diff options
authorRich Felker <>2018-08-28 19:22:13 -0400
committerRich Felker <>2018-08-28 20:01:25 -0400
commitb152d575fdde1b4173afb4cade55f35b6b2e9128 (patch)
parentf66022dda8d18e6732626c7806f6c4d32023d574 (diff)
set stream orientations in open_[w]memstream
fundamentally there is no good reason these functions need to set an orientation (morally it should be possible to write a wchar_t[] memory stream using byte functions, or a char[] memory stream using wide functions), but it's a part of the specification that they do. aside from being able to inspect the orientation with fwide, failure to set the orientation in open_wmemstream is observable if the locale changes between open_wmemstream and the first operation on the stream; this is because the encoding rule (locale) for the stream is required to be bound at the time the stream becomes wide-oriented. for open_wmemstream, call fwide to avoid duplicating the logic for binding the encoding rule. for open_memstream it suffices just to set the mode field in the FILE struct.
2 files changed, 3 insertions, 0 deletions
diff --git a/src/stdio/open_memstream.c b/src/stdio/open_memstream.c
index ee834234..40f5ad60 100644
--- a/src/stdio/open_memstream.c
+++ b/src/stdio/open_memstream.c
@@ -89,6 +89,7 @@ FILE *open_memstream(char **bufp, size_t *sizep)
f->f.write = ms_write;
f-> = ms_seek;
f->f.close = ms_close;
+ f->f.mode = -1;
if (!libc.threaded) f->f.lock = -1;
diff --git a/src/stdio/open_wmemstream.c b/src/stdio/open_wmemstream.c
index cb693ea7..a7c3a645 100644
--- a/src/stdio/open_wmemstream.c
+++ b/src/stdio/open_wmemstream.c
@@ -94,5 +94,7 @@ FILE *open_wmemstream(wchar_t **bufp, size_t *sizep)
if (!libc.threaded) f->f.lock = -1;
+ fwide(&f->f, 1);
return __ofl_add(&f->f);