libxslt: fix CVE-2019-18197

Use patch from upstream after 1.1.33 release.

(From OE-Core rev: 1263db2759b88e423bb717cc0cfc256c7962871b)

Signed-off-by: Joe Slater <joe.slater@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/libxslt/files/CVE-2019-18197.patch

@@ -0,0 +1,33 @@
+libxslt: fix CVE-2019-18197
+
+Added after 1.1.33 release.
+
+CVE: CVE-2019-18197
+Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxslt.git]
+Signed-off-by: Joe Slater <joe.slater@windriver.com>
+
+commit 2232473733b7313d67de8836ea3b29eec6e8e285
+Author: Nick Wellnhofer <wellnhofer@aevum.de>
+Date:   Sat Aug 17 16:51:53 2019 +0200
+
+    Fix dangling pointer in xsltCopyText
+    
+    xsltCopyText didn't reset ctxt->lasttext in some cases which could
+    lead to various memory errors in relation with CDATA sections in input
+    documents.
+    
+    Found by OSS-Fuzz.
+
+diff --git a/libxslt/transform.c b/libxslt/transform.c
+index 95ebd07..d7ab0b6 100644
+--- a/libxslt/transform.c
++++ b/libxslt/transform.c
+@@ -1094,6 +1094,8 @@ xsltCopyText(xsltTransformContextPtr ctxt, xmlNodePtr target,
+ 	    if ((copy->content = xmlStrdup(cur->content)) == NULL)
+ 		return NULL;
+ 	}
++
++	ctxt->lasttext = NULL;
+     } else {
+         /*
+ 	 * normal processing. keep counters to extend the text node

meta/recipes-support/libxslt/libxslt_1.1.33.bb

@@ -12,6 +12,7 @@ SRC_URI = "http://xmlsoft.org/sources/libxslt-${PV}.tar.gz \
            file://0001-Fix-security-framework-bypass.patch \
            file://CVE-2019-13117.patch \
            file://CVE-2019-13118.patch \
+           file://CVE-2019-18197.patch \
 "
 
 SRC_URI[md5sum] = "b3bd254a03e46d58f8ad1e4559cd2c2f"