Bug 1162299 - Distinguish between all features and unrecognized feature. r=kats

--HG--
extra : rebase_source : 964896852d223f4b4e69b53acf1084d11b96a247

widget/GfxInfoBase.cpp

@@ -311,6 +311,7 @@ BlacklistDevicesToDeviceFamily(nsIDOMHTMLCollection* aDevices)
 static int32_t
 BlacklistFeatureToGfxFeature(const nsAString& aFeature)
 {
+  MOZ_ASSERT(!aFeature.IsEmpty());
   if (aFeature.EqualsLiteral("DIRECT2D"))
     return nsIGfxInfo::FEATURE_DIRECT2D;
   else if (aFeature.EqualsLiteral("DIRECT3D_9_LAYERS"))
@@ -337,7 +338,13 @@ BlacklistFeatureToGfxFeature(const nsAString& aFeature)
     return nsIGfxInfo::FEATURE_STAGEFRIGHT;
   else if (aFeature.EqualsLiteral("WEBRTC_HW_ACCELERATION"))
     return nsIGfxInfo::FEATURE_WEBRTC_HW_ACCELERATION;
-  return 0;
+
+  // If we don't recognize the feature, it may be new, and something
+  // this version doesn't understand.  So, nothing to do.  This is
+  // different from feature not being specified at all, in which case
+  // this method should not get called and we should continue with the
+  // "all features" blocklisting.
+  return -1;
 }
 
 static int32_t
@@ -525,6 +532,11 @@ BlacklistEntryToDriverInfo(nsIDOMNode* aBlacklistEntry,
                                   getter_AddRefs(dataNode))) {
     BlacklistNodeToTextValue(dataNode, dataValue);
     aDriverInfo.mFeature = BlacklistFeatureToGfxFeature(dataValue);
+    if (aDriverInfo.mFeature < 0) {
+      // If we don't recognize the feature, we do not want to proceed.
+      gfxWarning() << "Unrecognized feature " << NS_ConvertUTF16toUTF8(dataValue).get();
+      return false;
+    }
   }
 
   // <featureStatus> BLOCKED_DRIVER_VERSION </featureStatus>

widget/nsIGfxInfo.idl

@@ -64,7 +64,7 @@ interface nsIGfxInfo : nsISupports
    * A set of constants for features that we can ask this GfxInfo object
    * about via GetFeatureStatus
    */
-  /* Don't assign 0 or -1 */
+  /* Don't assign any value <= 0 */
   /* Whether Direct2D is supported for content rendering. */
   const long FEATURE_DIRECT2D = 1;
   /* Whether Direct3D 9 is supported for layers. */
@@ -81,15 +81,15 @@ interface nsIGfxInfo : nsISupports
   const long FEATURE_WEBGL_ANGLE = 7;
   /* Whether WebGL antialiasing is supported. */
   const long FEATURE_WEBGL_MSAA = 8;
-  /* Whether Stagefright is supported */
+  /* Whether Stagefright is supported, starting in 17. */
   const long FEATURE_STAGEFRIGHT = 9;
-  /* Whether Webrtc Hardware acceleration is supported */
+  /* Whether Webrtc Hardware acceleration is supported, starting in 31. */
   const long FEATURE_WEBRTC_HW_ACCELERATION = 10;
-  /* Whether Direct3D 11 is supported for layers. */
+  /* Whether Direct3D 11 is supported for layers, starting in 32. */
   const long FEATURE_DIRECT3D_11_LAYERS = 11;
-  /* Whether hardware accelerated video decoding is supported. */
+  /* Whether hardware accelerated video decoding is supported, starting in 36. */
   const long FEATURE_HARDWARE_VIDEO_DECODING = 12;
-  /* Whether Direct3D 11 is supported for ANGLE. */
+  /* Whether Direct3D 11 is supported for ANGLE, starting in 38. */
   const long FEATURE_DIRECT3D_11_ANGLE = 13;
 
   /*