From fb18d0e3a6e590c7f2a4aaed8bf33202a92dcfde Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 22:55:22 +0100
Subject: [PATCH 1/7] feat: add public code-window-auto-label attribute

Another filter can now ask for a window on a block that has no
filename, without copying the internal cw-auto marker. The label
frames the block even when auto-filename is off, and an explicit
filename or a per-block opt-out still wins.
---
 CHANGELOG.md                                  |  4 ++
 _extensions/code-window/_modules/language.lua | 22 +++++---
 _extensions/code-window/_schema.yml           |  3 ++
 _extensions/code-window/code-window.lua       | 20 ++++++--
 _extensions/code-window/main.lua              | 10 +++-
 docs/reference.qmd                            | 18 +++++++
 tests/fixtures/auto-label-forced.qmd          | 39 +++++++++++++++
 tests/fixtures/auto-label-kept.qmd            | 12 +++++
 tests/run.sh                                  | 50 +++++++++++++++++++
 9 files changed, 166 insertions(+), 12 deletions(-)
 create mode 100644 tests/fixtures/auto-label-forced.qmd
 create mode 100644 tests/fixtures/auto-label-kept.qmd

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9a926d5..66e1db1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,10 @@
 - refactor: Remove the `typst-title` hot-fix and its `hotfix.typst-title` option, as Quarto renders theorem titles as Typst markup since 1.10. (#78)
 - build: Require Quarto 1.10.19 or later. (#78)
 
+### New Features
+
+- feat: Add the `code-window-auto-label` attribute, so another filter can ask for a window with its own label on a block that has no `filename`. The label works even when `auto-filename` is off.
+
 ### Bug Fixes
 
 - fix: Style inline code in a Typst theorem title like inline code anywhere else. (#78)
diff --git a/_extensions/code-window/_modules/language.lua b/_extensions/code-window/_modules/language.lua
index 59bdeef..2494cf3 100644
--- a/_extensions/code-window/_modules/language.lua
+++ b/_extensions/code-window/_modules/language.lua
@@ -31,6 +31,20 @@ local function is_known_language(lang)
   return is_known
 end
 
+--- Write the label on a block that has no name yet.
+--- A filename or a label already on the block wins, because the author or
+--- another filter set it to name the window.
+--- @param block pandoc.CodeBlock
+--- @param label string Label to write when the block has no name yet
+local function set_label(block, label)
+  local attributes = block.attributes
+  local has_filename = attributes['filename'] and attributes['filename'] ~= ''
+  local has_label = attributes['code-window-auto-label'] and attributes['code-window-auto-label'] ~= ''
+  if not has_filename and not has_label then
+    attributes['code-window-auto-label'] = label
+  end
+end
+
 --- Normalise code blocks with no or unknown language class to "default".
 --- Both are framed like a highlighted code cell rather than left as a bare
 --- block: a no-language block is labelled "default", and an unknown language
@@ -47,18 +61,14 @@ function M.CodeBlock(block)
 
   if not block.classes or #block.classes == 0 then
     block.classes:insert('default')
-    if not block.attributes['filename'] or block.attributes['filename'] == '' then
-      block.attributes['code-window-auto-label'] = 'default'
-    end
+    set_label(block, 'default')
     return block
   end
 
   local lang = block.classes[1]
   if not is_known_language(lang) then
     block.classes[1] = 'default'
-    if not block.attributes['filename'] or block.attributes['filename'] == '' then
-      block.attributes['code-window-auto-label'] = lang
-    end
+    set_label(block, lang)
   end
 
   return block
diff --git a/_extensions/code-window/_schema.yml b/_extensions/code-window/_schema.yml
index 2484de6..4ac81e1 100644
--- a/_extensions/code-window/_schema.yml
+++ b/_extensions/code-window/_schema.yml
@@ -71,6 +71,9 @@ attributes:
       type: boolean
       default: false
       description: "Suppress the auto-generated filename for this specific code block without changing the global setting."
+    code-window-auto-label:
+      type: string
+      description: "Frame this code block with this label, styled as an auto-generated filename, even when auto-filename is false. An explicit filename, code-window-enabled false, or code-window-no-auto-filename true wins over it."
     code-window-style:
       type: string
       enum: ["default", "macos", "windows"]
diff --git a/_extensions/code-window/code-window.lua b/_extensions/code-window/code-window.lua
index 287fb33..fc2dd8d 100644
--- a/_extensions/code-window/code-window.lua
+++ b/_extensions/code-window/code-window.lua
@@ -147,6 +147,9 @@ end
 --- @return string|nil auto_label Label written by the language module, if any
 local function take_block_attributes(block)
   local auto_label = block.attributes['code-window-auto-label']
+  if auto_label == '' then
+    auto_label = nil
+  end
   local owned = {}
   for key, _ in pairs(block.attributes) do
     if key:sub(1, #ATTRIBUTE_PREFIX) == ATTRIBUTE_PREFIX and not cell_output.is_marker(key) then
@@ -706,7 +709,9 @@ local function process_html(block, resolved, auto_label)
     return block
   end
 
-  if not CONFIG.auto_filename or overrides.no_auto_filename then
+  -- A label on the block asks for a window by itself, so it does not wait on
+  -- the document's auto-filename setting.
+  if overrides.no_auto_filename or not (auto_label or CONFIG.auto_filename) then
     return block
   end
 
@@ -1036,10 +1041,15 @@ local function resolve_window_params(block, resolved, auto_label)
   local is_auto = false
 
   if (not filename or filename == '') and not overrides.no_auto_filename then
-    if CONFIG.auto_filename and block.classes and #block.classes > 0 then
-      -- Default/unknown/no-language blocks carry their label on
-      -- code-window-auto-label; everything else uses its language class.
-      filename = auto_label or block.classes[1]
+    -- A label on the block asks for a window by itself, whatever the
+    -- document's auto-filename setting. Default/unknown/no-language blocks
+    -- carry the label the language module wrote; everything else uses its
+    -- language class.
+    if auto_label then
+      filename = auto_label
+      is_auto = true
+    elseif CONFIG.auto_filename and block.classes and #block.classes > 0 then
+      filename = block.classes[1]
       is_auto = true
     end
   end
diff --git a/_extensions/code-window/main.lua b/_extensions/code-window/main.lua
index 59727d4..5af238e 100644
--- a/_extensions/code-window/main.lua
+++ b/_extensions/code-window/main.lua
@@ -79,10 +79,18 @@ end
 --- rewritten with no reader either. Answering that per block means relabelling
 --- where the name is built, which is a change to the two window paths rather
 --- than to this gate.
+--- A block that carries "code-window-auto-label" asks for a window by itself,
+--- so it takes the pass whatever "auto-filename" says. Without it, a block in
+--- a language Pandoc cannot highlight would get no wrapper to frame.
 --- @param block pandoc.CodeBlock
 --- @return pandoc.CodeBlock|nil Relabelled block, or nil when the pass is skipped
 local function normalise_language(block)
-  if not code_window.draws_chrome() or not code_window.CONFIG().auto_filename then
+  if not code_window.draws_chrome() then
+    return nil
+  end
+  local label = block.attributes['code-window-auto-label']
+  local has_label = label and label ~= ''
+  if not code_window.CONFIG().auto_filename and not has_label then
     return nil
   end
   return language.CodeBlock(block)
diff --git a/docs/reference.qmd b/docs/reference.qmd
index c560b9e..4e42542 100644
--- a/docs/reference.qmd
+++ b/docs/reference.qmd
@@ -47,6 +47,7 @@ extensions:
 | --- | --- | --- |
 | `code-window-enabled` | boolean | Whether this block gets chrome. Annotations still render when it does not. |
 | `code-window-no-auto-filename` | boolean | Suppress the derived filename for this block alone. |
+| `code-window-auto-label` | string | Frame this block with this label, styled as a derived filename. Works when `auto-filename` is `false`. |
 | `code-window-style` | string | Override the style for this block: `macos`, `windows`, `default`. |
 | `code-window-collapse` | boolean or string | Fold this block: `open`, `closed`, `true`, or `false`. HTML only. |
 | `code-window-lines` | string | The line spec shown in the chip, such as `1,3-5`. Defaults to Quarto's `code-line-numbers`. |
@@ -62,6 +63,23 @@ The result is the same window; it needs JavaScript, as the rest of the HTML chro
 Typst frames derived and author-set filenames alike, without a script.
 :::
 
+### Labels from another filter
+
+A filter that runs before Code Window can ask for a window on a block that has no `filename`.
+Set `code-window-auto-label` on the block to the label that the title bar must show.
+
+```lua
+block.attributes['code-window-auto-label'] = 'Terminal'
+```
+
+The label shows in the same style as a derived filename.
+The block gets the window also when the document sets `auto-filename` to `false`.
+These attributes win over the label:
+
+- A `filename` attribute names the window instead of the label.
+- `code-window-enabled="false"` removes the window.
+- `code-window-no-auto-filename="true"` removes the window.
+
 ## Executed cells
 
 Quarto writes the output of an executed cell as a code block with no language.
diff --git a/tests/fixtures/auto-label-forced.qmd b/tests/fixtures/auto-label-forced.qmd
new file mode 100644
index 0000000..5eafa63
--- /dev/null
+++ b/tests/fixtures/auto-label-forced.qmd
@@ -0,0 +1,39 @@
+---
+title: "A label that asks for its own window"
+filters:
+  - code-window
+format:
+  html: default
+  typst:
+    keep-typ: true
+extensions:
+  code-window:
+    auto-filename: false
+---
+
+The document derives no names, yet the first block names its own label, so it
+gets a window with that label. Each block after it writes something that wins
+over the label, so none of them gets the label in its title bar.
+
+```{.bash code-window-auto-label="Terminal"}
+echo forced
+```
+
+```{.bash filename="run.sh" code-window-auto-label="Terminal"}
+echo explicit
+```
+
+```{.bash code-window-enabled="false" code-window-auto-label="Terminal"}
+echo disabled
+```
+
+```{.bash code-window-no-auto-filename="true" code-window-auto-label="Terminal"}
+echo refused
+```
+
+A labelled block in a language Pandoc cannot highlight still goes through the
+language pass, so it is framed like any other labelled block.
+
+```{.foo code-window-auto-label="Shell"}
+x = 1
+```
diff --git a/tests/fixtures/auto-label-kept.qmd b/tests/fixtures/auto-label-kept.qmd
new file mode 100644
index 0000000..494459a
--- /dev/null
+++ b/tests/fixtures/auto-label-kept.qmd
@@ -0,0 +1,12 @@
+---
+title: "A label set before the language pass"
+filters:
+  - code-window
+---
+
+The language pass labels a block whose language Pandoc cannot highlight. A
+label another filter set first has to survive that pass.
+
+```{.foo code-window-auto-label="Terminal"}
+x = 1
+```
diff --git a/tests/run.sh b/tests/run.sh
index 05e1ebe..3ab341f 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -455,6 +455,56 @@ else
 		"pdftotext on PATH (brew install poppler)"
 fi
 
+# ============================================================================
+# A label set on a block asks for a window of its own
+# ============================================================================
+
+# Another filter sets code-window-auto-label to get a window with a derived
+# style on a block that names no file. The label has to work when the document
+# derives no names, and an explicit filename or a per-block opt-out still wins.
+render auto-label-forced html
+forced_html="${work_dir}/auto-label-forced.html"
+forced_labels="$({ grep -o 'data-filename="Terminal"' "${forced_html}" || true; } | wc -l | tr -d ' ')"
+forced_auto="$(block_classes "${forced_html}" | grep -c 'cw-auto' || true)"
+if [ "${forced_labels}" -eq 1 ] && [ "${forced_auto}" -eq 2 ] &&
+	grep -q 'data-filename="run.sh"' "${forced_html}"; then
+	report pass "auto-label-forced: only the labelled block takes the label in HTML"
+else
+	report fail "auto-label-forced: only the labelled block takes the label in HTML" \
+		"one data-filename=\"Terminal\", two cw-auto blocks, and data-filename=\"run.sh\", got ${forced_labels} and ${forced_auto}"
+fi
+
+render auto-label-forced typst
+forced_typst="${work_dir}/auto-label-forced.typ"
+if [ "$(count_typst_windows "${forced_typst}")" -eq 3 ] &&
+	grep -q '^#code-window(filename: "Terminal", is-auto: true' "${forced_typst}" &&
+	grep -q '^#code-window(filename: "run.sh", is-auto: false' "${forced_typst}"; then
+	report pass "auto-label-forced: only the labelled block takes the label in Typst"
+else
+	report fail "auto-label-forced: only the labelled block takes the label in Typst" \
+		"three code-window calls, with one for Terminal with is-auto: true and one for run.sh"
+fi
+
+# A labelled block takes the language pass even where the document derives no
+# names, or Pandoc leaves it unhighlighted and the script has no wrapper to
+# frame.
+if block_wrappers "${forced_html}" | grep -q 'data-filename="Shell"'; then
+	report pass "auto-label-forced: a labelled block in an unknown language is framed"
+else
+	report fail "auto-label-forced: a labelled block in an unknown language is framed" \
+		"data-filename=\"Shell\" on a sourceCode wrapper in auto-label-forced.html"
+fi
+
+# The language pass labels a block it cannot highlight, and a label that is
+# already there is the one to keep.
+render auto-label-kept html
+if grep -q 'data-filename="Terminal"' "${work_dir}/auto-label-kept.html"; then
+	report pass "auto-label-kept: the language pass keeps a label set before it"
+else
+	report fail "auto-label-kept: the language pass keeps a label set before it" \
+		"data-filename=\"Terminal\" in auto-label-kept.html"
+fi
+
 # ============================================================================
 
 printf '\n%s passed, %s failed\n' "${passed}" "${failed}"

From 5cb7675a03fac807fa5a3140d1a7852daf983379 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 22:59:26 +0100
Subject: [PATCH 2/7] refactor: read the auto label in one place

---
 _extensions/code-window/_modules/language.lua | 27 ++++++++++++-------
 _extensions/code-window/_schema.yml           |  2 +-
 _extensions/code-window/code-window.lua       | 13 +++------
 _extensions/code-window/main.lua              |  8 ++----
 tests/fixtures/auto-label-kept.qmd            | 12 ---------
 tests/run.sh                                  | 17 +++---------
 6 files changed, 27 insertions(+), 52 deletions(-)
 delete mode 100644 tests/fixtures/auto-label-kept.qmd

diff --git a/_extensions/code-window/_modules/language.lua b/_extensions/code-window/_modules/language.lua
index 2494cf3..d4763a7 100644
--- a/_extensions/code-window/_modules/language.lua
+++ b/_extensions/code-window/_modules/language.lua
@@ -6,6 +6,8 @@
 
 local cell_output = require(
   quarto.utils.resolve_path('_modules/cell-output.lua'):gsub('%.lua$', ''))
+local str = require(
+  quarto.utils.resolve_path('_vendor/quarto-lua-modules/string.lua'):gsub('%.lua$', ''))
 
 local M = {}
 
@@ -31,17 +33,24 @@ local function is_known_language(lang)
   return is_known
 end
 
---- Write the label on a block that has no name yet.
---- A filename or a label already on the block wins, because the author or
---- another filter set it to name the window.
+--- Read the label that names a block's window, set by this module, by the
+--- author, or by another filter. An empty value counts as no label.
 --- @param block pandoc.CodeBlock
---- @param label string Label to write when the block has no name yet
+--- @return string|nil label
+function M.auto_label(block)
+  local label = block.attributes['code-window-auto-label']
+  if str.is_empty(label) then
+    return nil
+  end
+  return label
+end
+
+--- Set the label unless the block already has a filename or a label.
+--- @param block pandoc.CodeBlock
+--- @param label string
 local function set_label(block, label)
-  local attributes = block.attributes
-  local has_filename = attributes['filename'] and attributes['filename'] ~= ''
-  local has_label = attributes['code-window-auto-label'] and attributes['code-window-auto-label'] ~= ''
-  if not has_filename and not has_label then
-    attributes['code-window-auto-label'] = label
+  if str.is_empty(block.attributes['filename']) and not M.auto_label(block) then
+    block.attributes['code-window-auto-label'] = label
   end
 end
 
diff --git a/_extensions/code-window/_schema.yml b/_extensions/code-window/_schema.yml
index 4ac81e1..34003e3 100644
--- a/_extensions/code-window/_schema.yml
+++ b/_extensions/code-window/_schema.yml
@@ -73,7 +73,7 @@ attributes:
       description: "Suppress the auto-generated filename for this specific code block without changing the global setting."
     code-window-auto-label:
       type: string
-      description: "Frame this code block with this label, styled as an auto-generated filename, even when auto-filename is false. An explicit filename, code-window-enabled false, or code-window-no-auto-filename true wins over it."
+      description: "Frame this code block with this label, styled as an auto-generated filename, even when auto-filename is false."
     code-window-style:
       type: string
       enum: ["default", "macos", "windows"]
diff --git a/_extensions/code-window/code-window.lua b/_extensions/code-window/code-window.lua
index fc2dd8d..b699279 100644
--- a/_extensions/code-window/code-window.lua
+++ b/_extensions/code-window/code-window.lua
@@ -18,6 +18,7 @@ local meta_mod = require(quarto.utils.resolve_path('_vendor/quarto-lua-modules/m
 local pdoc = require(quarto.utils.resolve_path('_vendor/quarto-lua-modules/pandoc-helpers.lua'):gsub('%.lua$', ''))
 local html_mod = require(quarto.utils.resolve_path('_vendor/quarto-lua-modules/html.lua'):gsub('%.lua$', ''))
 local cell_output = require(quarto.utils.resolve_path('_modules/cell-output.lua'):gsub('%.lua$', ''))
+local language = require(quarto.utils.resolve_path('_modules/language.lua'):gsub('%.lua$', ''))
 local code_annotations = nil
 local checker = nil
 
@@ -146,10 +147,7 @@ end
 --- @param block pandoc.CodeBlock Code block element
 --- @return string|nil auto_label Label written by the language module, if any
 local function take_block_attributes(block)
-  local auto_label = block.attributes['code-window-auto-label']
-  if auto_label == '' then
-    auto_label = nil
-  end
+  local auto_label = language.auto_label(block)
   local owned = {}
   for key, _ in pairs(block.attributes) do
     if key:sub(1, #ATTRIBUTE_PREFIX) == ATTRIBUTE_PREFIX and not cell_output.is_marker(key) then
@@ -709,8 +707,6 @@ local function process_html(block, resolved, auto_label)
     return block
   end
 
-  -- A label on the block asks for a window by itself, so it does not wait on
-  -- the document's auto-filename setting.
   if overrides.no_auto_filename or not (auto_label or CONFIG.auto_filename) then
     return block
   end
@@ -1041,10 +1037,7 @@ local function resolve_window_params(block, resolved, auto_label)
   local is_auto = false
 
   if (not filename or filename == '') and not overrides.no_auto_filename then
-    -- A label on the block asks for a window by itself, whatever the
-    -- document's auto-filename setting. Default/unknown/no-language blocks
-    -- carry the label the language module wrote; everything else uses its
-    -- language class.
+    -- A label asks for a window whatever auto-filename says.
     if auto_label then
       filename = auto_label
       is_auto = true
diff --git a/_extensions/code-window/main.lua b/_extensions/code-window/main.lua
index 5af238e..38357fe 100644
--- a/_extensions/code-window/main.lua
+++ b/_extensions/code-window/main.lua
@@ -85,12 +85,8 @@ end
 --- @param block pandoc.CodeBlock
 --- @return pandoc.CodeBlock|nil Relabelled block, or nil when the pass is skipped
 local function normalise_language(block)
-  if not code_window.draws_chrome() then
-    return nil
-  end
-  local label = block.attributes['code-window-auto-label']
-  local has_label = label and label ~= ''
-  if not code_window.CONFIG().auto_filename and not has_label then
+  if not code_window.draws_chrome()
+      or (not code_window.CONFIG().auto_filename and not language.auto_label(block)) then
     return nil
   end
   return language.CodeBlock(block)
diff --git a/tests/fixtures/auto-label-kept.qmd b/tests/fixtures/auto-label-kept.qmd
deleted file mode 100644
index 494459a..0000000
--- a/tests/fixtures/auto-label-kept.qmd
+++ /dev/null
@@ -1,12 +0,0 @@
----
-title: "A label set before the language pass"
-filters:
-  - code-window
----
-
-The language pass labels a block whose language Pandoc cannot highlight. A
-label another filter set first has to survive that pass.
-
-```{.foo code-window-auto-label="Terminal"}
-x = 1
-```
diff --git a/tests/run.sh b/tests/run.sh
index 3ab341f..9cf072c 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -464,7 +464,7 @@ fi
 # derives no names, and an explicit filename or a per-block opt-out still wins.
 render auto-label-forced html
 forced_html="${work_dir}/auto-label-forced.html"
-forced_labels="$({ grep -o 'data-filename="Terminal"' "${forced_html}" || true; } | wc -l | tr -d ' ')"
+forced_labels="$(block_wrappers "${forced_html}" | grep -c 'data-filename="Terminal"' || true)"
 forced_auto="$(block_classes "${forced_html}" | grep -c 'cw-auto' || true)"
 if [ "${forced_labels}" -eq 1 ] && [ "${forced_auto}" -eq 2 ] &&
 	grep -q 'data-filename="run.sh"' "${forced_html}"; then
@@ -485,9 +485,8 @@ else
 		"three code-window calls, with one for Terminal with is-auto: true and one for run.sh"
 fi
 
-# A labelled block takes the language pass even where the document derives no
-# names, or Pandoc leaves it unhighlighted and the script has no wrapper to
-# frame.
+# The language pass runs for a labelled block and keeps its label, or the
+# label would read "foo".
 if block_wrappers "${forced_html}" | grep -q 'data-filename="Shell"'; then
 	report pass "auto-label-forced: a labelled block in an unknown language is framed"
 else
@@ -495,16 +494,6 @@ else
 		"data-filename=\"Shell\" on a sourceCode wrapper in auto-label-forced.html"
 fi
 
-# The language pass labels a block it cannot highlight, and a label that is
-# already there is the one to keep.
-render auto-label-kept html
-if grep -q 'data-filename="Terminal"' "${work_dir}/auto-label-kept.html"; then
-	report pass "auto-label-kept: the language pass keeps a label set before it"
-else
-	report fail "auto-label-kept: the language pass keeps a label set before it" \
-		"data-filename=\"Terminal\" in auto-label-kept.html"
-fi
-
 # ============================================================================
 
 printf '\n%s passed, %s failed\n' "${passed}" "${failed}"

From 3fff1eedf63f08ea3a2fe95c3aac26ea9b2c1100 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 23:05:09 +0100
Subject: [PATCH 3/7] fix: keep the language of a labelled block with no window

---
 _extensions/code-window/main.lua     | 14 +++++++++++---
 tests/fixtures/auto-label-forced.qmd | 11 +++++++++++
 tests/run.sh                         | 10 ++++++++++
 3 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/_extensions/code-window/main.lua b/_extensions/code-window/main.lua
index 38357fe..e4ec16b 100644
--- a/_extensions/code-window/main.lua
+++ b/_extensions/code-window/main.lua
@@ -81,14 +81,22 @@ end
 --- than to this gate.
 --- A block that carries "code-window-auto-label" asks for a window by itself,
 --- so it takes the pass whatever "auto-filename" says. Without it, a block in
---- a language Pandoc cannot highlight would get no wrapper to frame.
+--- a language Pandoc cannot highlight would get no wrapper to frame. Such a
+--- block that also refuses the window has no reader for the label, so it is
+--- left alone here.
 --- @param block pandoc.CodeBlock
 --- @return pandoc.CodeBlock|nil Relabelled block, or nil when the pass is skipped
 local function normalise_language(block)
-  if not code_window.draws_chrome()
-      or (not code_window.CONFIG().auto_filename and not language.auto_label(block)) then
+  if not code_window.draws_chrome() then
     return nil
   end
+  if not code_window.CONFIG().auto_filename then
+    local refuses_window = block.attributes['code-window-enabled'] == 'false'
+      or block.attributes['code-window-no-auto-filename'] == 'true'
+    if not language.auto_label(block) or refuses_window then
+      return nil
+    end
+  end
   return language.CodeBlock(block)
 end
 
diff --git a/tests/fixtures/auto-label-forced.qmd b/tests/fixtures/auto-label-forced.qmd
index 5eafa63..a515453 100644
--- a/tests/fixtures/auto-label-forced.qmd
+++ b/tests/fixtures/auto-label-forced.qmd
@@ -37,3 +37,14 @@ language pass, so it is framed like any other labelled block.
 ```{.foo code-window-auto-label="Shell"}
 x = 1
 ```
+
+A labelled block that turns the window off keeps the language its author wrote,
+because no window reads the label.
+
+```{.foo code-window-no-auto-filename="true" code-window-auto-label="Terminal"}
+x = 2
+```
+
+```{.foo code-window-enabled="false" code-window-auto-label="Terminal"}
+x = 3
+```
diff --git a/tests/run.sh b/tests/run.sh
index 9cf072c..15b07c4 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -494,6 +494,16 @@ else
 		"data-filename=\"Shell\" on a sourceCode wrapper in auto-label-forced.html"
 fi
 
+# A labelled block that refuses the window has no reader for the label, so the
+# language pass leaves its language alone.
+opted_out="$(block_classes "${forced_html}" | grep -c '"foo' || true)"
+if [ "${opted_out}" -eq 2 ]; then
+	report pass "auto-label-forced: a labelled block that refuses the window keeps its language"
+else
+	report fail "auto-label-forced: a labelled block that refuses the window keeps its language" \
+		"two blocks with a foo class in auto-label-forced.html, got ${opted_out}"
+fi
+
 # ============================================================================
 
 printf '\n%s passed, %s failed\n' "${passed}" "${failed}"

From c6b5c4d2293874c8b673dbb76e79e300739ab695 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 23:10:04 +0100
Subject: [PATCH 4/7] fix: read a block's opt-out in any letter case

---
 _extensions/code-window/main.lua     | 5 +++--
 tests/fixtures/auto-label-forced.qmd | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/_extensions/code-window/main.lua b/_extensions/code-window/main.lua
index e4ec16b..478127f 100644
--- a/_extensions/code-window/main.lua
+++ b/_extensions/code-window/main.lua
@@ -91,8 +91,9 @@ local function normalise_language(block)
     return nil
   end
   if not code_window.CONFIG().auto_filename then
-    local refuses_window = block.attributes['code-window-enabled'] == 'false'
-      or block.attributes['code-window-no-auto-filename'] == 'true'
+    local enabled = (block.attributes['code-window-enabled'] or ''):lower()
+    local no_auto_filename = (block.attributes['code-window-no-auto-filename'] or ''):lower()
+    local refuses_window = enabled == 'false' or no_auto_filename == 'true'
     if not language.auto_label(block) or refuses_window then
       return nil
     end
diff --git a/tests/fixtures/auto-label-forced.qmd b/tests/fixtures/auto-label-forced.qmd
index a515453..48370eb 100644
--- a/tests/fixtures/auto-label-forced.qmd
+++ b/tests/fixtures/auto-label-forced.qmd
@@ -45,6 +45,6 @@ because no window reads the label.
 x = 2
 ```
 
-```{.foo code-window-enabled="false" code-window-auto-label="Terminal"}
+```{.foo code-window-enabled="False" code-window-auto-label="Terminal"}
 x = 3
 ```

From 1b971ad4d49f20d356d0fbe3203215efcc7ad5ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 23:14:42 +0100
Subject: [PATCH 5/7] docs: note why the language gate reads raw opt-outs

---
 _extensions/code-window/main.lua | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/_extensions/code-window/main.lua b/_extensions/code-window/main.lua
index 478127f..77cbe79 100644
--- a/_extensions/code-window/main.lua
+++ b/_extensions/code-window/main.lua
@@ -91,6 +91,8 @@ local function normalise_language(block)
     return nil
   end
   if not code_window.CONFIG().auto_filename then
+    -- Lowercased to match the schema's boolean coercion. Resolving through the
+    -- schema check here would report each of its warnings twice per block.
     local enabled = (block.attributes['code-window-enabled'] or ''):lower()
     local no_auto_filename = (block.attributes['code-window-no-auto-filename'] or ''):lower()
     local refuses_window = enabled == 'false' or no_auto_filename == 'true'

From 9e252af815e2383669ab35cd24918cc8253208ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 23:16:06 +0100
Subject: [PATCH 6/7] docs: list the auto label under Unreleased

---
 CHANGELOG.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 66e1db1..a01d7bd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### New Features
+
+- feat: Add the `code-window-auto-label` attribute, so another filter can ask for a window with its own label on a block that has no `filename`. The label works even when `auto-filename` is off.
+
 ## 1.7.0 (2026-11-04)
 
 ### Breaking Changes
@@ -9,10 +13,6 @@
 - refactor: Remove the `typst-title` hot-fix and its `hotfix.typst-title` option, as Quarto renders theorem titles as Typst markup since 1.10. (#78)
 - build: Require Quarto 1.10.19 or later. (#78)
 
-### New Features
-
-- feat: Add the `code-window-auto-label` attribute, so another filter can ask for a window with its own label on a block that has no `filename`. The label works even when `auto-filename` is off.
-
 ### Bug Fixes
 
 - fix: Style inline code in a Typst theorem title like inline code anywhere else. (#78)

From 856c7c85132f05644f758126701c64d685e35b54 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Canouil?=
 <8896044+mcanouil@users.noreply.github.com>
Date: Wed, 4 Nov 2026 23:16:38 +0100
Subject: [PATCH 7/7] docs: add the pull request to the changelog [skip ci]

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a01d7bd..165a998 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@
 
 ### New Features
 
-- feat: Add the `code-window-auto-label` attribute, so another filter can ask for a window with its own label on a block that has no `filename`. The label works even when `auto-filename` is off.
+- feat: Add the `code-window-auto-label` attribute, so another filter can ask for a window with its own label on a block that has no `filename`. The label works even when `auto-filename` is off. (#82)
 
 ## 1.7.0 (2026-11-04)