_page_sides_vsize_reset
 \newdimen       \d_page_sides_progress
 \newdimen       \d_page_sides_page_total
-\newdimen       \d_page_sides_saved_depth
 
-\newbox         \b_page_sides_bottom
+%newbox         \b_page_sides_bottom
 
 \newcount       \c_page_sides_lines_done
 \newcount       \c_page_sides_checks_done
@@ -48,7 +49,6 @@
 
 \newconditional \c_page_sides_short
 \newconditional \c_page_sides_flag
-\newconditional \c_page_sides_dummy_lines
 
 \newdimen       \d_page_sides_shift
 \newdimen       \d_page_sides_extrashift
@@ -67,15 +67,35 @@
 \newdimen       \d_page_sides_toptotal
 \newdimen       \d_page_sides_bottomtotal
 
-\setnewconstant \c_page_sides_method   \plusone
-\setnewconstant \c_page_sides_align    \zerocount
-\setnewconstant \c_page_sides_skipmode \zerocount
-\setnewconstant \c_page_sides_tolerance\zerocount
+\newconstant    \c_page_sides_align
+\newconstant    \c_page_sides_skipmode
+\newconstant    \c_page_sides_tolerance
+
+\newconstant    \c_page_sides_method % sort of obsolete
+
+\newdimen       \d_page_sides_progression
+
+\newif          \iftracesidefloats % public (might change)
+
+%D Defaults:
 
 \d_page_sides_vsize_reset -\onepoint
 %d_page_sides_vsize_reset  \zeropoint % could be an option, needs testing
 
-\settrue\c_page_sides_dummy_lines     % when false gets reset to true afterwards
+%D We have some basic (and colorful) tracing:
+
+\def\page_sides_floats_legend
+  {\showmessage\m!floatblocks{16}\empty
+   \glet\page_sides_floats_legend\relax}
+
+\installtextracker{floats.anchoring}
+  {\page_sides_floats_legend
+   \tracesidefloatstrue}
+  {\tracesidefloatsfalse}
+
+%D The horizontal shifts depend on the location: left or right in the text, margin
+%D or edge. These shifts are rather stable and don't interfere with the page flow
+%D as much as the vertical ones do.
 
 \def\page_sides_process_float_backspace  {\global\c_page_sides_float_type\plusone  \page_sides_handle_float}
 \def\page_sides_process_float_leftedge   {\global\c_page_sides_float_type\plustwo  \page_sides_handle_float}
@@ -87,41 +107,14 @@
 \def\page_sides_process_float_cutspace   {\global\c_page_sides_float_type\pluseight\page_sides_handle_float}
 \def\page_sides_process_float_margin     {\global\c_page_sides_float_type\pluseight\page_sides_handle_float}
 
-\def\page_sides_check_skips
-  {\global\d_page_sides_toptotal   \dimexpr\d_page_sides_topskip   +\d_page_sides_topoffset   \relax
-   \global\d_page_sides_bottomtotal\dimexpr\d_page_sides_bottomskip+\d_page_sides_bottomoffset\relax
-   \ifcase\c_page_sides_skipmode
+\def\page_sides_check_horizontal_skips
+  {\ifcase\c_page_sides_skipmode
    \or % high
-     \global\d_page_sides_toptotal   \d_page_sides_topoffset
    \or % low
-     \global\d_page_sides_bottomtotal\d_page_sides_bottomoffset
    \or % fit
-     \global\d_page_sides_toptotal   \d_page_sides_topoffset
-     \global\d_page_sides_bottomtotal\d_page_sides_bottomoffset
-     \global\d_strc_floats_margin    \zeropoint
+     \global\d_strc_floats_margin\zeropoint
    \fi}
 
-\newif\iftracesidefloats % public (might change)
-
-\unexpanded\def\page_sides_force_depth
-  {\iftracesidefloats
-     \begingroup
-     \c_page_force_strut_depth_trace_mode\plusone
-     \forcestrutdepth
-     \endgroup
-   \else
-     \forcestrutdepth
-   \fi}
-
-\def\page_sides_floats_legend
-  {\writestatus\m!floatblocks{anchor: orange, shift: red, box: green, dummy: blue, depth: magenta}%
-   \glet\page_sides_floats_legend\relax}
-
-\installtextracker{floats.anchoring}
-  {\page_sides_floats_legend
-   \tracesidefloatstrue}
-  {\tracesidefloatsfalse}
-
 \def\page_sides_apply_horizontal_shift
   {\ifdim\d_page_sides_maximum>\zeropoint
      \ifcase\c_page_sides_float_type
@@ -221,12 +214,189 @@
        +\compensatedinnermakeupmargin
      \relax
    \fi
-   \ifdim\d_page_sides_rightskip>\zeropoint \global\advance\d_page_sides_rightskip\rightskip \fi
-   \ifdim\d_page_sides_leftskip >\zeropoint \global\advance\d_page_sides_leftskip \leftskip  \fi}
+   \ifdim\d_page_sides_rightskip>\zeropoint
+     \global\advance\d_page_sides_rightskip\rightskip
+   \fi
+   \ifdim\d_page_sides_leftskip >\zeropoint
+     \global\advance\d_page_sides_leftskip \leftskip
+   \fi}
+
+%D Shifts get applied to the float box:
+
+\def\page_sides_relocate_float#1%
+  {\global\setbox\floatbox\hpack
+     {\ifnum\c_page_sides_float_type=\plusfour
+        \kern\d_page_sides_leftshift
+      \else\ifnum\c_page_sides_float_type=\plusone
+        \kern\d_page_sides_leftshift
+      \fi\fi
+      \ifnum\c_page_sides_float_type>\plusfour
+        \kern-\d_page_sides_extrashift
+      \else
+        \kern\d_page_sides_shift
+      \fi
+      \vbox{#1\ifnum\c_page_sides_align=\plusfour \removedepth \fi}%
+      \ifnum\c_page_sides_float_type>\plusfour
+        \kern\d_page_sides_shift
+      \else
+        \kern-\d_page_sides_extrashift
+      \fi
+      \ifnum\c_page_sides_float_type=\pluseight
+        \kern\d_page_sides_rightshift
+      \else\ifnum\c_page_sides_float_type=\plusfive
+        \kern\d_page_sides_rightshift
+      \fi\fi}}
+
+%D The vertical skips are a nightmare and this mechanism is about as complex
+%D as one can get it.
+
+\def\page_sides_check_vertical_skips
+  {\ifdim\d_page_sides_topskip   <\zeropoint\d_page_sides_topskip   \zeropoint\fi
+   \ifdim\d_page_sides_bottomskip<\zeropoint\d_page_sides_bottomskip\zeropoint\fi
+   \ifdim\d_page_sides_midskip   <\zeropoint\d_page_sides_midskip   \zeropoint\fi
+   %
+   \global\d_page_sides_toptotal   \dimexpr\d_page_sides_topskip   +\d_page_sides_topoffset   \relax
+   \global\d_page_sides_bottomtotal\dimexpr\d_page_sides_bottomskip+\d_page_sides_bottomoffset\relax
+   \ifcase\c_page_sides_skipmode
+   \or % high
+     \global\d_page_sides_toptotal   \d_page_sides_topoffset
+   \or % low
+     \global\d_page_sides_bottomtotal\d_page_sides_bottomoffset
+   \or % fit
+     \global\d_page_sides_toptotal   \d_page_sides_topoffset
+     \global\d_page_sides_bottomtotal\d_page_sides_bottomoffset
+   \fi}
+
+%D These shifts get (selectively) applied with a bit of optional tracing.
+
+\def\page_sides_apply_vertical_shift_normal
+  {\global\setbox\floatbox\hpack % why extra box
+     {\vpack
+        {\forgetall
+         \hsize\wd\floatbox
+         \vskip\privatescratchdimen
+         \offinterlineskip
+         \box\floatbox
+         % somehow we need this \scratchbox magic, but at least it's the same as the
+         % tracer now
+         \setbox\scratchbox\emptybox
+         \wd\scratchbox\hsize
+         \ht\scratchbox\d_page_sides_bottomtotal
+         \box\scratchbox
+         \vskip-\d_page_sides_bottomtotal
+         \ifnum\c_page_sides_align=\plusfive
+           \vskip-\lineheight
+         \fi}}}
+
+\def\page_sides_apply_vertical_shift_traced
+  {\global\setbox\floatbox\hpack % why extra box
+     {\backgroundline[trace:r]{\ruledhpack{\vpack
+        {\forgetall
+         \hsize\wd\floatbox
+         \vskip\privatescratchdimen
+         \offinterlineskip
+         \backgroundline
+           [trace:g]%
+           {\ruledhpack{\box\floatbox}}%
+         \par
+         \blackrule
+           [\c!color=trace:s,%
+            \c!height=\d_page_sides_bottomtotal,%
+            \c!depth=\zeropoint,%
+            \c!width=\hsize]%
+         \vskip-\d_page_sides_bottomtotal
+         \ifnum\c_page_sides_align=\plusfive
+           \vskip-\lineheight
+         \fi}}}}}
+
+\def\page_sides_apply_vertical_shift
+  {\ifnum\c_page_sides_align=\plusfour
+     \getnoflines{\ht\floatbox}%
+     \privatescratchdimen\dimexpr\noflines\lineheight-\strutdp\relax
+     \getrawnoflines\d_page_sides_toptotal
+     \advance\privatescratchdimen\noflines\lineheight
+     \page_sides_force_depth
+     \ht\floatbox\privatescratchdimen
+     \dp\floatbox\zeropoint
+   \fi
+   \ifcase\c_page_sides_align \else
+     \global\d_page_sides_toptotal\zeropoint
+   \fi
+   \privatescratchdimen
+     \ifnum\c_page_sides_float_type<\plusfour
+       \d_page_sides_toptotal
+     \else\ifnum\c_page_sides_float_type>\plusfive
+       \d_page_sides_toptotal
+     \else
+       \zeropoint
+     \fi\fi
+   % the top of the box is at the previous baseline
+   \ifcase\c_page_sides_align
+       % 0 normal
+     \advance\privatescratchdimen\strutdp % or \openstrutdepth
+   \or % 1 height
+     \advance\privatescratchdimen\strutdp % or \openstrutdepth
+   \or % 2 line
+   \or % 3 depth
+     \advance\privatescratchdimen\lineheight % or \openlineheight
+     \advance\privatescratchdimen\strutdp    % or \openstrutdepth
+   \or % 4 grid
+     \privatescratchdimen\zeropoint
+   \or
+     \advance\privatescratchdimen\strutht % or \openstrutheight
+   \fi
+   % new
+   \global\c_page_sides_lines_done\zerocount
+   \ifnum\c_page_sides_n_of_lines>\zerocount
+     \advance\privatescratchdimen\c_page_sides_n_of_lines\lineheight
+   \fi
+   \iftracesidefloats
+     \page_sides_apply_vertical_shift_traced % uses \privatescratchdimen
+   \else
+     \page_sides_apply_vertical_shift_normal % uses \privatescratchdimen
+   \fi
+   \ifnum\c_page_sides_float_type<\plusfour
+     \global\d_page_sides_toptotal\zeropoint
+   \else\ifnum\c_page_sides_float_type>\plusfive
+     \global\d_page_sides_toptotal\zeropoint
+   \fi\fi
+   \global\d_page_sides_downshift\zeropoint}
+
+%D We have a few virtual dimensions. I'm not sure what to do with \type
+%D {\pagedepth} and \type {\pageshrink} in the next two. If we ever need
+%D that it will become options.
+
+\def\e_page_sides_flush_criterium
+  {\dimexpr
+      \d_page_sides_vsize
+     -\d_page_sides_bottomtotal
+     -\pagetotal
+   \relax}
+
+\def\e_page_sides_room_criterium
+  {\dimexpr
+      \d_page_sides_vsize
+     -\d_page_sides_bottomtotal % added here too
+     -\pagetotal
+   \relax}
+
+%D In order to get a consistent spacing we force a strutdepth unless the
+%D preceding material has more depth than that already. This way anchoring
+%D becomes predictable.
+
+\unexpanded\def\page_sides_force_depth
+  {\iftracesidefloats
+     \begingroup
+     \c_page_force_strut_depth_trace_mode\plusone
+     \forcestrutdepth
+     \endgroup
+   \else
+     \forcestrutdepth
+   \fi}
 
 \def\page_sides_flush_floats
   {\par
-   \ifdim\dimexpr\d_page_sides_vsize-\d_page_sides_bottomtotal-\pagetotal\relax>\zeropoint % -\pagedepth
+   \ifdim\e_page_sides_flush_criterium>\zeropoint
      \page_sides_flush_floats_progress
      \page_sides_flush_floats_after_next
    \fi
@@ -234,14 +404,8 @@
 
 \def\page_sides_flush_floats_text
   {\par
-   \ifdim\dimexpr
-     \d_page_sides_vsize
-% no longer with the adapted skipper
-%     \ifnum\c_anch_backgrounds_text_level>\plusone
-       -\d_page_sides_bottomtotal
-%     \fi
-       -\pagetotal
-        \relax>\zeropoint % -\pagedepth
+   % what with \c_anch_backgrounds_text_level>\plusone
+   \ifdim\e_page_sides_flush_criterium>\zeropoint
      \page_sides_flush_floats_progress
      \page_sides_flush_floats_after_none
    \fi
@@ -254,9 +418,25 @@
    \global\setfalse\c_page_sides_flag
    \global\c_page_sides_checks_done\zerocount}
 
+\def\page_sides_flush_floats_after_none % we force a flush
+  {\ifdim\d_page_sides_midskip>\zeropoint
+      \blank[\the\d_page_sides_midskip]
+   \fi
+   \ignoreparskip
+   \blank[\v!disable]}
+
+\def\page_sides_flush_floats_after_next % we have two successive ones
+  {\ifdim\d_page_sides_bottomskip>\zeropoint
+      \blank[\the\d_page_sides_bottomskip]
+   \fi
+   \ignoreparskip
+   \blank[\v!disable]}
+
+%D A rudimentary checker:
+
 \unexpanded\def\doifelsesidefloat
   {\par
-   \ifdim\dimexpr\d_page_sides_vsize-\pagetotal\relax>\zeropoint % -\pagedepth
+   \ifdim\e_page_sides_room_criterium>\zeropoint % -\pagedepth
      \expandafter\firstoftwoarguments
    \else
      \expandafter\secondoftwoarguments
@@ -264,6 +444,10 @@
 
 \let\doifsidefloatelse\doifelsesidefloat
 
+%D Sometimes we need to fill up the space alongside a side float and this
+%D is where we define the helpers. A user can enforce a smaller step. We use
+%D large steps when possible.
+
 \installcorenamespace{sidefloatsteps}
 
 \setvalue{\??sidefloatsteps\v!line  }{\strut}
@@ -271,8 +455,6 @@
 \setvalue{\??sidefloatsteps\v!medium}{\halflinestrut} % was \halfstrut
 \setvalue{\??sidefloatsteps\v!small }{\noheightstrut} % was \quarterstrut
 
-% we don't officially know what kind of float we flush
-
 \def\page_sides_flush_floats_tracer
   {\dontleavehmode
    \ruledhpack\bgroup\backgroundline[trace:b]{%
@@ -296,6 +478,7 @@
 \def\page_sides_flush_floats_progress
   {\begingroup
    \page_sides_force_depth
+   \parskip\zeropoint
    \let\page_sides_flush_floats\relax
    \edef\m_pages_strut
      {\ifcsname\??sidefloatsteps\rootfloatparameter\c!step\endcsname
@@ -306,13 +489,8 @@
    \forgetall
    \offinterlineskip
    \doloop
-     {\scratchdimen\dimexpr
-         \d_page_sides_vsize
-        -\d_page_sides_bottomtotal
-        -\pagetotal
-      % -\pagedepth
-      \relax
-      \ifdim\scratchdimen>\onepoint % good enough, if we change it it will become a threshold
+     {\scratchdimen\e_page_sides_flush_criterium
+      \ifdim\scratchdimen>\onepoint      % good enough, can become configurable
         \ifnum\recurselevel>\plushundred % safeguard, sort of deadcycles
           \exitloop
         \else\iftracesidefloats
@@ -324,17 +502,55 @@
         \page_sides_force_depth
         \exitloop
       \fi}%
-   \global\setfalse\c_page_sides_dummy_lines
    \endgroup}
 
+%D We force a parskip and ignore it afterwards. We can nil it by setting the
+%D \type {spacebeforeside} parameter. We can have a leading blank so we need
+%D to make sure that we use blank to inject the parskip and then ignore
+%D the one injected by the engine.
 
-\def\page_sides_flush_floats_after_none % we force a flush
-  {\checkedblank[\rootfloatparameter\c!sidespaceafter]%
-   \page_sides_inject_after}
+\def\page_sides_inject_before
+  {\page_sides_force_depth
+   \ifdim\parskip>\zeropoint
+     \ifdim\parskip>\d_strc_floats_top
+       \ifdim\d_strc_floats_top>\zeropoint
+         \ignoreparskip
+         \blank[\v!white]%
+       \else
+         \checkedblank[\rootfloatparameter\c!spacebeforeside]%
+       \fi
+     \else
+       \checkedblank[\rootfloatparameter\c!spacebeforeside]%
+     \fi
+   \else
+     \checkedblank[\rootfloatparameter\c!spacebeforeside]%
+   \fi}
 
-\def\page_sides_flush_floats_after_next % we have two successive ones
-  {\checkedblank[\rootfloatparameter\c!sidespaceinbetween]% maybe also none
-   \page_sides_inject_after}
+%D We are now done with \type {spacebefore} and the parskip is already
+%D injected. The dummy line makes sure that we anchor properly and it
+%D also can serve as tracer.
+
+\def\page_sides_inject_dummy_line_normal
+  {\hpack to \availablehsize{\strut\hss}}
+
+\def\page_sides_inject_dummy_line_traced
+  {\ruledhpack to \availablehsize{\backgroundline[trace:c]{\page_sides_inject_dummy_line_normal}}}
+
+\def\page_sides_inject_dummy_lines
+  {\par
+   \nointerlineskip
+   \dontleavehmode
+   \iftracesidefloats
+     \page_sides_inject_dummy_line_traced
+   \else
+     \page_sides_inject_dummy_line_normal
+   \fi
+   \vskip-\dimexpr\lineheight+\strutdp\relax
+   \ignoreparskip
+   \blank[\v!samepage]
+   \blank[\v!disable]}
+
+%D Checkers:
 
 \def\page_sides_check_floats_after_par
   {\page_sides_check_floats_indeed
@@ -355,184 +571,23 @@
    \global\setfalse\c_page_sides_short
    \global\setfalse\c_page_sides_flag}
 
-\let\page_otr_sides_pop_penalties \relax
-\let\page_otr_sides_push_penalties\relax
-
-\def\page_sides_restore_output_penalty
-  {\ifnum\outputpenalty=\plustenthousand \else
-     \penalty\outputpenalty
-   \fi}
+%D Here comes the output routine. We either go the fast route or we use the
+%D normal one (stored in \type {\page_otr_command_side_float_output}. We no
+%D longer have this fuzzy code around with penalties and indentation and
+%D such.
 
 \def\page_sides_output_routine
-  {\ifconditional\c_page_sides_short
-     % Is this branch ever entered?
-     \page_sides_output_routine_yes
-   \else
-     \page_sides_output_routine_nop
-   \fi}
-
-\def\page_sides_output_routine_nop
-  {\page_otr_command_side_float_output % otr specific
-   \global\d_page_sides_vsize\d_page_sides_vsize_reset
-   \global\c_page_sides_n_of_lines\zerocount
-   % we can end up in fig lock, so \global\holdinginserts\zerocount here too ?
-   \page_otr_sides_pop_penalties}
-
-\def\page_sides_output_routine_yes % we need to rework this ... add pagediscards and such
-  {\unvbox\normalpagebox % bah, and the discards?
-   \setbox\b_page_sides_bottom\lastbox
-   \ifvoid\b_page_sides_bottom
-     % go on
-   \else\ifdim\wd\b_page_sides_bottom>\d_page_sides_hsize
-     % hm, i really need to write this from scratch
-     \penalty-201
-     \box\b_page_sides_bottom
+  {\page_otr_command_side_float_output
+   \ifconditional\c_page_sides_short
+     \global\setfalse\c_page_sides_short
    \else
-     \page_sides_restore_left_indent
-     \ifdim\wd\b_page_sides_bottom<\d_page_sides_hsize
-       \parskip\zeropoint
-       %\noindent
-       \ifinner\else
-         \vadjust{\penalty\minusone}%
-       \fi
-       \global\advance\d_page_sides_hsize -\wd\b_page_sides_bottom
-       \global\divide\d_page_sides_hsize \plustwo
-       \hskip\d_page_sides_hsize % \kern
-     \fi
-     \box\b_page_sides_bottom
-     \page_sides_restore_output_penalty
-   \fi\fi
-   % why was this \global\holdinginserts\zerocount
-   \global\setfalse\c_page_sides_short}
-
-\def\page_sides_restore_left_indent
-  {\relax
-   \ifnum\c_page_sides_float_type>\plusfour \else
-     \parskip\zeropoint % here ?
-     \ifdim\d_page_sides_width>\zeropoint % new, see prikkels
-       \noindent
-       \ifinner \else
-         \vadjust{\penalty\minusone}%
-       \fi
-       \hskip\d_page_sides_width\relax % \kern
-    %\else
-    %  we have a margin or edge float
-     \fi
+     \global\d_page_sides_vsize\d_page_sides_vsize_reset
+     \global\c_page_sides_n_of_lines\zerocount
    \fi}
 
-\def\page_sides_relocate_float#1%
-  {\global\setbox\floatbox\hpack
-     {\ifnum\c_page_sides_float_type=\plusfour
-        \kern\d_page_sides_leftshift
-      \else\ifnum\c_page_sides_float_type=\plusone
-        \kern\d_page_sides_leftshift
-      \fi\fi
-      \ifnum\c_page_sides_float_type>\plusfour
-        \kern-\d_page_sides_extrashift
-      \else
-        \kern\d_page_sides_shift
-      \fi
-      \vbox{#1\ifnum\c_page_sides_align=\plusfour \removedepth \fi}%
-      \ifnum\c_page_sides_float_type>\plusfour
-        \kern\d_page_sides_shift
-      \else
-        \kern-\d_page_sides_extrashift
-      \fi
-      \ifnum\c_page_sides_float_type=\pluseight
-        \kern\d_page_sides_rightshift
-      \else\ifnum\c_page_sides_float_type=\plusfive
-        \kern\d_page_sides_rightshift
-      \fi\fi}}
-
-\def\page_sides_apply_vertical_shift_normal
-  {\global\setbox\floatbox\hpack % why extra box
-     {\vpack
-        {\forgetall
-         \hsize\wd\floatbox
-         \vskip\privatescratchdimen
-         \offinterlineskip
-         \box\floatbox
-         % somehow we need this \scratchbox magic, but at least it's the same as the
-         % tracer now
-         \setbox\scratchbox\emptybox
-         \wd\scratchbox\hsize
-         \ht\scratchbox\d_page_sides_bottomtotal
-         \box\scratchbox
-         \vskip-\d_page_sides_bottomtotal
-         \ifnum\c_page_sides_align=\plusfive \vskip-\lineheight \fi}}}
-
-\def\page_sides_apply_vertical_shift_traced
-  {\global\setbox\floatbox\hpack % why extra box
-     {\backgroundline[trace:r]{\ruledhpack{\vpack
-        {\forgetall
-         \hsize\wd\floatbox
-         \vskip\privatescratchdimen
-         \offinterlineskip
-         \backgroundline[trace:g]{\ruledhpack{\box\floatbox}}\par
-         \blackrule[\c!color=trace:s,\c!height=\d_page_sides_bottomtotal,\c!depth=\zeropoint,\c!width=\hsize]%
-         \vskip-\d_page_sides_bottomtotal
-         \ifnum\c_page_sides_align=\plusfive \vskip-\lineheight \fi}}}}}
-
-\def\page_sides_apply_vertical_shift
-  {\ifnum\c_page_sides_align=\plusfour
-     \getnoflines{\ht\floatbox}%
-     \privatescratchdimen\dimexpr\noflines\lineheight-\strutdp\relax
-     \getrawnoflines\d_page_sides_toptotal
-     \advance\privatescratchdimen\noflines\lineheight
-     % todo: maybe rounding problem here
-     % \global\setbox\floatbox\hbox{\lower\lineheight\box\floatbox}%
-     \page_sides_force_depth
-     \ht\floatbox\privatescratchdimen
-     \dp\floatbox\zeropoint
-   \fi
-   \ifcase\c_page_sides_align \else
-     \global\d_page_sides_toptotal\zeropoint
-   \fi
-   \privatescratchdimen
-     \ifnum\c_page_sides_float_type<\plusfour
-       \d_page_sides_toptotal
-     \else\ifnum\c_page_sides_float_type>\plusfive
-       \d_page_sides_toptotal
-     \else
-       \zeropoint
-     \fi\fi
-   % the top of the box is at the previous baseline
-   \ifcase\c_page_sides_align
-       % 0 normal
-     \advance\privatescratchdimen\strutdp % or \openstrutdepth
-   \or % 1 height
-     \advance\privatescratchdimen\strutdp % or \openstrutdepth
-   \or % 2 line
-   \or % 3 depth
-     \advance\privatescratchdimen\lineheight % or \openlineheight
-     \advance\privatescratchdimen\strutdp    % or \openstrutdepth
-   \or % 4 grid
-     \privatescratchdimen\zeropoint
-   \or
-     \advance\privatescratchdimen\strutht % or \openstrutheight
-   \fi
-   % new
-   \global\c_page_sides_lines_done\zerocount
-   \ifnum\c_page_sides_n_of_lines>\zerocount
-     \advance\privatescratchdimen\c_page_sides_n_of_lines\lineheight
-   \fi
-   \iftracesidefloats
-     \page_sides_apply_vertical_shift_traced % uses \privatescratchdimen
-   \else
-     \page_sides_apply_vertical_shift_normal % uses \privatescratchdimen
-   \fi
-   \ifnum\c_page_sides_float_type<\plusfour
-     \global\d_page_sides_toptotal\zeropoint
-   \else\ifnum\c_page_sides_float_type>\plusfive
-     \global\d_page_sides_toptotal\zeropoint
-   \fi\fi
-   \global\d_page_sides_downshift\zeropoint}
-
 \def\page_sides_place_float
   {\ifnum\c_page_sides_float_type=\plusfour \kern\d_page_sides_toptotal \fi
    \ifnum\c_page_sides_float_type=\plusfive \kern\d_page_sides_toptotal \fi
-%    \d_page_sides_saved_depth\prevdepth
-%    \nointerlineskip
    \ifgridsnapping
      \page_sides_place_float_grid
    \else
@@ -540,10 +595,8 @@
    \fi
    \par
    \kern-\d_page_sides_height
-\vskip-\parskip
    \penalty10001 % oeps, this will change
-   \normalbaselines
-}%   \prevdepth\d_page_sides_saved_depth}
+   \normalbaselines}
 
 \def\page_sides_place_float_normal
   {\page_sides_push_float_inline\firstofoneargument}
@@ -556,7 +609,7 @@
    \ifx\p_grid\empty\else
      \snaptogrid[\p_grid]%
    \fi
-   \hbox{#1}}
+   \hpack{#1}}
 
 \def\page_sides_place_float_grid
   {\getrawnoflines\d_page_sides_height % raw ?
@@ -625,7 +678,15 @@
    \scratchdimenone\d_page_sides_vsize
    \scratchdimentwo\pagegoal
    \ifcase\c_page_sides_tolerance
-     \advance\scratchdimentwo -\strutdp
+     \ifcase\c_page_sides_method
+       % method 0 : raw
+     \or
+       % method 1 : safe (default)
+       \advance\scratchdimentwo -\strutdp
+     \or
+       % method 2 : tight (grid default)
+       \advance\scratchdimenone -\onepoint
+     \fi
    \or
      % tolerant
      \advance\scratchdimentwo -.5\strutdp
@@ -634,14 +695,13 @@
    \else
      \advance\scratchdimentwo -\strutdp
    \fi
-   % here also pagedepth
+   % how about \pagedepth
    \ifdim\scratchdimenone>\scratchdimentwo
      \global\setfalse\c_page_floats_room
    \else
      \ifdim\dimexpr\pagegoal-\d_page_sides_vsize\relax<\d_page_sides_bottomtotal
       % just weird: \global\advance\d_page_sides_vsize \scratchdimenone
        \global\settrue\c_page_sides_short
-       \page_otr_sides_push_penalties
        % why was this \global\holdinginserts\plusone
      \else
        \global\advance\d_page_sides_vsize \d_page_sides_bottomtotal % wins over inbetween
@@ -650,25 +710,15 @@
      \global\settrue\c_page_floats_room
    \fi}
 
-\def\page_sides_inject_before
-  {\checkedblank[\rootfloatparameter\c!spacebeforeside]}
-
-% \def\page_sides_inject_after
-%   {\checkedblank[\rootfloatparameter\c!spaceafterside]}
-%
-% As we have no clear end of one or more paragraphs this makes no sense so:
-
-\let\page_sides_inject_after\donothing
-
-% \def\page_sides_prepare_space
-%   {\inhibitblank} % hm, why here .. gets obscured anyway
+%D As we have no clear end of one or more paragraphs we only have pre float
+%D skips.
 
 \def\page_sides_handle_float#1% grid (4) is rather experimental
-  {\page_sides_check_skips
-   \page_sides_inject_before
-%    \page_sides_prepare_space
+  {\page_sides_check_horizontal_skips
+   \page_sides_check_vertical_skips
    \page_sides_apply_horizontal_shift
    \page_sides_check_previous_float
+   \page_sides_inject_before
    \page_sides_inject_dummy_lines
    \page_sides_relocate_float{#1}%
    \page_sides_apply_vertical_shift
@@ -676,11 +726,18 @@
    \ifconditional\c_page_floats_room \else
      \page_otr_fill_and_eject_page
      \page_sides_analyse_space
+    %\page_sides_inject_before
      \page_sides_inject_dummy_lines
    \fi
    \page_sides_place_float
    \page_sides_check_floats_reset
-   \ignorespaces} % not really needed
+   \page_sides_wrapup}
+
+\def\page_sides_wrapup
+  {% we need to do this aftergroup
+   \ignoreparskip \aftergroup\ignoreparskip
+   \ignorespaces  \aftergroup\ignorespaces
+   }
 
 \def\page_sides_check_floats_indeed
   {\page_sides_analyse_progress
@@ -689,49 +746,27 @@
    \else
      \page_sides_check_floats_reset
    \fi
-   \parskip\s_spac_whitespace_parskip}
+   \parskip\s_spac_whitespace_parskip} % not needed
 
 \let\page_sides_check_floats\page_sides_check_floats_indeed
 
 \unexpanded\def\page_sides_check_floats_tracer
   {\begingroup
-   \hskip-\d_page_sides_width % kern
-  %\llap{\smallinfofont\the\d_page_sides_progression\space=>\space\the\c_page_sides_n_of_hang\hskip.5\leftmargindistance}%
-   \color[trace:o]%
-     {\vrule\s!height.5\points\s!depth.5\points\s!width\d_page_sides_width
-      \llap{\showstruts\strut\kern.25\bodyfontsize}}%
+   \dontleavehmode
+   \ifnum\c_page_sides_float_type>\plusfour
+     \rlap
+       {\hskip\availablehsize % d_page_sides_width % kern
+        \color[trace:o]%
+          {\rlap{\kern.25\bodyfontsize\showstruts\strut}%
+           \vrule\s!height.5\points\s!depth.5\points\s!width\d_page_sides_width}}%
+   \else
+     \hskip-\d_page_sides_width % kern
+     \color[trace:o]%
+       {\vrule\s!height.5\points\s!depth.5\points\s!width\d_page_sides_width
+        \llap{\showstruts\strut\kern.25\bodyfontsize}}%
+   \fi
    \endgroup}
 
-% \usemodule[art-01]
-% \starttext
-%     \definemeasure[MyHeight][3cm] \definemeasure[MyWidth][3cm]
-%     \startbuffer
-%         \input klein \par
-%         \placefigure[left]{oeps}{\framed[width=\measure{MyWidth},height=\measure{MyHeight}]{}}
-%         \dorecurse{4}{test\par} \dorecurse{3}{\input klein }\par
-%         \placefigure[left]{oeps}{\framed[width=\measure{MyWidth},height=\measure{MyHeight}]{}}
-%         \dorecurse{3}{\input klein }\par
-%     \stopbuffer
-%     \enabletrackers[floats.anchoring]
-%     \setupfloats[step=small]
-%     \setupheadertexts[width=\measure{MyWidth},height=\measure{MyHeight}]
-%     \dostepwiserecurse {100} {120} {1} {
-%         \definemeasure[MyWidth][#1pt]
-%         \dostepwiserecurse {50} {300} {1} {
-%             \definemeasure[MyHeight][##1pt]
-%             \setupwhitespace[none]%
-%             \getbuffer \page
-%             \setupwhitespace[big]
-%             \getbuffer \page
-%         }
-%     }
-% \stoptext
-
-% \setupfloats
-%   [\c!sidethreshold=.5\strutdp] % set to "old" to check with old method
-
-\newdimen\d_page_sides_progression
-
 \unexpanded\def\page_sides_check_floats_set
   {\edef\p_sidethreshold{\floatparameter\c!sidethreshold}%
    \ifx\p_sidethreshold\v!old
@@ -749,7 +784,6 @@
      \c_page_sides_n_of_hang\noflines
    \fi
    \ifnum\c_page_sides_n_of_hang>\zerocount
-     % new from here (needs test case, old code)
      \ifcase\c_page_sides_n_of_lines
      \else
        \ifcase\c_page_sides_lines_done
@@ -760,33 +794,28 @@
          \global\advance\c_page_sides_n_of_lines-\privatescratchcounter
        \fi
      \fi
-     % hm, when do we get the parshape branch? needs testing
      \ifnum\c_page_sides_n_of_lines>\zerocount
        \privatescratchtoks\emptytoks
        \privatescratchcounter\c_page_sides_n_of_lines
        \privatescratchdimen\dimexpr\hsize-\d_page_sides_width\relax
        \dorecurse\c_page_sides_n_of_lines
-        %{\appendtoks \zeropoint \hsize \to \privatescratchtoks}%
          {\toksapp\privatescratchtoks{\zeropoint\hsize}}%
        \ifnum\c_page_sides_n_of_hang>\c_page_sides_n_of_lines
          \advance\c_page_sides_n_of_hang -\c_page_sides_n_of_lines\relax
          \advance\privatescratchcounter\c_page_sides_n_of_hang
          \dorecurse\c_page_sides_n_of_hang % weird, shouldn't that be scratchcounter
            {\ifnum\c_page_sides_float_type>\plusfour
-             %\appendtoks \zeropoint         \privatescratchdimen \to \privatescratchtoks
               \toksapp\privatescratchtoks{\zeropoint\privatescratchdimen}%
             \else
-             %\appendtoks \d_page_sides_width\privatescratchdimen \to \privatescratchtoks
               \toksapp\privatescratchtoks{\d_page_sides_width\privatescratchdimen}%
             \fi}%
        \fi
        \parshape
          \numexpr\privatescratchcounter+\plusone\relax
-         \the\privatescratchtoks  % \privatescratchcounter
-         \zeropoint \hsize % \plusone
+         \the\privatescratchtoks
+         \zeropoint \hsize
        \relax
      \else
-       % new till here
        \hangindent \ifnum\c_page_sides_float_type>\plusfour -\fi\d_page_sides_width
        \hangafter-\c_page_sides_n_of_hang
      \fi
@@ -815,51 +844,13 @@
      \fi
    \fi}
 
-\def\page_sides_inject_dummy_line_normal
-  {\hpack to \availablehsize{\strut\hss}}
-
-\def\page_sides_inject_dummy_line_traced
-  {\ruledhpack to \availablehsize{\backgroundline[trace:b]{\page_sides_inject_dummy_line_normal}}}
-
-\def\page_sides_inject_dummy_lines % so always one
-  {\ifconditional\c_page_sides_dummy_lines
-     \par
-     \page_sides_force_depth
-    %\checkedblank[\rootfloatparameter\c!sidespacebefore]%
-     \begingroup
-     \privatescratchcounter\pageshrink
-     \divide\privatescratchcounter \lineheight % \baselineskip
-     \advance\privatescratchcounter\plusone
-     \offinterlineskip
-     \ifcase\privatescratchcounter\else
-       \dorecurse\privatescratchcounter
-         {\dontleavehmode
-          \iftracesidefloats
-            \page_sides_inject_dummy_line_traced
-          \else
-            \page_sides_inject_dummy_line_normal
-          \fi
-          \par}%
-     \vskip-\lineheight
-     \vskip-\strutdp
-%        \blank[-\v!line]%
-     \fi
-     \endgroup
-   \else\ifdim\d_page_sides_midskip>\zeropoint\else
-%      \vskip\parskip
-     \ifdim\parskip>\zeropoint
-       \blank[\v!white]%
-     \fi
-   \fi\fi
-   \global\settrue\c_page_sides_dummy_lines}
-
-\def\adjustsidefloatdisplaylines % public, will change
-  {\aftergroup\page_sides_adjust_display_lines}
-
-\def\page_sides_adjust_display_lines
-  {\par
-   \noindent
-   \ignorespaces}
+% \def\adjustsidefloatdisplaylines % public, will change
+%   {\aftergroup\page_sides_adjust_display_lines}
+%
+% \def\page_sides_adjust_display_lines
+%   {\par
+%    \noindent
+%    \ignorespaces}
 
 %D We need to hook it into the other otr's. This code will be adapted once we rename
 %D the callers. We use \type {\def} as they can be redefined! Some will become obsolete
diff --git a/tex/context/base/mkiv/regi-ini.lua b/tex/context/base/mkiv/regi-ini.lua
index be8fa1b1c..7691e8765 100644
--- a/tex/context/base/mkiv/regi-ini.lua
+++ b/tex/context/base/mkiv/regi-ini.lua
@@ -12,6 +12,8 @@ if not modules then modules = { } end modules ['regi-ini'] = {
 runtime.</p>
 --ldx]]--
 
+-- Todo: use regi-imp*.lua instead
+
 local commands, context = commands, context
 
 local utfchar = utf.char
@@ -134,6 +136,9 @@ end
 setmetatableindex(mapping,    loadregime)
 setmetatableindex(backmapping,loadreverse)
 
+regimes.mapping     = mapping
+regimes.backmapping = backmapping
+
 local function fromregime(regime,line)
     if line and #line > 0 then
         local map = mapping[regime and synonyms[regime] or regime or currentregime]
@@ -251,6 +256,22 @@ end
 regimes.push = push
 regimes.pop  = pop
 
+function regimes.list()
+    local name = resolvers.findfile(format("regi-ini.lua",regime)) or ""
+    local okay = { }
+    if name then
+        local list = dir.glob(file.join(file.dirname(name),"regi-*.lua"))
+        for i=1,#list do
+            local name = list[i]
+            if name ~= "regi-ini.lua" then
+                okay[#okay+1] = match(name,"regi%-(.-)%.lua")
+            end
+            table.sort(okay)
+        end
+    end
+    return okay
+end
+
 if sequencers then
 
     sequencers.prependaction(textlineactions,"system","regimes.process")
diff --git a/tex/context/base/mkiv/spac-hor.mkiv b/tex/context/base/mkiv/spac-hor.mkiv
index 257535f73..176b52e1f 100644
--- a/tex/context/base/mkiv/spac-hor.mkiv
+++ b/tex/context/base/mkiv/spac-hor.mkiv
@@ -822,14 +822,16 @@
     \forgetbothskips
 \to \everyforgetall
 
-\unexpanded\def\forgetparskip
-  {\s_spac_whitespace_parskip\zeropoint
-   \parskip\zeropoint
-   \let\v_spac_whitespace_current\v!none}
-
-\appendtoks
-    \forgetparskip
-\to \everyforgetall
+% in spac-ver.mkiv
+%
+% \unexpanded\def\forgetparskip
+%   {\s_spac_whitespace_parskip\zeropoint
+%    \parskip\zeropoint
+%    \let\v_spac_whitespace_current\v!none}
+%
+% \appendtoks
+%     \forgetparskip
+% \to \everyforgetall
 
 %D Tolerance (can also be set with align):
 
diff --git a/tex/context/base/mkiv/spac-ver.lua b/tex/context/base/mkiv/spac-ver.lua
index 1cd78ce70..aee61adf9 100644
--- a/tex/context/base/mkiv/spac-ver.lua
+++ b/tex/context/base/mkiv/spac-ver.lua
@@ -40,7 +40,6 @@ local todimen = string.todimen
 local formatters = string.formatters
 
 local nodes        =  nodes
-local node         =  node
 local trackers     =  trackers
 local attributes   =  attributes
 local context      =  context
@@ -52,6 +51,7 @@ local texgetcount  = tex.getcount
 local texgetdimen  = tex.getdimen
 local texset       = tex.set
 local texsetdimen  = tex.setdimen
+local texsetcount  = tex.setcount
 local texnest      = tex.nest
 local texgetbox    = tex.getbox
 
@@ -149,6 +149,7 @@ local find_node_tail      = nuts.tail
 local flush_node          = nuts.flush_node
 local traverse_nodes      = nuts.traverse
 local traverse_nodes_id   = nuts.traverse_id
+local insert_node_after   = nuts.insert_after
 local insert_node_before  = nuts.insert_before
 local remove_node         = nuts.remove
 local count_nodes         = nuts.countall
@@ -694,41 +695,45 @@ local function snap_topskip(current,method)
     return w, 0
 end
 
-local categories = allocate {
-     [0] = 'discard',
-     [1] = 'largest',
-     [2] = 'force'  ,
-     [3] = 'penalty',
-     [4] = 'add'    ,
-     [5] = 'disable',
-     [6] = 'nowhite',
-     [7] = 'goback',
-     [8] = 'together', -- not used (?)
-     [9] = 'overlay',
-    [10] = 'notopskip',
-}
+do
 
-vspacing.categories = categories
+    local categories = allocate {
+         [0] = 'discard',
+         [1] = 'largest',
+         [2] = 'force'  ,
+         [3] = 'penalty',
+         [4] = 'add'    ,
+         [5] = 'disable',
+         [6] = 'nowhite',
+         [7] = 'goback',
+         [8] = 'together', -- not used (?)
+         [9] = 'overlay',
+        [10] = 'notopskip',
+    }
 
-function vspacing.tocategories(str)
-    local t = { }
-    for s in gmatch(str,"[^, ]") do -- use lpeg instead
-        local n = tonumber(s)
-        if n then
-            t[categories[n]] = true
-        else
-            t[b] = true
+    vspacing.categories = categories
+
+    function vspacing.tocategories(str)
+        local t = { }
+        for s in gmatch(str,"[^, ]") do -- use lpeg instead
+            local n = tonumber(s)
+            if n then
+                t[categories[n]] = true
+            else
+                t[b] = true
+            end
         end
+        return t
     end
-    return t
-end
 
-function vspacing.tocategory(str) -- can be optimized
-    if type(str) == "string" then
-        return set.tonumber(vspacing.tocategories(str))
-    else
-        return set.tonumber({ [categories[str]] = true })
+    function vspacing.tocategory(str) -- can be optimized
+        if type(str) == "string" then
+            return set.tonumber(vspacing.tocategories(str))
+        else
+            return set.tonumber({ [categories[str]] = true })
+        end
     end
+
 end
 
 vspacingdata.map  = vspacingdata.map  or { } -- allocate ?
@@ -1888,72 +1893,84 @@ end
 -- tex.lists.page_head
 -- tex.lists.contrib_head
 
-local stackhead, stacktail, stackhack = nil, nil, false
+do
 
-local function report(message,where,lst)
-    if lst and where then
-        report_vspacing(message,where,count_nodes(lst,true),nodeidstostring(lst))
-    else
-        report_vspacing(message,count_nodes(lst,true),nodeidstostring(lst))
+    local stackhead, stacktail, stackhack = nil, nil, false
+
+    local function report(message,where,lst)
+        if lst and where then
+            report_vspacing(message,where,count_nodes(lst,true),nodeidstostring(lst))
+        else
+            report_vspacing(message,count_nodes(lst,true),nodeidstostring(lst))
+        end
     end
-end
 
--- ugly code: we get partial lists (check if this stack is still okay) ... and we run
--- into temp nodes (sigh)
-
-function vspacing.pagehandler(newhead,where)
-    -- local newhead = texlists.contrib_head
-    if newhead then
-        newhead = tonut(newhead)
-        local newtail = find_node_tail(newhead) -- best pass that tail, known anyway
-        local flush = false
-        stackhack = true -- todo: only when grid snapping once enabled
-        -- todo: fast check if head = tail
-        for n in traverse_nodes(newhead) do -- we could just look for glue nodes
-            local id = getid(n)
-            if id ~= glue_code then
-                flush = true
-            elseif getsubtype(n) == userskip_code then
-                if getattr(n,a_skipcategory) then
-                    stackhack = true
-                else
+    -- ugly code: we get partial lists (check if this stack is still okay) ... and we run
+    -- into temp nodes (sigh)
+
+    function vspacing.pagehandler(newhead,where)
+        -- local newhead = texlists.contrib_head
+        if newhead then
+            newhead = tonut(newhead)
+            local newtail = find_node_tail(newhead) -- best pass that tail, known anyway
+            local flush = false
+            stackhack = true -- todo: only when grid snapping once enabled
+            -- todo: fast check if head = tail
+            for n in traverse_nodes(newhead) do -- we could just look for glue nodes
+                local id = getid(n)
+                if id ~= glue_code then
                     flush = true
+                else
+                    local subtype = getsubtype(n)
+                    if subtype == userskip_code then
+                        if getattr(n,a_skipcategory) then
+                            stackhack = true
+                        else
+                            flush = true
+                        end
+                    elseif subtype == parskip_code then
+                        -- if where == new_graf then ... end
+                        if texgetcount("c_spac_vspacing_ignore_parskip") > 0 then
+                            texsetcount("c_spac_vspacing_ignore_parskip",0)
+                            setglue(n)
+                         -- maybe removenode
+                        end
+                    end
                 end
-            else
-                -- tricky
             end
-        end
-        if flush then
-            if stackhead then
-                if trace_collect_vspacing then report("%s > appending %s nodes to stack (final): %s",where,newhead) end
-                setlink(stacktail,newhead)
-                newhead = stackhead
-                stackhead, stacktail = nil, nil
-            end
-            if stackhack then
-                stackhack = false
-                if trace_collect_vspacing then report("%s > processing %s nodes: %s",where,newhead) end
-             -- texlists.contrib_head = collapser(newhead,"page",where,trace_page_vspacing,true,a_snapmethod)
-                newhead = collapser(newhead,"page",where,trace_page_vspacing,true,a_snapmethod)
-            else
-                if trace_collect_vspacing then report("%s > flushing %s nodes: %s",where,newhead) end
-             -- texlists.contrib_head = newhead
-            end
-            return tonode(newhead)
-        else
-            if stackhead then
-                if trace_collect_vspacing then report("%s > appending %s nodes to stack (intermediate): %s",where,newhead) end
-                setlink(stacktail,newhead)
+            if flush then
+                if stackhead then
+                    if trace_collect_vspacing then report("%s > appending %s nodes to stack (final): %s",where,newhead) end
+                    setlink(stacktail,newhead)
+                    newhead = stackhead
+                    stackhead, stacktail = nil, nil
+                end
+                if stackhack then
+                    stackhack = false
+                    if trace_collect_vspacing then report("%s > processing %s nodes: %s",where,newhead) end
+                 -- texlists.contrib_head = collapser(newhead,"page",where,trace_page_vspacing,true,a_snapmethod)
+                    newhead = collapser(newhead,"page",where,trace_page_vspacing,true,a_snapmethod)
+                else
+                    if trace_collect_vspacing then report("%s > flushing %s nodes: %s",where,newhead) end
+                 -- texlists.contrib_head = newhead
+                end
+                return tonode(newhead)
             else
-                if trace_collect_vspacing then report("%s > storing %s nodes in stack (initial): %s",where,newhead) end
-                stackhead = newhead
+                if stackhead then
+                    if trace_collect_vspacing then report("%s > appending %s nodes to stack (intermediate): %s",where,newhead) end
+                    setlink(stacktail,newhead)
+                else
+                    if trace_collect_vspacing then report("%s > storing %s nodes in stack (initial): %s",where,newhead) end
+                    stackhead = newhead
+                end
+                stacktail = newtail
+             -- texlists.contrib_head = nil
+             -- newhead = nil
             end
-            stacktail = newtail
-         -- texlists.contrib_head = nil
-         -- newhead = nil
         end
+        return nil
     end
-    return nil
+
 end
 
 do
@@ -2033,16 +2050,37 @@ do
 
     trackers.register("vspacing.forcestrutdepth",function(v) trace = v end)
 
+--     function vspacing.forcestrutdepth(n,depth,trace_mode)
+--         local box = texgetbox(n)
+--         if box then
+--             box = tonut(box)
+--             local dp = getdepth(box)
+--             if dp < depth then
+--                 local head = getlist(box)
+--                 if head then
+--                     local tail = find_node_tail(head)
+--                     if tail and getid(tail) == hlist_code then
+--                         setdepth(tail,depth)
+--                         outer.prevdepth = depth
+--                         if trace or trace_mode > 0 then
+--                             nuts.setvisual(tail,"depth")
+--                         end
+--                     end
+--                 end
+--             end
+--         end
+--     end
+
     function vspacing.forcestrutdepth(n,depth,trace_mode)
         local box = texgetbox(n)
         if box then
             box = tonut(box)
-            local dp = getdepth(box)
-            if dp < depth then
-                local head = getlist(box)
-                if head then
-                    local tail = find_node_tail(head)
-                    if tail and getid(tail) == hlist_code then
+            local head = getlist(box)
+            if head then
+                local tail = find_node_tail(head)
+                if tail and getid(tail) == hlist_code then
+                    local dp = getdepth(tail)
+                    if dp < depth then
                         setdepth(tail,depth)
                         outer.prevdepth = depth
                         if trace or trace_mode > 0 then
diff --git a/tex/context/base/mkiv/spac-ver.mkiv b/tex/context/base/mkiv/spac-ver.mkiv
index 76ea35223..0927758c2 100644
--- a/tex/context/base/mkiv/spac-ver.mkiv
+++ b/tex/context/base/mkiv/spac-ver.mkiv
@@ -61,7 +61,7 @@
 
 \newif\iflocalinterlinespace
 
-\newskip\s_spac_vspacing_temp \s_spac_vspacing_temp\bigskipamount
+\newskip \s_spac_vspacing_temp \s_spac_vspacing_temp\bigskipamount
 
 \def\skipfactor    {.75}
 \def\skipgluefactor{.25}
@@ -2545,4 +2545,34 @@
 %      \blank[\ifx\p_before\empty\else\p_before,\fi\p_blank\ifx\p_after\empty\else,\p_after\fi]%
 %    \fi\fi}
 
+% \setupwhitespace[line]
+% \prerollblank[2*line]  \the\prerolledblank
+% \prerollblank[-2*line] \the\prerolledblank
+
+\newskip\prerolledblank
+
+\unexpanded\def\prerollblank[#1]%
+  {\begingroup
+   \edef\p_blank{#1}%
+   \ifx\p_blank\empty
+     \global\prerolledblank\zeropoint
+   \else\ifx\p_blank\v!none
+     \global\prerolledblank\zeropoint
+   \else
+     % don't mess with \arskip here!
+     \scratchskip\plusten\lineheight
+     \setbox\scratchbox\vbox
+       {\vskip\scratchskip
+        \kern\zeropoint
+        \blank[\p_blank]}%
+     % \dimexpr doesn't work well with skips
+     \advance\scratchskip-\ht\scratchbox
+     \global\prerolledblank-\scratchskip
+   \fi\fi
+   \endgroup}
+
+\newcount\c_spac_vspacing_ignore_parskip
+
+\unexpanded\def\ignoreparskip{\c_spac_vspacing_ignore_parskip\plusone}
+
 \protect \endinput
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index 09d1cb941..b5d8fd91c 100644
--- a/tex/context/base/mkiv/status-files.pdf
+++ b/tex/context/base/mkiv/status-files.pdf
diff --git a/tex/context/base/mkiv/status-lua.pdf b/tex/context/base/mkiv/status-lua.pdf
index c27899964..01bfb9e13 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkiv/strc-flt.mkvi b/tex/context/base/mkiv/strc-flt.mkvi
index 99ab2d50a..4c10e49e9 100644
--- a/tex/context/base/mkiv/strc-flt.mkvi
+++ b/tex/context/base/mkiv/strc-flt.mkvi
@@ -740,17 +740,27 @@
 \newdimen\d_strc_floats_top
 \newdimen\d_strc_floats_bottom
 
+% \def\strc_floats_calculate_skip#target#skip%
+%   {\begingroup
+%    \edef\askedfloatskip{\rootfloatparameter#skip}%
+%    \ifx\askedfloatskip\empty
+%      \global#target\zeropoint
+%    \else\ifx\askedfloatskip\v!none
+%      \global#target\zeropoint
+%    \else
+%      \setbox\scratchbox\vbox{\whitespace\blank[\askedfloatskip]}% todo: move whitespace inside blank
+%      \global#target\ht\scratchbox
+%    \fi\fi
+%    \endgroup}
+
 \def\strc_floats_calculate_skip#target#skip%
   {\begingroup
-   \edef\askedfloatskip{\rootfloatparameter#skip}%
-   \ifx\askedfloatskip\empty
-     \global#target\zeropoint
-   \else\ifx\askedfloatskip\v!none
-     \global#target\zeropoint
-   \else
-     \setbox\scratchbox\vbox{\whitespace\blank[\askedfloatskip]}% todo: move whitespace inside blank
-     \global#target\ht\scratchbox
-   \fi\fi
+   \edef\p_blank{\rootfloatparameter#skip}%
+   \ifx\p_blank\v!nowhite
+     \edef\p_blank{-\v!white}%
+   \fi
+   \prerollblank[\p_blank]%
+   \global#target\prerolledblank
    \endgroup}
 
 \def\strc_floats_analyze_variables_two
@@ -780,9 +790,11 @@
    \ifconditional\c_strc_floats_par_float
      \global\d_strc_floats_top        \zeropoint
      \global\d_strc_floats_bottom     \zeropoint
-     \strc_floats_calculate_skip\d_page_sides_topskip     \c!sidespacebefore
-     \strc_floats_calculate_skip\d_page_sides_bottomskip  \c!sidespaceafter
-     \strc_floats_calculate_skip\d_page_sides_midskip     \c!sidespaceinbetween
+     \strc_floats_calculate_skip\d_page_sides_topskip   \c!sidespacebefore
+     \strc_floats_calculate_skip\d_page_sides_bottomskip\c!sidespaceafter
+     \strc_floats_calculate_skip\d_page_sides_midskip   \c!sidespaceinbetween
+     \strc_floats_calculate_skip\d_strc_floats_top      \c!spacebeforeside
+     \strc_floats_calculate_skip\d_strc_floats_bottom   \c!spaceafterside
    \else
      \global\d_page_sides_topskip     \zeropoint
      \global\d_page_sides_bottomskip  \zeropoint
diff --git a/tex/context/base/mkiv/strc-ren.mkiv b/tex/context/base/mkiv/strc-ren.mkiv
index 90ad2252d..89aa6f55a 100644
--- a/tex/context/base/mkiv/strc-ren.mkiv
+++ b/tex/context/base/mkiv/strc-ren.mkiv
@@ -221,24 +221,6 @@
    \let\localheadsetup  \strc_rendering_initialize_spacing % historic name
    \let\headsetupspacing\strc_rendering_initialize_spacing}
 
-\def\strc_rendering_initialize_hsize_local
-  {\global\d_strc_rendering_local_leftoffset \leftskip
-   \global\d_strc_rendering_local_rightoffset\rightskip
- % \forgetall
- % \leftskip \d_strc_rendering_local_leftoffset  % no stretch
- % \rightskip\d_strc_rendering_local_rightoffset % no stretch
- % \setlocalhsize
- % \hsize\localhsize
- % \forgetbothskips}
-   \scratchwidth\availablehsize
-   \forgetall
-   \hsize\scratchwidth}
-
-\def\strc_rendering_initialize_hsize_global
-  {\global\d_strc_rendering_local_leftoffset \zeropoint
-   \global\d_strc_rendering_local_rightoffset\zeropoint
-   \forgetall}
-
 \def\strc_rendering_initialize_interaction
   {\resetinteractionparameter\c!style
    \resetinteractionparameter\c!color
@@ -308,73 +290,32 @@
       \d_strc_rendering_hang_height\zeropoint
     \fi}
 
-% \def\strc_rendering_stop_placement
-%   {\n_strc_rendering_hang_lines\zerocount
-%    \ifconditional\headisdisplay
-%      \strc_rendering_initialize_line_hang
-%      % kind of special, we want to snap heads also according to local specs local
-%      \ifgridsnapping
-%        \hbox\bgroup % extra hbox will trigger global snapper on top of local
-%          \edef\p_grid{\headparameter\c!grid}%
-%          \ifconditional\headisdisplay
-%            \ifx\p_grid\empty\else
-%              \useheadstyleandcolor\c!style\c!color
-%              \setupinterlinespace
-%              \useheadstyleandcolor\c!textstyle\c!textcolor
-%              \setupinterlinespace
-%            \fi
-%          \fi
-%          \snaptogrid[\p_grid]\hbox
-%            {\hskip\dimexpr\d_strc_rendering_local_leftoffset+\headparameter\c!margin\relax\box\b_strc_rendering_head}%
-%        \egroup
-%      \else
-%        \hbox
-%          {\hskip\dimexpr\d_strc_rendering_local_leftoffset+\headparameter\c!margin\relax\box\b_strc_rendering_head}%
-%      \fi
-%      \flushnotes % new, not really needed
-%      \endgraf
-%      \ifvmode
-%        \ifnum\n_strc_rendering_hang_lines>\zerocount
-%          \dorecurse\n_strc_rendering_hang_lines{\nointerlineskip\dosomebreak\nobreak\strut\endgraf}% to be checked
-%        \fi
-%        \nointerlineskip
-%        \dosomebreak\nobreak
-%      \fi
-%      \getheadsyncs
-%    \else
-%      % somehow this goes ok even when we push in the margin probably because we gobble pars
-%      % in the process of collecting index entries etc
-%      \strut
-%      \flushnotes % new, here since we're in par mode
-%      \unhbox\b_strc_rendering_head
-%      \getheadsyncs
-%      \ifconditional\headissomewhere
-%         % nothing special
-%      \else
-%       %\hskip\headnumberdistance\s!plus\headnumberdistance\s!minus.25\dimexpr\headnumberdistance\relax
-%        \hskip\headtextdistance\relax
-%        \strc_sectioning_inject_continuous_signal
-%      \fi
-%    \fi
-%    \ifconditional\headisdisplay
-%      \ifvmode
-%        \ifgridsnapping % important, font related depth, see comment
-%          \prevdepth\strutdp
-%        \else
-%          \prevdepth\d_strc_rendering_local_depth
-%        \fi
-%      \fi
-%    \fi
-%    \egroup
-%    \egroup
-%    \ifconditional\headisdisplay
-%      \useindentnextparameter\headparameter
-%    \else
-%      \nonoindentation % recently added, was a bug
-%    \fi}
+\def\strc_rendering_initialize_hsize_local
+  {\global\d_strc_rendering_local_leftoffset \leftskip
+   \global\d_strc_rendering_local_rightoffset\rightskip
+ % \forgetall
+ % \leftskip \d_strc_rendering_local_leftoffset  % no stretch
+ % \rightskip\d_strc_rendering_local_rightoffset % no stretch
+ % \setlocalhsize
+ % \hsize\localhsize
+ % \forgetbothskips}
+   \scratchwidth\availablehsize
+   \forgetall
+   \hsize\scratchwidth}
+
+\def\strc_rendering_initialize_hsize_global
+  {\global\d_strc_rendering_local_leftoffset \zeropoint
+   \global\d_strc_rendering_local_rightoffset\zeropoint
+   \forgetall}
+
+% \def\strc_sectioning_stay_on_this_line
+%   {\directcheckedvspacing{-\v!line,\v!samepage,\v!nowhite}%
+%    \directcheckedvspacing\v!disable}
+%
+% we now use \ignoreparskip, so:
 
 \def\strc_sectioning_stay_on_this_line
-  {\directcheckedvspacing{\v!samepage,-\v!line}%
+  {\directcheckedvspacing{-\v!line,\v!samepage}%
    \directcheckedvspacing\v!disable}
 
 \def\strc_rendering_stop_placement
@@ -434,7 +375,8 @@
    \ifconditional\headisdisplay
      \useindentnextparameter\headparameter
    \else
-     \nonoindentation % recently added, was a bug
+     \ignoreparskip
+     \noindentation % recently added, was a bug
    \fi}
 
 % nice testcase
diff --git a/tex/context/base/mkiv/strc-sec.mkiv b/tex/context/base/mkiv/strc-sec.mkiv
index 78421067e..4e5115a7d 100644
--- a/tex/context/base/mkiv/strc-sec.mkiv
+++ b/tex/context/base/mkiv/strc-sec.mkiv
@@ -1088,7 +1088,7 @@
   {\ifconditional\headisdisplay
      \ifconditional\c_strc_sectioning_auto_break
      % \vspacing[\v!samepage-\currentheadlevel]%
-\vspacing[\v!samepage]%
+       \vspacing[\v!samepage]%
      \fi
      \strc_sectioning_empty_correction
      \headparameter\c!after
diff --git a/tex/context/base/mkiv/util-sta.lua b/tex/context/base/mkiv/util-sta.lua
index 614ef567e..d140cacdc 100644
--- a/tex/context/base/mkiv/util-sta.lua
+++ b/tex/context/base/mkiv/util-sta.lua
@@ -154,7 +154,7 @@ function stacker.new(name)
     local function resolve_step(ti) -- keep track of changes outside function !
         -- todo: optimize for n=1 etc
         local result = nil
-        local noftop = #top
+        local noftop = top and #top or 0
         if ti > 0 then
             local current = list[ti]
             if current then