diff options
| -rw-r--r-- | libc/stdio/stdio.c | 50 |
1 files changed, 33 insertions, 17 deletions
diff --git a/libc/stdio/stdio.c b/libc/stdio/stdio.c index cf6450995..b4208f97c 100644 --- a/libc/stdio/stdio.c +++ b/libc/stdio/stdio.c @@ -25,6 +25,19 @@ * * ATTENTION! ATTENTION! ATTENTION! ATTENTION! ATTENTION! */ +/* 8-05-2002 + * Changed fflush() behavior to no-op for r/w streams in read-mode. + * This falls under undefined behavior wrt ANSI/ISO C99, but + * SUSv3 seems to treat it as a no-op and it occurs in some apps. + * Fixed a problem with _stdio_fwrite() not checking for underlying + * write() failures. + * Fixed both _stdio_fwrite() and _stdio_fread() to make sure that + * the putc and getc macros were disabled if the stream was in + * and error state. + * The above changes should take care of a problem initially reported + * by "Steven J. Hill" <sjhill@realitydiluted.com>. + */ + /* Before we include anything, convert L_ctermid to L_ctermid_function * and undef L_ctermid if defined. This is necessary as L_ctermid is * a SUSv3 standard macro defined in stdio.h. */ @@ -1385,7 +1398,9 @@ size_t _stdio_fread(unsigned char *buffer, size_t bytes, register FILE *stream) } #ifdef __STDIO_GETC_MACRO - if (!(stream->modeflags & (__FLAG_WIDE|__MASK_UNGOT|__MASK_BUFMODE))) { + if (!(stream->modeflags + & (__FLAG_WIDE|__MASK_UNGOT|__MASK_BUFMODE|__FLAG_ERROR)) + ) { stream->bufgetc = stream->bufread; /* Enable getc macro. */ } #endif @@ -1565,6 +1580,7 @@ size_t _stdio_fwrite(const unsigned char *buffer, size_t bytes, { const unsigned char *buf0 = buffer; + size_t write_count = 1; /* 0 means a write failed */ if (!buffer) { /* fflush the stream */ FFLUSH: @@ -1578,9 +1594,9 @@ size_t _stdio_fwrite(const unsigned char *buffer, size_t bytes, } { - size_t rv = _stdio_WRITE(stream, p, count); - p += rv; - count -= rv; + write_count = _stdio_WRITE(stream, p, count); + p += write_count; + count -= write_count; } stream->bufpos = stream->bufstart; @@ -1624,21 +1640,23 @@ size_t _stdio_fwrite(const unsigned char *buffer, size_t bytes, --count; } - if (bytes) { - goto FFLUSH; - } + if (write_count) { /* no write errors */ + if (bytes) { + goto FFLUSH; + } - if (stream->modeflags & __FLAG_LBF) { - while (p < buffer) { /* check for newline. */ - if (*p++ == '\n') { - goto FFLUSH; + if (stream->modeflags & __FLAG_LBF) { + while (p < buffer) { /* check for newline. */ + if (*p++ == '\n') { + goto FFLUSH; + } } } } } #ifdef __STDIO_PUTC_MACRO - if (!(stream->modeflags & (__FLAG_WIDE|__MASK_BUFMODE))) { + if (!(stream->modeflags & (__FLAG_WIDE|__MASK_BUFMODE|__FLAG_ERROR))) { /* Not wide, no errors and fully buffered, so enable putc macro. */ stream->bufputc = stream->bufend; } @@ -2127,13 +2145,11 @@ int fflush_unlocked(register FILE *stream) if (_stdio_fwrite(NULL, 0, stream) > 0) { /* flush buffer contents. */ rv = -1; /* Not all chars written. */ } - } else if (stream->modeflags & (__FLAG_READONLY|__FLAG_READING)) { - /* TODO - __FLAG_READING too? check glibc behavior */ + } else if (stream->modeflags & __FLAG_READONLY) { /* According to info, glibc returns an error when the file is opened * in read-only mode. * ANSI/ISO says behavior in this case is undefined but also says you - * shouldn't flush a stream you were reading from. - */ + * shouldn't flush a stream you were reading from. */ stream->modeflags |= __FLAG_ERROR; /* TODO - check glibc behavior */ __set_errno(EBADF); rv = -1; @@ -2156,7 +2172,7 @@ int fflush_unlocked(register FILE *stream) /* TODO -- check glibc behavior regarding error indicator */ return ((stream != NULL) - && (stream->modeflags & (__FLAG_READONLY|__FLAG_READING)) + && (stream->modeflags & __FLAG_READONLY) ? ((stream->modeflags |= __FLAG_ERROR), __set_errno(EBADF), EOF) : 0 ); |