Bug 1329480: [MSE] Do not reject partial boxes. r=gerald

Partial content less than 8 bytes long was incorrectly rejected.

We now assume that content is valid unless it is explicitly incorrect (bad box type)

MozReview-Commit-ID: 8L32mNVjzxh

--HG--
extra : rebase_source : 980242aab96d5b96dc7e62ad289e8ecd7b228032

dom/media/mediasource/ContainerParser.cpp

@@ -20,6 +20,7 @@
 #endif
 #include "nsAutoPtr.h"
 #include "SourceBufferResource.h"
+#include <algorithm>
 
 extern mozilla::LogModule* GetMediaSourceSamplesLog();
 
@@ -348,6 +349,9 @@ public:
     // Each MP4 atom has a chunk size and chunk type. The root chunk in an MP4
     // file is the 'ftyp' atom followed by a file type. We just check for a
     // vaguely valid 'ftyp' atom.
+    if (aData->Length() < 8) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
     AtomParser parser(mType, aData);
     if (!parser.IsValid()) {
       return MediaResult(
@@ -359,6 +363,9 @@ public:
 
   MediaResult IsMediaSegmentPresent(MediaByteBuffer* aData) override
   {
+    if (aData->Length() < 8) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
     AtomParser parser(mType, aData);
     if (!parser.IsValid()) {
       return MediaResult(
@@ -396,20 +403,15 @@ private:
         MSE_DEBUGV(AtomParser ,"Checking atom:'%c%c%c%c' @ %u",
                    typec[0], typec[1], typec[2], typec[3],
                    (uint32_t)reader.Offset() - 8);
-
-        for (const auto& boxType : validBoxes) {
-          if (type == boxType) {
-            mValid = true;
-            break;
-          }
-        }
-        if (!mValid) {
-          // No point continuing.
+        if (std::find(std::begin(validBoxes), std::end(validBoxes), type)
+            == std::end(validBoxes)) {
+          // No valid box found, no point continuing.
           mLastInvalidBox[0] = typec[0];
           mLastInvalidBox[1] = typec[1];
           mLastInvalidBox[2] = typec[2];
           mLastInvalidBox[3] = typec[3];
           mLastInvalidBox[4] = '\0';
+          mValid = false;
           break;
         }
         if (mInitOffset.isNothing() &&
@@ -458,7 +460,7 @@ private:
   private:
     Maybe<size_t> mInitOffset;
     Maybe<size_t> mMediaOffset;
-    bool mValid = false;
+    bool mValid = true;
     char mLastInvalidBox[5];
   };