From 0e554ab600274a93155b5e2801f66aaf8cd073e8 Mon Sep 17 00:00:00 2001
From: Romain Menke <romainmenke@gmail.com>
Date: Wed, 26 Nov 2025 13:29:59 +0100
Subject: [PATCH] css-syntax-patches-for-csstree: patch calc-size

---
 .../CHANGELOG.md                              |  5 ++++
 .../dist/index.json                           |  4 ++--
 .../patches/webref-over-csstree-types.json    | 24 +++++++++++++++----
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/packages/css-syntax-patches-for-csstree/CHANGELOG.md b/packages/css-syntax-patches-for-csstree/CHANGELOG.md
index 24cca8ae46..5bd9c744be 100644
--- a/packages/css-syntax-patches-for-csstree/CHANGELOG.md
+++ b/packages/css-syntax-patches-for-csstree/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changes to CSS Syntax Patches For CSSTree
 
+### Unreleased (patch)
+
+- Patch `calc-size()` to allow the `size` keyword
+
+
 ### 1.0.18
 
 _November 26, 2025_
diff --git a/packages/css-syntax-patches-for-csstree/dist/index.json b/packages/css-syntax-patches-for-csstree/dist/index.json
index d9210ade06..82f478eb0d 100644
--- a/packages/css-syntax-patches-for-csstree/dist/index.json
+++ b/packages/css-syntax-patches-for-csstree/dist/index.json
@@ -546,8 +546,8 @@
 			"calc-keyword": "e | pi | infinity | -infinity | NaN",
 			"calc-mix()": "calc-mix( [ <calc-sum> <percentage [0,100]>? ]# )",
 			"calc-product": "<calc-value> [ [ '*' | / ] <calc-value> ]*",
-			"calc-size-basis": "[ <size-keyword> | <calc-size()> | any | <calc-sum> ]",
-			"calc-size()": "calc-size( <calc-size-basis> , <calc-sum> )",
+			"calc-size-basis": "[ <size-keyword> | <calc-size()> | <calc-sum> ]",
+			"calc-size()": "calc-size( [ [ <calc-size-basis> , [ <calc-sum> | size ] ] | [ any , <calc-sum> ] ] )",
 			"calc-value": "<number> | <dimension> | <percentage> | <calc-keyword> | ( <calc-sum> )",
 			"cf-image": "[ <image> | <color> ] && <percentage [0,100]>?",
 			"circle()": "circle( <radial-size>? [ at <position> ]? )",
diff --git a/packages/css-syntax-patches-for-csstree/patches/webref-over-csstree-types.json b/packages/css-syntax-patches-for-csstree/patches/webref-over-csstree-types.json
index 795b1db465..700e1d8a05 100644
--- a/packages/css-syntax-patches-for-csstree/patches/webref-over-csstree-types.json
+++ b/packages/css-syntax-patches-for-csstree/patches/webref-over-csstree-types.json
@@ -737,7 +737,7 @@
 		"comment": "",
 		"syntax-b": "",
 		"syntax-a": "[ <size-keyword> | <calc-size()> | any | <calc-sum> ]",
-		"syntax-m": "[ <size-keyword> | <calc-size()> | any | <calc-sum> ]",
+		"syntax-m": "[ <size-keyword> | <calc-size()> | <calc-sum> ]",
 		"tests": {
 			"passing": [],
 			"failing": []
@@ -745,13 +745,27 @@
 	},
 	"calc-size()": {
 		"type": "added",
-		"comment": "",
+		"comment": "https://github.com/w3c/csswg-drafts/issues/13158",
 		"syntax-b": "",
 		"syntax-a": "calc-size( <calc-size-basis> , <calc-sum> )",
-		"syntax-m": "calc-size( <calc-size-basis> , <calc-sum> )",
+		"syntax-m": "calc-size( [ [ <calc-size-basis> , [ <calc-sum> | size ] ] | [ any , <calc-sum> ] ] )",
 		"tests": {
-			"passing": [],
-			"failing": []
+			"passing": [
+				{
+					"property": "height",
+					"value": "calc-size(auto, size)"
+				},
+				{
+					"property": "height",
+					"value": "calc-size(auto, 10px)"
+				}
+			],
+			"failing": [
+				{
+					"property": "height",
+					"value": "calc-size(any, size)"
+				}
+			]
 		}
 	},
 	"calc-value": {