Do not preserve trailing spaces when testing ConTeXt

markdown.dtx

@@ -33405,9 +33405,11 @@ end
 % \end{markdown}
 %  \begin{macrocode}
 \startluacode
-  document.markdown_buffering = false
+  document.markdown_preserve_trailing_spaces = true
+  document.markdown_is_buffering = false
   local function preserve_trailing_spaces(line)
-    if document.markdown_buffering then
+    if document.markdown_is_buffering and
+       document.markdown_preserve_trailing_spaces then
       line = line:gsub("[ \t][ \t]$", "\t\t")
     end
     return line
@@ -33418,11 +33420,11 @@ end
   \catcode`\|=0%
   \catcode`\\=12%
   |gdef|startmarkdown{%
-    |ctxlua{document.markdown_buffering = true}%
+    |ctxlua{document.markdown_is_buffering = true}%
     |markdownReadAndConvert{\stopmarkdown}%
                            {|stopmarkdown}}%
   |gdef|stopmarkdown{%
-    |ctxlua{document.markdown_buffering = false}%
+    |ctxlua{document.markdown_is_buffering = false}%
     |markdownEnd}%
 |endgroup
 %    \end{macrocode}

tests/templates/context-mkiv/verbatim/body.tex.m4

@@ -4,6 +4,8 @@
 % Prevent the folding of characters into a single space token in logs.
 \catcode"09=12%  Tabs (U+0009)
 \catcode"20=12%  Spaces (U+0020)
+% Do not preserve trailing spaces in input buffer for parity with other TeX formats.
+\ctxlua{document.markdown_preserve_trailing_spaces = false}
 % Disable active characters of the TeX engine.
 \catcode"7E=12%  Tildes (U+007E)
 \catcode"7C=12%  Pipes (U+007C)