From b763f84cf1a651f31b239356541de4c77c4c8ec3 Mon Sep 17 00:00:00 2001
From: Jean-Yves Avenard <jyavenard@mozilla.com>
Date: Sat, 9 Jun 2018 13:22:39 +0200
Subject: [PATCH] Bug 1409664 - P15. Fix canPlayType so that it checks codecs
 if provided. r=bryce

Summary:
For flac, mp3 and adts, if a codec was provided but wasn't supported in the container, it would have reported Maybe instead of No

Depends on D1628

Tags: #secure-revision

Bug #: 1409664

Differential Revision: https://phabricator.services.mozilla.com/D1629
---
 dom/media/DecoderTraits.cpp | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/dom/media/DecoderTraits.cpp b/dom/media/DecoderTraits.cpp
index 532dc891b175..e4b8d53440b4 100644
--- a/dom/media/DecoderTraits.cpp
+++ b/dom/media/DecoderTraits.cpp
@@ -121,14 +121,29 @@ CanHandleCodecsType(const MediaContainerType& aType,
     return CANPLAY_NO;
   }
 #endif
-  if (MP3Decoder::IsSupportedType(aType)) {
-    return CANPLAY_YES;
+  if (MP3Decoder::IsSupportedType(mimeType)) {
+    if (MP3Decoder::IsSupportedType(aType)) {
+      return CANPLAY_YES;
+    }
+    // We can only reach this position if a particular codec was requested,
+    // mp3 is supported and working: the codec must be invalid.
+    return CANPLAY_NO;
   }
-  if (ADTSDecoder::IsSupportedType(aType)) {
-    return CANPLAY_YES;
+  if (ADTSDecoder::IsSupportedType(mimeType)) {
+    if (ADTSDecoder::IsSupportedType(aType)) {
+      return CANPLAY_YES;
+    }
+    // We can only reach this position if a particular codec was requested,
+    // adts is supported and working: the codec must be invalid.
+    return CANPLAY_NO;
   }
-  if (FlacDecoder::IsSupportedType(aType)) {
-    return CANPLAY_YES;
+  if (FlacDecoder::IsSupportedType(mimeType)) {
+    if (FlacDecoder::IsSupportedType(aType)) {
+      return CANPLAY_YES;
+    }
+    // We can only reach this position if a particular codec was requested,
+    // flac is supported and working: the codec must be invalid.
+    return CANPLAY_NO;
   }
 
   return CANPLAY_MAYBE;