Add an error check for correct formatting in Deflate uncompressed

block headers. (Ubuntu 12.04's gcc spotted that nlen was unused, which
it shouldn't have been.)

[originally from svn r9475]

1 files changed, 5 insertions, 1 deletions

diff --git a/deflate.c b/deflate.c
index ecae0d0..a04f86d 100644
--- a/deflate.c
+++ b/deflate.c
@@ -2441,8 +2441,12 @@ int deflate_decompress_data(deflate_decompress_ctx *dctx,
 	     */
 	    if (dctx->nbits < 16)
 		goto finished;
-	    nlen = dctx->bits & 0xFFFF;
+	    nlen = 0xFFFF & ~dctx->bits;
 	    EATBITS(16);
+	    if (dctx->uncomplen != (nlen ^ 0xFFFF)) {
+                error = DEFLATE_ERR_UNCOMP_HDR;
+                goto finished;
+            }
 	    if (dctx->uncomplen == 0)
 		dctx->state = OUTSIDEBLK;	/* block is empty */
 	    else