check length of generated data stream in io-read-single, to avoid

exposing libogg to uninitialized packet data


git-svn-id: http://svn.annodex.net/liboggz/trunk@526 8158c8cd-e7e1-0310-9fa4-c5954c97daef

src/tests/io-read-single.c

@@ -43,6 +43,7 @@
 #define DATA_BUF_LEN 1024
 
 static long serialno;
+static long bytes_generated = 0;
 static int read_called = 0;
 static int eof_reached = 0;
 
@@ -135,7 +136,7 @@ my_io_read (void * user_handle, void * buf, size_t n)
   /* Mark that the read IO method was actually used */
   read_called++;
 
-  len = MIN (n, DATA_BUF_LEN - offset);
+  len = MIN (n, bytes_generated - offset);
 
   memcpy (buf, &data_buf[offset], len);
 
@@ -177,6 +178,8 @@ main (int argc, char * argv[])
   if (n >= DATA_BUF_LEN)
     FAIL("Too much data generated by writer");
 
+  bytes_generated = n;
+
   do {
     ret = oggz_read (reader, 4);
   } while (ret > 0 || ret == OGGZ_ERR_READ_STOP_OK);