Issue #1994 - Align CSS.supports with the current spec.

The current spec makes "implicit" parentheses a thing for feeding
css strings to CSS.supports()
The current spec also implies CSS is a namespace, not an interface

6 files changed, 35 insertions, 27 deletions

diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index 989757548a..146bf8d15b 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -170,10 +170,6 @@ DOMInterfaces = {
     'headerFile': 'Crypto.h'
 },
 
-'CSS': {
-    'concrete': False,
-},
-
 'CSS2Properties': {
     'nativeType': 'nsDOMCSSDeclaration'
 },
diff --git a/dom/webidl/CSS.webidl b/dom/webidl/CSS.webidl
index b5cdab2d18..2a9746e2c9 100644
--- a/dom/webidl/CSS.webidl
+++ b/dom/webidl/CSS.webidl
@@ -10,15 +10,15 @@
  * liability, trademark and document use rules apply.
  */
 
-interface CSS {
+namespace CSS {
   [Throws]
-  static boolean supports(DOMString property, DOMString value);
+  boolean supports(DOMString property, DOMString value);
 
   [Throws]
-  static boolean supports(DOMString conditionText);
+  boolean supports(DOMString conditionText);
 };
 
 // http://dev.w3.org/csswg/cssom/#the-css.escape%28%29-method
-partial interface CSS {
-  static DOMString escape(DOMString ident);
+partial namespace CSS {
+  DOMString escape(DOMString ident);
 };
diff --git a/layout/style/CSS.cpp b/layout/style/CSS.cpp
index b70f67a505..1078945ee5 100644
--- a/layout/style/CSS.cpp
+++ b/layout/style/CSS.cpp
@@ -62,12 +62,6 @@ CSS::Supports(const GlobalObject& aGlobal,
     return false;
   }
 
-  if (info.mStyleBackendType == StyleBackendType::Servo) {
-    NS_ConvertUTF16toUTF8 property(aProperty);
-    NS_ConvertUTF16toUTF8 value(aValue);
-    return Servo_CSSSupports(&property, &value);
-  }
-
   nsCSSParser parser;
   return parser.EvaluateSupportsDeclaration(aProperty, aValue, info.mDocURI,
                                             info.mBaseURI, info.mPrincipal);
@@ -86,13 +80,10 @@ CSS::Supports(const GlobalObject& aGlobal,
     return false;
   }
 
-  if (info.mStyleBackendType == StyleBackendType::Servo) {
-    MOZ_CRASH("stylo: CSS.supports() with arguments is not yet implemented");
-  }
-
   nsCSSParser parser;
   return parser.EvaluateSupportsCondition(aCondition, info.mDocURI,
-                                          info.mBaseURI, info.mPrincipal);
+                                          info.mBaseURI, info.mPrincipal,
+                                          css::SupportsParsingSettings::ImpliedParentheses);
 }
 
 /* static */ void
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 6a65f06646..b981a553f3 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -257,7 +257,8 @@ public:
   bool EvaluateSupportsCondition(const nsAString& aCondition,
                                  nsIURI* aDocURL,
                                  nsIURI* aBaseURL,
-                                 nsIPrincipal* aDocPrincipal);
+                                 nsIPrincipal* aDocPrincipal,
+                                 SupportsParsingSettings aSettings = SupportsParsingSettings::Normal);
 
   bool ParseCounterStyleName(const nsAString& aBuffer,
                              nsIURI* aURL,
@@ -2457,7 +2458,8 @@ bool
 CSSParserImpl::EvaluateSupportsCondition(const nsAString& aDeclaration,
                                          nsIURI* aDocURL,
                                          nsIURI* aBaseURL,
-                                         nsIPrincipal* aDocPrincipal)
+                                         nsIPrincipal* aDocPrincipal,
+                                         SupportsParsingSettings aSettings)
 {
   nsCSSScanner scanner(aDeclaration, 0);
   css::ErrorReporter reporter(scanner, mSheet, mChildLoader, aDocURL);
@@ -2465,7 +2467,13 @@ CSSParserImpl::EvaluateSupportsCondition(const nsAString& aDeclaration,
   nsAutoSuppressErrors suppressErrors(this);
 
   bool conditionMet;
-  bool parsedOK = ParseSupportsCondition(conditionMet) && !GetToken(true);
+  bool parsedOK;
+
+  if (aSettings == SupportsParsingSettings::ImpliedParentheses) {
+    parsedOK = ParseSupportsConditionInParensInsideParens(conditionMet) && !GetToken(true);
+  } else {
+    parsedOK = ParseSupportsCondition(conditionMet) && !GetToken(true);
+  }
 
   CLEAR_ERROR();
   ReleaseScanner();
@@ -18245,10 +18253,11 @@ bool
 nsCSSParser::EvaluateSupportsCondition(const nsAString& aCondition,
                                        nsIURI* aDocURL,
                                        nsIURI* aBaseURL,
-                                       nsIPrincipal* aDocPrincipal)
+                                       nsIPrincipal* aDocPrincipal,
+                                       SupportsParsingSettings aSettings)
 {
   return static_cast<CSSParserImpl*>(mImpl)->
-    EvaluateSupportsCondition(aCondition, aDocURL, aBaseURL, aDocPrincipal);
+    EvaluateSupportsCondition(aCondition, aDocURL, aBaseURL, aDocPrincipal, aSettings);
 }
 
 bool
diff --git a/layout/style/nsCSSParser.h b/layout/style/nsCSSParser.h
index 37cd325f20..e3d526659d 100644
--- a/layout/style/nsCSSParser.h
+++ b/layout/style/nsCSSParser.h
@@ -34,6 +34,12 @@ namespace css {
 class Rule;
 class Declaration;
 class StyleRule;
+
+enum class SupportsParsingSettings {
+  Normal,
+  ImpliedParentheses
+};
+
 } // namespace css
 } // namespace mozilla
 
@@ -257,11 +263,17 @@ public:
   /**
    * Parse an @supports condition and returns the result of evaluating the
    * condition.
+   *
+   * The one-argument CSS.supports() allows for providing an @supports condition
+   * without parentheses, i.e. the parentheses are "implied". In such a case,
+   * aSettings can be set to ImpliedParentheses.
    */
   bool EvaluateSupportsCondition(const nsAString& aCondition,
                                  nsIURI* aDocURL,
                                  nsIURI* aBaseURL,
-                                 nsIPrincipal* aDocPrincipal);
+                                 nsIPrincipal* aDocPrincipal,
+                                 mozilla::css::SupportsParsingSettings aSettings
+                                   = mozilla::css::SupportsParsingSettings::Normal);
 
   typedef void (*VariableEnumFunc)(const nsAString&, void*);
 
diff --git a/layout/style/test/test_css_supports.html b/layout/style/test/test_css_supports.html
index fa5b3fdcba..a500a3798b 100644
--- a/layout/style/test/test_css_supports.html
+++ b/layout/style/test/test_css_supports.html
@@ -22,6 +22,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=779917
 function runTest()
 {
   var passingConditions = [
+    "color: green",
     "(color: green)",
     "((color: green))",
     "(color: green !important)",
@@ -69,7 +70,6 @@ function runTest()
     "(color: green) or an-extension(that is [unbalanced)",
     "not(unknown: unknown)",
     "(color: green) or(color: blue)",
-    "color: green",
     "(color: green;)",
     "(font-family: 'Helvetica\n",
     "(font-family: 'Helvetica\n')",