tree 28be518c9dd7b33b0952346d00a3cc187a5dd93f
parent 2c4b419ec4e386f2ade25a7068233ce7be0f593d
author Thomas Anderson <thomasanderson@google.com> 1553629890 +0000
committer Thomas Anderson <thomasanderson@google.com> 1553629890 +0000

[libc++] Fix return value of snprintf_l() on Windows when buffer is too small

When the output buffer is too small to contain the output, `vsnprintf()`
fills the buffer and returns the number of characters that __would have__
been written if the buffer was sufficiently large.

`_vnsprintf_s()` on the other hand fills the buffer and returns -1 when this
happens.  We want the former behavior, but we also want to be able to
pass in a locale to prevent having to call `setlocale()`.

`__stdio_common_vsprintf()` is the only function general enough to get
the behavior we want.

Differential Revision: https://reviews.llvm.org/D59727


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@357024 91177308-0d34-0410-b5e6-96231b3b80d8