X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Finternal%2Fshgetc.c;h=7455d2f00a04e477db9f4129fb4d5ba0809af1cb;hb=fa4a8abd06a401822cc8ba4e352a219544c0118d;hp=82e3a4fa69152097e5c231edf8d4d8d1c82786f6;hpb=cc00f05632e5d7cbfb8ce49f4b0dfd59c3cf611d;p=musl

diff --git a/src/internal/shgetc.c b/src/internal/shgetc.c
index 82e3a4fa..7455d2f0 100644
--- a/src/internal/shgetc.c
+++ b/src/internal/shgetc.c
@@ -1,9 +1,15 @@
 #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;
+	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
@@ -13,12 +19,19 @@ void __shlim(FILE *f, off_t lim)
 int __shgetc(FILE *f)
 {
 	int c;
-	if (f->shcnt >= f->shlim) return EOF;
-	c = __uflow(f);
-	if (f->shlim && f->rend - f->rpos > f->shlim - f->shcnt - 1)
-		f->shend = f->rpos + (f->shlim - f->shcnt - 1);
+	off_t cnt = shcnt(f);
+	if (f->shlim && cnt >= f->shlim || (c=__uflow(f)) < 0) {
+		f->shcnt = f->buf - f->rpos + cnt;
+		f->shend = f->rpos;
+		f->shlim = -1;
+		return EOF;
+	}
+	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->buf;
+	f->shcnt = f->buf - f->rpos + cnt;
+	if (f->rpos <= f->buf) f->rpos[-1] = c;
 	return c;
 }