From 930a09233d5110b1c8c723293bfe29a98e76d304 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Thu, 12 Dec 2013 13:09:46 +1100
Subject: [PATCH] Bug 773296 - Part 25: Parse variable declarations in
 @supports conditions. r=dbaron

Since we cannot parse and discard a white space token after the ':' in a
custom property declaration, we instead explicitly skip over it when
parsing a non-custom property's value.
---
 layout/style/nsCSSParser.cpp | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 6f492706c3d..72219e9b725 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -3691,18 +3691,35 @@ CSSParserImpl::ParseSupportsConditionInParensInsideParens(bool& aConditionMet)
         return false;
       }
 
-      if (ExpectSymbol(')', true)) {
-        UngetToken();
-        return false;
-      }
-
       nsCSSProperty propID = nsCSSProps::LookupProperty(propertyName,
                                                         nsCSSProps::eEnabled);
       if (propID == eCSSProperty_UNKNOWN) {
+        if (ExpectSymbol(')', true)) {
+          UngetToken();
+          return false;
+        }
         aConditionMet = false;
         SkipUntil(')');
         UngetToken();
+      } else if (propID == eCSSPropertyExtra_variable) {
+        if (ExpectSymbol(')', false)) {
+          UngetToken();
+          return false;
+        }
+        CSSVariableDeclarations::Type variableType;
+        nsString variableValue;
+        aConditionMet =
+          ParseVariableDeclaration(&variableType, variableValue) &&
+          ParsePriority() != ePriority_Error;
+        if (!aConditionMet) {
+          SkipUntil(')');
+          UngetToken();
+        }
       } else {
+        if (ExpectSymbol(')', true)) {
+          UngetToken();
+          return false;
+        }
         aConditionMet = ParseProperty(propID) &&
                         ParsePriority() != ePriority_Error;
         if (!aConditionMet) {