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authorRich Felker <dalias@aerifal.cx>2015-06-13 05:17:16 +0000
committerRich Felker <dalias@aerifal.cx>2015-06-13 05:17:16 +0000
commit536c6d5a4205e2a3f161f2983ce1e0ac3082187d (patch)
treea45cf47d93d62585cd417b83bd49100edf419222 /src/stdio/ungetwc.c
parentf8f565df467c13248104223f99abf7f37cef7584 (diff)
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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/ungetwc.c')
-rw-r--r--src/stdio/ungetwc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/src/stdio/ungetwc.c b/src/stdio/ungetwc.c
index 394f92ac..d4c7de39 100644
--- a/src/stdio/ungetwc.c
+++ b/src/stdio/ungetwc.c
@@ -11,7 +11,7 @@ wint_t ungetwc(wint_t c, FILE *f)
 
 	FLOCK(f);
 
-	f->mode |= f->mode+1;
+	if (f->mode <= 0) fwide(f, 1);
 
 	if (!f->rpos) __toread(f);
 	if (!f->rpos || f->rpos < f->buf - UNGET + l || c == WEOF ||