From eea8a1b07abc4c50d832525e7cee46099d725864 Mon Sep 17 00:00:00 2001
From: Jacob Dufault <jacobdufault@gmail.com>
Date: Sat, 18 Nov 2017 09:27:37 -0800
Subject: [PATCH] Try to avoid crashing when deserializing JSON

---
 src/indexer.h              |  3 ++-
 src/language_server_api.cc |  4 ++++
 src/position.cc            | 10 ++++++++--
 src/serializer.cc          | 18 ++++++++++++------
 src/serializer.h           |  4 ++++
 5 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/src/indexer.h b/src/indexer.h
index aad78f8e..ed20c819 100644
--- a/src/indexer.h
+++ b/src/indexer.h
@@ -64,7 +64,8 @@ bool operator!=(const Id<T>& a, const Id<T>& b) {
 
 template <typename T>
 void Reflect(Reader& visitor, Id<T>& id) {
-  id.id = visitor.GetUint64();
+  if (visitor.IsUint64())
+    id.id = visitor.GetUint64();
 }
 template <typename T>
 void Reflect(Writer& visitor, Id<T>& value) {
diff --git a/src/language_server_api.cc b/src/language_server_api.cc
index 9c1471c8..71d5bc3c 100644
--- a/src/language_server_api.cc
+++ b/src/language_server_api.cc
@@ -303,6 +303,10 @@ const std::string& lsCompletionItem::InsertedContent() const {
 }
 
 void Reflect(Reader& reader, lsInitializeParams::lsTrace& value) {
+  if (!reader.IsString()) {
+    value = lsInitializeParams::lsTrace::Off;
+    return;
+  }
   std::string v = reader.GetString();
   if (v == "off")
     value = lsInitializeParams::lsTrace::Off;
diff --git a/src/position.cc b/src/position.cc
index 32c9e87f..07b90a06 100644
--- a/src/position.cc
+++ b/src/position.cc
@@ -146,7 +146,10 @@ bool Range::operator<(const Range& that) const {
 
 // Position
 void Reflect(Reader& visitor, Position& value) {
-  value = Position(visitor.GetString());
+  if (!visitor.IsString())
+    value = Position();
+  else
+    value = Position(visitor.GetString());
 }
 void Reflect(Writer& visitor, Position& value) {
   std::string output = value.ToString();
@@ -155,7 +158,10 @@ void Reflect(Writer& visitor, Position& value) {
 
 // Range
 void Reflect(Reader& visitor, Range& value) {
-  value = Range(visitor.GetString());
+  if (!visitor.IsString())
+    value = Range();
+  else
+    value = Range(visitor.GetString());
 }
 void Reflect(Writer& visitor, Range& value) {
   std::string output = value.ToString();
diff --git a/src/serializer.cc b/src/serializer.cc
index b573cbcf..3a437831 100644
--- a/src/serializer.cc
+++ b/src/serializer.cc
@@ -8,42 +8,48 @@ bool gTestOutputMode = false;
 
 // int16_t
 void Reflect(Reader& visitor, int16_t& value) {
-  value = (int16_t)visitor.GetInt();
+  if (visitor.IsInt())
+    value = (int16_t)visitor.GetInt();
 }
 void Reflect(Writer& visitor, int16_t& value) {
   visitor.Int(value);
 }
 // int32_t
 void Reflect(Reader& visitor, int32_t& value) {
-  value = visitor.GetInt();
+  if (visitor.IsInt())
+    value = visitor.GetInt();
 }
 void Reflect(Writer& visitor, int32_t& value) {
   visitor.Int(value);
 }
 // int64_t
 void Reflect(Reader& visitor, int64_t& value) {
-  value = visitor.GetInt64();
+  if (visitor.IsInt64())
+    value = visitor.GetInt64();
 }
 void Reflect(Writer& visitor, int64_t& value) {
   visitor.Int64(value);
 }
 // uint64_t
 void Reflect(Reader& visitor, uint64_t& value) {
-  value = visitor.GetUint64();
+  if (visitor.IsUint64())
+    value = visitor.GetUint64();
 }
 void Reflect(Writer& visitor, uint64_t& value) {
   visitor.Uint64(value);
 }
 // bool
 void Reflect(Reader& visitor, bool& value) {
-  value = visitor.GetBool();
+  if (visitor.IsBool())
+    value = visitor.GetBool();
 }
 void Reflect(Writer& visitor, bool& value) {
   visitor.Bool(value);
 }
 // std::string
 void Reflect(Reader& visitor, std::string& value) {
-  value = visitor.GetString();
+  if (visitor.IsString())
+    value = visitor.GetString();
 }
 void Reflect(Writer& visitor, std::string& value) {
   visitor.String(value.c_str(), (rapidjson::SizeType)value.size());
diff --git a/src/serializer.h b/src/serializer.h
index cd2699de..083a0d73 100644
--- a/src/serializer.h
+++ b/src/serializer.h
@@ -168,6 +168,8 @@ void ReflectMember(Writer& visitor, const char* name, std::string& value);
 // Reader:
 template <typename T>
 void Reflect(Reader& visitor, std::vector<T>& values) {
+  if (!visitor.IsArray())
+    return;
   for (auto& entry : visitor.GetArray()) {
     T entry_value;
     Reflect(entry, entry_value);
@@ -176,6 +178,8 @@ void Reflect(Reader& visitor, std::vector<T>& values) {
 }
 template <typename T>
 void Reflect(Reader& visitor, optional<T>& value) {
+  if (visitor.IsNull())
+    return;
   T real_value;
   Reflect(visitor, real_value);
   value = real_value;