From 2e00d0c536c64a4dc1d552f1004b8c057e85aad2 Mon Sep 17 00:00:00 2001
From: casey langen <casey.langen@gmail.com>
Date: Sun, 12 Aug 2018 22:37:14 -0700
Subject: [PATCH] OK, now that there are clear repro steps, the crash on
 invalid metadata should be fixed for reals.

---
 src/core/audio/PlaybackService.cpp     | 30 +++++++++++++++-----------
 src/plugins/server/Util.h              |  8 +++----
 src/plugins/server/WebSocketServer.cpp | 24 +++++++++++++++------
 3 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/src/core/audio/PlaybackService.cpp b/src/core/audio/PlaybackService.cpp
index edc9f3e20..03133dc8f 100755
--- a/src/core/audio/PlaybackService.cpp
+++ b/src/core/audio/PlaybackService.cpp
@@ -809,7 +809,10 @@ ITrack* PlaybackService::GetTrack(size_t index) {
     const size_t count = this->playlist.Count();
 
     if (count && index < this->playlist.Count()) {
-        return this->playlist.Get(index)->GetSdkValue();
+        auto track = this->playlist.Get(index);
+        if (track) {
+            return track->GetSdkValue();
+        }
     }
 
     return nullptr;
@@ -1093,17 +1096,20 @@ ITransport::Gain PlaybackService::GainAtIndex(size_t index) {
     Mode mode = (Mode)playbackPrefs->GetInt(keys::ReplayGainMode.c_str(), (int) Mode::Disabled);
 
     if (mode != Mode::Disabled && index < this->playlist.Count()) {
-        int64_t id = this->playlist.Get(index)->GetId();
-        auto query = std::make_shared<ReplayGainQuery>(id);
-        if (this->library->Enqueue(query, ILibrary::QuerySynchronous)) {
-            auto rg = query->GetResult();
-            float gain = (mode == Mode::Album) ? rg->albumGain : rg->trackGain;
-            float peak = (mode == Mode::Album) ? rg->albumPeak : rg->trackPeak;
-            if (gain != 1.0f) {
-                /* http://wiki.hydrogenaud.io/index.php?title=ReplayGain_2.0_specification#Reduced_gain */
-                result.gain = powf(10.0f, (gain / 20.0f));
-                result.peak = (1.0f / peak);
-                result.peakValid = true;
+        auto track = this->playlist.Get(index);
+        if (track) {
+            int64_t id = track->GetId();
+            auto query = std::make_shared<ReplayGainQuery>(id);
+            if (this->library->Enqueue(query, ILibrary::QuerySynchronous)) {
+                auto rg = query->GetResult();
+                float gain = (mode == Mode::Album) ? rg->albumGain : rg->trackGain;
+                float peak = (mode == Mode::Album) ? rg->albumPeak : rg->trackPeak;
+                if (gain != 1.0f) {
+                    /* http://wiki.hydrogenaud.io/index.php?title=ReplayGain_2.0_specification#Reduced_gain */
+                    result.gain = powf(10.0f, (gain / 20.0f));
+                    result.peak = (1.0f / peak);
+                    result.peakValid = true;
+                }
             }
         }
     }
diff --git a/src/plugins/server/Util.h b/src/plugins/server/Util.h
index 8787d755a..eaf434ee8 100644
--- a/src/plugins/server/Util.h
+++ b/src/plugins/server/Util.h
@@ -68,11 +68,11 @@ static std::string GetPreferenceString(
 
 template <typename MetadataT>
 static std::string GetMetadataString(
-    MetadataT* metadata, 
-    const std::string& key, 
+    MetadataT* metadata,
+    const std::string& key,
     const std::string& defaultValue = "missing metadata!")
 {
-    if (!metadata) { defaultValue; }
+    if (!metadata) { return defaultValue; }
     metadata->GetString(key.c_str(), threadLocalBuffer, sizeof(threadLocalBuffer));
     return std::string(threadLocalBuffer);
 }
@@ -89,7 +89,7 @@ static int64_t GetMetadataInt64(MetadataT* metadata, const std::string& key, int
 
 static std::string GetValueString(
     musik::core::sdk::IValue* value,
-    const std::string& defaultValue = "missing metadata!") 
+    const std::string& defaultValue = "missing metadata!")
 {
     if (!value) { return defaultValue; }
     value->GetValue(threadLocalBuffer, sizeof(threadLocalBuffer));
diff --git a/src/plugins/server/WebSocketServer.cpp b/src/plugins/server/WebSocketServer.cpp
index b67552bca..75bb8b2cd 100644
--- a/src/plugins/server/WebSocketServer.cpp
+++ b/src/plugins/server/WebSocketServer.cpp
@@ -785,9 +785,15 @@ void WebSocketServer::RespondWithPlayQueueTracks(connection_hdl connection, json
 
             for (int i = offset; i < to; i++) {
                 ITrack* track = context.playback->GetTrack(i);
-                if (idsOnly) { data.push_back(GetMetadataString(track, key::external_id)); }
-                else { data.push_back(this->ReadTrackMetadata(track)); }
-                track->Release();
+                if (idsOnly) {
+                    data.push_back(GetMetadataString(track, key::external_id));
+                }
+                else {
+                    data.push_back(this->ReadTrackMetadata(track));
+                }
+                if (track) {
+                    track->Release();
+                }
             }
 
             editor->Release();
@@ -803,9 +809,15 @@ void WebSocketServer::RespondWithPlayQueueTracks(connection_hdl connection, json
 
                 for (int i = offset; i < to; i++) {
                     ITrack* track = snapshot->GetTrack(i);
-                    if (idsOnly) { data.push_back(GetMetadataString(track, key::external_id)); }
-                    else { data.push_back(this->ReadTrackMetadata(track)); }
-                    track->Release();
+                    if (idsOnly) {
+                        data.push_back(GetMetadataString(track, key::external_id));
+                    }
+                    else {
+                        data.push_back(this->ReadTrackMetadata(track));
+                    }
+                    if (track) {
+                        track->Release();
+                    }
                 }
             }
         }