[libcxx-commits] [PATCH] D150044: [libc++][print] Adds FILE functions.

[Mikael Holmén via Phabricator via libcxx-commits]

uabelho added inline comments.


================
Comment at: libcxx/test/libcxx/input.output/iostream.format/print.fun/vprint_unicode_posix.pass.cpp:40
+
+  FILE* file = fmemopen(buffer.data(), buffer.size(), "wb");
+  assert(file);
----------------
When I run this testcase the assert on line 48 below fails for me, and it seems to be because the "fmemopen" call here writes '\0' at the first byte in buffer.

I really doen't know anything about this and if I read at 
 https://man7.org/linux/man-pages/man3/fmemopen.3.html
it says
```
       w      The stream is opened for writing.
```
and also
```
       w+     Open the stream for reading and writing.  The buffer
              contents are truncated (i.e., '\0' is placed in the first
              byte of the buffer).
```
So it seems like when I run this in my environment "w" partly does what "w+" should do.

Does this problem sound familiar to anyone?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D150044/new/

https://reviews.llvm.org/D150044