This patch fixes a bug into ostream::operator<<(double) due to the wrong size passed into the __convert_from_v method. The wrong size is then passed to std::snprintf function, that, on uClibc, doens't handle sized 0 buffer. Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com> --- a/libstdc++-v3/include/bits/locale_facets.tcc +++ b/libstdc++-v3/include/bits/locale_facets.tcc @@ -1149,7 +1149,7 @@ _GLIBCXX_BEGIN_LDBL_NAMESPACE const int __cs_size = __fixed ? __max_exp + __prec + 4 : __max_digits * 2 + __prec; char* __cs = static_cast<char*>(__builtin_alloca(__cs_size)); - __len = std::__convert_from_v(_S_get_c_locale(), __cs, 0, __fbuf, + __len = std::__convert_from_v(_S_get_c_locale(), __cs, __cs_size, __fbuf, __prec, __v); #endif @@ -1789,7 +1789,7 @@ _GLIBCXX_BEGIN_LDBL_NAMESPACE // max_exponent10 + 1 for the integer part, + 2 for sign and '\0'. const int __cs_size = numeric_limits<long double>::max_exponent10 + 3; char* __cs = static_cast<char*>(__builtin_alloca(__cs_size)); - int __len = std::__convert_from_v(_S_get_c_locale(), __cs, 0, "%.*Lf", + int __len = std::__convert_from_v(_S_get_c_locale(), __cs, __cs_size, "%.*Lf", 0, __units); #endif string_type __digits(__len, char_type());