Fix meta shortcode not preserving line breaks in values (#14061) (#14073)

The meta shortcode handler previously used processValue() for all
contexts, which collapses multi-line metadata into inline content.
Now handleMeta() dispatches based on context: block context returns
Blocks directly via processValueInBlockContext(), inline context
preserves the existing behavior, and text context (e.g. inside code
blocks) writes blocks back as markdown to preserve structure.

Closes #14061

Co-authored-by: Claude Opus 4.6 <[email protected]>

Author: cscheid

news/changelog-1.9.md

@@ -3,6 +3,7 @@ All changes included in 1.9:
 ## Shortcodes
 
 - ([#13342](https://github.com/quarto-dev/quarto-cli/issues/13342)): Ensure that the `contents` shortcode works inside metadata.
+- ([#14061](https://github.com/quarto-dev/quarto-cli/issues/14061)): Fix `meta` shortcode not preserving line breaks in values. The shortcode now respects its usage context (block, inline, or text) and preserves paragraph breaks in block and code block contexts.
 
 ## Regression fixes
 

src/resources/filters/quarto-pre/shortcodes-handlers.lua

@@ -251,12 +251,32 @@ function handleMeta(args, _kwargs, _meta, _raw_args, context)
 
     -- read the option value
     local optionValue = option(varName, nil)
-    if optionValue ~= nil then
-      return processValue(optionValue, varName, "meta")
-    else 
+    if optionValue == nil then
       warn("Unknown meta key " .. varName .. " specified in a metadata Shortcode.")
       return { pandoc.Strong(pandoc.Inlines {pandoc.Str("?meta:" .. varName)}) } 
     end
+
+    if context == "block" then
+      return processValueInBlockContext(optionValue, varName, "meta")
+    elseif context == "inline" then
+      return processValue(optionValue, varName, "meta")
+    elseif context == "text" then
+      -- As a special case, we treat the result of using
+      --
+      -- key2: '`Str "Something *with* a _line_ break\n\nI want to preserve"`{=pandoc-native}'
+      --
+      -- differently to allow users to specify precisely the
+      -- string they want to use.
+      if type(optionValue) == "table" and #optionValue > 0 and optionValue[1].t == "Str" then
+        return optionValue[1].text
+      else
+        local blocks = pandoc.Blocks(optionValue)
+        return pandoc.write(pandoc.Pandoc(blocks), "markdown")
+      end
+    else
+      internal_error("Unknown context " .. context)
+      return nil
+    end
   else
     -- no args, we can't do anything
     return nil
@@ -306,6 +326,25 @@ function processValue(val, name, t)
   end
 end
 
+function processValueInBlockContext(val, name, t)    
+  if type(val) == "table" then
+    if #val == 0 then
+      return { pandoc.Str( "") }
+    end
+    local pt = pandoc.utils.type(val)
+    if pt == "Inlines" or pt == "Blocks" then
+      return val
+    elseif pt == "List" and #val == 1 then
+      return processValueInBlockContext(val[1], name, t)
+    else
+      warn("Unsupported type '" .. pandoc.utils.type(val)  .. "' for key " .. name .. " in a " .. t .. " shortcode.")
+      return { pandoc.Strong(pandoc.Inlines { pandoc.Str("?invalid " .. t .. " type:" .. name) } ) }
+    end
+  else 
+    return { pandoc.Str( tostring(val) ) }
+  end
+end
+
 
 function handlePagebreak()
 

tests/docs/smoke-all/2026/02/20/14061.qmd

@@ -0,0 +1,22 @@
+---
+format: html
+key: |
+  Something with a line break
+
+  I want to preserve.
+_quarto:
+  tests:
+    html:
+      ensureFileRegexMatches:
+        -
+          - "Something with a line break"
+          - "I want to preserve"
+        -
+          - "line break I want"
+---
+
+``` yaml
+{{< meta key >}}
+```
+
+{{< meta key >}}