tests/lzma: Fix off-by-one in buffer size

Coverity spotted that we had an off-by-one here since we were using
`i+1`.  Fix this by adding a `-1` to the bounds check.  Also use
`sizeof()` to ensure the data and size are coupled.

Coverity CID: 1452207

Closes: #1037
Approved by: jlebon

diff --git a/tests/test-lzma.c b/tests/test-lzma.c
index b3487ee39ba6ac0e0085d665c71d327f63098112..559e9ad4fdb99f86911119d3605ae06f1ae1a0ee 100644 (file)
--- a/tests/test-lzma.c
+++ b/tests/test-lzma.c
@@ -79,13 +79,12 @@ static void
 test_lzma_random (void)
 {
   gssize i;
-  const guint32 buffer_size = 4096 + 1;
-  guint8 buffer[buffer_size];
+  guint8 buffer[4096];
   g_autoptr(GRand) r = g_rand_new ();
-  for (i = 0; i < buffer_size; i++)
+  for (i = 0; i < sizeof(buffer); i++)
     buffer[i] = g_rand_int (r);
 
-  for (i = 2; i <= buffer_size; i *= 2)
+  for (i = 2; i < (sizeof(buffer) - 1); i *= 2)
     {
       helper_test_compress_decompress (buffer, i - 1);
       helper_test_compress_decompress (buffer, i);