apparently fseek should not set the error flag on failed seek

src/stdio/fseek.c

@@ -15,10 +15,7 @@ int __fseeko_unlocked(FILE *f, off_t off, int whence)
 	f->wpos = f->wbase = f->wend = 0;
 
 	/* Perform the underlying seek. */
-	if (f->seek(f, off, whence) < 0) {
-		f->flags |= F_ERR;
-		return -1;
-	}
+	if (f->seek(f, off, whence) < 0) return -1;
 
 	/* If seek succeeded, file is seekable and we discard read buffer. */
 	f->rpos = f->rend = 0;