Update manfilter for greater portability.

The tables in our man pages were not rendering correctly
with mandoc, now used by default with macOS. mandoc doesn't
allow man formatting inside table cells.

For maximal portability, we now render the tables in plain
format and include them as code blocks in the man page.

Closes #8045.

1 files changed, 18 insertions, 20 deletions

diff --git a/man/manfilter.lua b/man/manfilter.lua
index dd1a9ab56..6abd950fc 100644
--- a/man/manfilter.lua
+++ b/man/manfilter.lua
@@ -11,27 +11,25 @@ function Header(el)
     end
 end
 
--- unindent table content
+-- For portability with mandoc, which doesn't allow man commands
+-- inside table cells, we convert all tables to code blocks.
 function Table(el)
-  for _,body in ipairs(el.bodies) do
-    handleTableBody(body)
-  end
-  return el
-end
-
-local function handleCell(el)
-  if #el.contents > 0 and el.contents[1].t == "CodeBlock" then
-    table.insert(el.contents, 1, pandoc.RawBlock("man", ".RS -14n"))
-    table.insert(el.contents, pandoc.RawBlock("man", ".RE"))
-  end
-end
-
-function handleTableBody(el)
-  for _,row in ipairs(el.body) do
-    for _,cell in ipairs(row.cells) do
-      handleCell(cell)
-    end
-  end
+  local rendered = pandoc.write(pandoc.Pandoc({el}), "plain")
+  local adjusted = rendered  -- tame grid table lines
+                     :gsub("%+([=:][=:]+)",
+                       function(s)
+                         return " " .. string.rep("-", #s - 1)
+                       end)
+                     :gsub("(%+[-:][-:]+)",
+                       function(s)
+                         return ""
+                       end)
+                     :gsub("%+\n","\n")
+                     :gsub("\n|    ","\n|")
+                     :gsub("|","")
+  return { pandoc.RawBlock("man", ".RS -14n"),
+           pandoc.CodeBlock(adjusted),
+           pandoc.RawBlock("man", ".RE") }
 end