path: root/src/stdio/vfwscanf.c
diff options
authorRich Felker <>2015-06-13 05:17:16 +0000
committerRich Felker <>2015-06-13 05:17:16 +0000
commit536c6d5a4205e2a3f161f2983ce1e0ac3082187d (patch)
treea45cf47d93d62585cd417b83bd49100edf419222 /src/stdio/vfwscanf.c
parentf8f565df467c13248104223f99abf7f37cef7584 (diff)
fix idiom for setting stdio stream orientation to wide
the old idiom, f->mode |= f->mode+1, was adapted from the idiom for setting byte orientation, f->mode |= f->mode-1, but the adaptation was incorrect. unless the stream was alreasdy set byte-oriented, this code incremented f->mode each time it was executed, which would eventually lead to overflow. it could be fixed by changing it to f->mode |= 1, but upcoming changes will require slightly more work at the time of wide orientation, so it makes sense to just call fwide. as an optimization in the single-character functions, fwide is only called if the stream is not already wide-oriented.
Diffstat (limited to 'src/stdio/vfwscanf.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/src/stdio/vfwscanf.c b/src/stdio/vfwscanf.c
index ac5c2c24..223aad4f 100644
--- a/src/stdio/vfwscanf.c
+++ b/src/stdio/vfwscanf.c
@@ -104,7 +104,7 @@ int vfwscanf(FILE *restrict f, const wchar_t *restrict fmt, va_list ap)
- f->mode |= f->mode+1;
+ fwide(f, 1);
for (p=fmt; *p; p++) {