[libxml2] Set memory limit for LZMA decompression

[Nick Wellnhofer <nwellnhof src gnome org>]

commit e2a9122b8dde53d320750451e9907a7dcb2ca8bb
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Sep 7 18:36:01 2017 +0200

    Set memory limit for LZMA decompression
    
    Otherwise malicious LZMA compressed files could consume large amounts
    of memory when decompressed.
    
    According to the xz man page, files compressed with `xz -9` currently
    require 65 MB to decompress, so set the limit to 100 MB.
    
    Should fix bug 786696.

 xzlib.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/xzlib.c b/xzlib.c
index 782957f..f43632b 100644
--- a/xzlib.c
+++ b/xzlib.c
@@ -408,7 +408,7 @@ xz_head(xz_statep state)
         state->strm = init;
         state->strm.avail_in = 0;
         state->strm.next_in = NULL;
-        if (lzma_auto_decoder(&state->strm, UINT64_MAX, 0) != LZMA_OK) {
+        if (lzma_auto_decoder(&state->strm, 100000000, 0) != LZMA_OK) {
             xmlFree(state->out);
             xmlFree(state->in);
             state->size = 0;