diff options
Diffstat (limited to 'sharedbook.c')
| -rw-r--r-- | sharedbook.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/sharedbook.c b/sharedbook.c index 4cfde94..03c2147 100644 --- a/sharedbook.c +++ b/sharedbook.c @@ -121,7 +121,20 @@ ogg_uint32_t *_make_words(long *l,long n,long sparsecount){ }else if(sparsecount==0)count++; } - + + /* sanity check the huffman tree; an underpopulated tree must be + rejected. The only exception is the one-node pseudo-nil tree, + which appears to be underpopulated because the tree doesn't + really exist; there's only one possible 'codeword' or zero bits, + but the above tree-gen code doesn't mark that. */ + if(sparsecount != 1){ + for(i=1;i<33;i++) + if(marker[i] & (0xffffffffUL>>(32-i))){ + _ogg_free(r); + return(NULL); + } + } + /* bitreverse the words because our bitwise packer/unpacker is LSb endian */ for(i=0,count=0;i<n;i++){ |