path: root/src
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authorRich Felker <dalias@aerifal.cx>2022-02-20 20:11:14 -0500
committerRich Felker <dalias@aerifal.cx>2022-02-20 20:21:06 -0500
commitf8bdc3048216f41eaaf655524fa286cfb1184a70 (patch)
tree70ce8e06a28fc69a1e25035e780e125fd8075010 /src
parent5690668a1bb9f551bb78d825bc804dcebe84b7e7 (diff)
fix spurious failures by fgetws when buffer ends with partial character
commit a90d9da1d1b14d81c4f93e1a6d1a686c3312e4ba made fgetws look for changes to errno by fgetwc to detect encoding errors, since ISO C did not allow the implementation to set the stream's error flag in this case, and the fgetwc interface did not admit any other way to detect the error. however, the possibility of fgetwc setting errno to EILSEQ in the success path was overlooked, and in fact this can happen if the buffer ends with a partial character, causing mbtowc to be called with only part of the character available. since that change was made, the C standard was amended to specify that fgetwc set the stream error flag on encoding errors, and commit 511d70738bce11a67219d0132ce725c323d00e4e made it do so. thus, there is no longer any need for fgetws to poke at errno to handle encoding errors. this commit reverts commit a90d9da1d1b14d81c4f93e1a6d1a686c3312e4ba and thereby fixes the problem.
Diffstat (limited to 'src')
1 files changed, 1 insertions, 6 deletions
diff --git a/src/stdio/fgetws.c b/src/stdio/fgetws.c
index b08b3049..195cb435 100644
--- a/src/stdio/fgetws.c
+++ b/src/stdio/fgetws.c
@@ -1,6 +1,5 @@
#include "stdio_impl.h"
#include <wchar.h>
-#include <errno.h>
wint_t __fgetwc_unlocked(FILE *);
@@ -12,10 +11,6 @@ wchar_t *fgetws(wchar_t *restrict s, int n, FILE *restrict f)
- /* Setup a dummy errno so we can detect EILSEQ. This is
- * the only way to catch encoding errors in the form of a
- * partial character just before EOF. */
- errno = EAGAIN;
for (; n; n--) {
wint_t c = __fgetwc_unlocked(f);
if (c == WEOF) break;
@@ -23,7 +18,7 @@ wchar_t *fgetws(wchar_t *restrict s, int n, FILE *restrict f)
if (c == '\n') break;
*p = 0;
- if (ferror(f) || errno==EILSEQ) p = s;
+ if (ferror(f)) p = s;