diff options
Diffstat (limited to 'src/internal/shgetc.c')
| -rw-r--r-- | src/internal/shgetc.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/internal/shgetc.c b/src/internal/shgetc.c index e878b00a..ebd5fae7 100644 --- a/src/internal/shgetc.c +++ b/src/internal/shgetc.c @@ -1,10 +1,16 @@ #include "shgetc.h" +/* The shcnt field stores the number of bytes read so far, offset by + * the value of buf-rpos at the last function call (__shlim or __shgetc), + * so that between calls the inline shcnt macro can add rpos-buf to get + * the actual count. */ + void __shlim(FILE *f, off_t lim) { f->shlim = lim; - f->shcnt = f->rend - f->rpos; - if (lim && f->shcnt > lim) + f->shcnt = f->buf - f->rpos; + /* If lim is nonzero, rend must be a valid pointer. */ + if (lim && f->rend - f->rpos > lim) f->shend = f->rpos + lim; else f->shend = f->rend; @@ -13,15 +19,18 @@ void __shlim(FILE *f, off_t lim) int __shgetc(FILE *f) { int c; - if (f->shlim && f->shcnt >= f->shlim || (c=__uflow(f)) < 0) { + off_t cnt = shcnt(f); + if (f->shlim && cnt >= f->shlim || (c=__uflow(f)) < 0) { + f->shcnt = f->buf - f->rpos + cnt; f->shend = 0; return EOF; } - if (f->shlim && f->rend - f->rpos > f->shlim - f->shcnt - 1) - f->shend = f->rpos + (f->shlim - f->shcnt - 1); + cnt++; + if (f->shlim && f->rend - f->rpos > f->shlim - cnt) + f->shend = f->rpos + (f->shlim - cnt); else f->shend = f->rend; - if (f->rend) f->shcnt += f->rend - f->rpos + 1; + f->shcnt = f->buf - f->rpos + cnt; if (f->rpos[-1] != c) f->rpos[-1] = c; return c; } |