In file : https://git.gnome.org/browse/libxml2/tree/xmlschemastypes.c

Line no: 245

static xmlSchemaFacetPtr
xmlSchemaNewMinLengthFacet(int value)
{
    ------ Some Code -----
    ret->val = xmlSchemaNewValue(XML_SCHEMAS_NNINTEGER);
    ret->val->value.decimal.lo = value;
    return (ret);
}

Here, function xmlSchemaNewValue can return NULL explicitly.
So, when ret->val is dereferenced in next line, it may cause crash.

So, it should be modified as below:

if (ret->val) ret->val->value.decimal.lo = value;
return(ret);