commit 2427abe0bde234987ed005a3adca461e9a85dfb7
author James Zern <jzern@google.com> Fri Mar 08 09:39:33 2019
committer James Zern <jzern@google.com> Fri Mar 08 17:28:41 2019
tree a95ff9c33ac539b1cf43b9629a03fce5616d9610
parent 20ac8096f902549cf0b47b5cb539cfff7235cf96

webm_info: avoid null deref w/track->GetCodecId()

check pointer value before converting to string

BUG=webm:1605

Change-Id: I81c1d90517e12c90fc1e3c3c753e273360c9de38

webm_info.cc

diff --git a/webm_info.cc b/webm_info.cc
index cf70d7b..88aee17 100644
--- a/webm_info.cc
+++ b/webm_info.cc
@@ -177,6 +177,8 @@
   return wstr;
 }
 
+string ToString(const char* str) { return string((str == NULL) ? "" : str); }
+
 void OutputEBMLHeader(const mkvparser::EBMLHeader& ebml, FILE* o,
                       Indent* indent) {
   fprintf(o, "EBML Header:\n");
@@ -376,7 +378,7 @@
               static_cast<int>(private_size));
 
       if (track_type == mkvparser::Track::kVideo) {
-        const std::string codec_id = track->GetCodecId();
+        const std::string codec_id = ToString(track->GetCodecId());
         const std::string v_vp9 = "V_VP9";
         if (codec_id == v_vp9) {
           libwebm::Vp9CodecFeatures features;
@@ -1018,7 +1020,7 @@
                 data += frame_offset;
                 frame_size -= frame_offset;
 
-                const string codec_id = track->GetCodecId();
+                const string codec_id = ToString(track->GetCodecId());
                 if (codec_id == "V_VP8") {
                   PrintVP8Info(data, frame_size, o);
                 } else if (codec_id == "V_VP9") {