input_buffer_adapter: Fix handling of nullptr input

Clang UBSAN currently complains that the char * to input_buffer_adapter
is a nullptr.

Turns out it is actually required to accept nullptr, see for example
line 415 in input_adapters.hpp

  ...
  // the address of first cannot be used: use nullptr
  ia = std::make_shared<input_buffer_adapter>(nullptr, len);
  ....

Therefore we have to handle it gracefully here. We now also ignore the
length parameter l if b is a nullptr.
This commit is contained in:
Thomas Braun 2019-08-30 12:39:46 +02:00
parent 9ea3e19121
commit 61fe5f1eee
2 changed files with 4 additions and 4 deletions

View file

@ -131,9 +131,8 @@ class input_stream_adapter : public input_adapter_protocol
class input_buffer_adapter : public input_adapter_protocol class input_buffer_adapter : public input_adapter_protocol
{ {
public: public:
JSON_HEDLEY_NON_NULL(2)
input_buffer_adapter(const char* b, const std::size_t l) noexcept input_buffer_adapter(const char* b, const std::size_t l) noexcept
: cursor(b), limit(b + l) : cursor(b), limit(b == nullptr ? nullptr : (b + l))
{} {}
// delete because of pointer members // delete because of pointer members
@ -147,6 +146,7 @@ class input_buffer_adapter : public input_adapter_protocol
{ {
if (JSON_HEDLEY_LIKELY(cursor < limit)) if (JSON_HEDLEY_LIKELY(cursor < limit))
{ {
assert(cursor != nullptr and limit != nullptr);
return std::char_traits<char>::to_int_type(*(cursor++)); return std::char_traits<char>::to_int_type(*(cursor++));
} }

View file

@ -3882,9 +3882,8 @@ class input_stream_adapter : public input_adapter_protocol
class input_buffer_adapter : public input_adapter_protocol class input_buffer_adapter : public input_adapter_protocol
{ {
public: public:
JSON_HEDLEY_NON_NULL(2)
input_buffer_adapter(const char* b, const std::size_t l) noexcept input_buffer_adapter(const char* b, const std::size_t l) noexcept
: cursor(b), limit(b + l) : cursor(b), limit(b == nullptr ? nullptr : (b + l))
{} {}
// delete because of pointer members // delete because of pointer members
@ -3898,6 +3897,7 @@ class input_buffer_adapter : public input_adapter_protocol
{ {
if (JSON_HEDLEY_LIKELY(cursor < limit)) if (JSON_HEDLEY_LIKELY(cursor < limit))
{ {
assert(cursor != nullptr and limit != nullptr);
return std::char_traits<char>::to_int_type(*(cursor++)); return std::char_traits<char>::to_int_type(*(cursor++));
} }