Bug 512908 - Don't expose empty live attribute if there is no aria-live and ARIA role hasn't default live value, r=marcoz, davidb

accessible/src/base/nsAccUtils.cpp

@@ -706,17 +706,19 @@ nsAccUtils::GetAttributeCharacteristics(nsIAtom* aAtom)
     return 0;
 }
 
-void
+PRBool
 nsAccUtils::GetLiveAttrValue(PRUint32 aRule, nsAString& aValue)
 {
   switch (aRule) {
     case eOffLiveAttr:
       aValue = NS_LITERAL_STRING("off");
-      break;
+      return PR_TRUE;
     case ePoliteLiveAttr:
       aValue = NS_LITERAL_STRING("polite");
-      break;
+      return PR_TRUE;
   }
+
+  return PR_FALSE;
 }
 
 already_AddRefed<nsAccessible>

accessible/src/base/nsAccUtils.h

@@ -283,10 +283,15 @@ public:
   static PRUint8 GetAttributeCharacteristics(nsIAtom* aAtom);
 
   /**
-   * Return the 'live' or 'container-live' object attribute value from the given
+   * Get the 'live' or 'container-live' object attribute value from the given
    * ELiveAttrRule constant.
+   *
+   * @param  aRule   [in] rule constant (see ELiveAttrRule in nsAccMap.h)
+   * @param  aValue  [out] object attribute value
+   *
+   * @return         true if object attribute should be exposed
    */
-  static void GetLiveAttrValue(PRUint32 aRule, nsAString& aValue);
+  static PRBool GetLiveAttrValue(PRUint32 aRule, nsAString& aValue);
 
   /**
    * Query DestinationType from the given SourceType.

accessible/src/base/nsAccessible.cpp

@@ -1748,8 +1748,8 @@ nsAccessible::GetAttributes(nsIPersistentProperties **aAttributes)
     nsAutoString live;
     nsAccUtils::GetAccAttr(attributes, nsAccessibilityAtoms::live, live);
     if (live.IsEmpty()) {
-      nsAccUtils::GetLiveAttrValue(mRoleMapEntry->liveAttRule, live);
-      nsAccUtils::SetAccAttr(attributes, nsAccessibilityAtoms::live, live);
+      if (nsAccUtils::GetLiveAttrValue(mRoleMapEntry->liveAttRule, live))
+        nsAccUtils::SetAccAttr(attributes, nsAccessibilityAtoms::live, live);
     }
   }
 

accessible/tests/mochitest/attributes.js

@@ -22,7 +22,7 @@ function testAttrs(aAccOrElmOrID, aAttrs, aSkipUnexpectedAttrs)
  * @param aAbsentAttrs          [in] map of attributes that should not be
  *                              present (name/value pairs)
  */
-function testAbsentAttrs(aAccOrElmOrID, aAbsentAttrs, aSkipUnexpectedAttrs)
+function testAbsentAttrs(aAccOrElmOrID, aAbsentAttrs)
 {
   testAttrsInternal(aAccOrElmOrID, {}, true, aAbsentAttrs);
 }
@@ -190,6 +190,7 @@ function testAttrsInternal(aAccOrElmOrID, aAttrs, aSkipUnexpectedAttrs,
 function compareAttrs(aErrorMsg, aAttrs, aExpectedAttrs, aSkipUnexpectedAttrs,
                       aAbsentAttrs)
 {
+  // Check if all obtained attributes are expected and have expected value.
   var enumerate = aAttrs.enumerate();
   while (enumerate.hasMoreElements()) {
     var prop = enumerate.getNext().QueryInterface(nsIPropertyElement);
@@ -209,6 +210,7 @@ function compareAttrs(aErrorMsg, aAttrs, aExpectedAttrs, aSkipUnexpectedAttrs,
     }
   }
 
+  // Check if all expected attributes are presented.
   for (var name in aExpectedAttrs) {
     var value = "";
     try {
@@ -220,18 +222,20 @@ function compareAttrs(aErrorMsg, aAttrs, aExpectedAttrs, aSkipUnexpectedAttrs,
          "There is no expected attribute '" + name + "' " + aErrorMsg);
   }
 
-  if (aAbsentAttrs)
+  // Check if all unexpected attributes are absent.
+  if (aAbsentAttrs) {
     for (var name in aAbsentAttrs) {
-      var value = "";
-      try {
-        value = aAttrs.getStringProperty(name);
-      } catch(e) { }
+      var wasFound = false;
 
-      if (value)
-        ok(false,
-           "There is an unexpected attribute '" + name + "' " + aErrorMsg);
-      else
-        ok(true,
-           "There is no unexpected attribute '" + name + "' " + aErrorMsg);
+      var enumerate = aAttrs.enumerate();
+      while (enumerate.hasMoreElements()) {
+        var prop = enumerate.getNext().QueryInterface(nsIPropertyElement);
+        if (prop.key == name)
+          wasFound = true;
+      }
     }
+
+    ok(!wasFound,
+       "There is an unexpected attribute '" + name + "' " + aErrorMsg);
+  }
 }

accessible/tests/mochitest/test_objectattrs.html

@@ -40,6 +40,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=391829
       // live object attribute
       testAttrs("live", {"live" : "polite"}, true);
       testAttrs("live2", {"live" : "polite"}, true);
+      testAbsentAttrs("live3", {"live" : ""});
       testAttrs("log", {"live" : "polite"}, true);
       testAttrs("logAssertive", {"live" : "assertive"}, true);
       testAttrs("marquee", {"live" : "off"}, true);
@@ -121,6 +122,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=391829
 
   <div id="live" aria-live="polite">excuse <div id="liveChild">me</div></div>
   <div id="live2" role="marquee" aria-live="polite">excuse <div id="live2Child">me</div></div>
+  <div id="live3" role="section">excuse</div>
   <div id="log" role="log">excuse <div id="logChild">me</div></div>
   <div id="logAssertive" role="log" aria-live="assertive">excuse <div id="logAssertiveChild">me</div></div>
   <div id="marquee" role="marquee">excuse <div id="marqueeChild">me</div></div>