Add nullptr check conditions

Author: airween

apache2/msc_xml.c

@@ -238,15 +238,17 @@ int xml_process_chunk(modsec_rec *msr, const char *buf, unsigned int size, char
 
         /* Not a first invocation. */
         msr_log(msr, 4, "XML: Continue parsing.");
-        if (msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_ONLYARGS) {
+        if (msr->xml->parsing_ctx != NULL &&
+            msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_ONLYARGS) {
             xmlParseChunk(msr->xml->parsing_ctx, buf, size, 0);
             if (msr->xml->parsing_ctx->wellFormed != 1) {
                 *error_msg = apr_psprintf(msr->mp, "XML: Failed parsing document.");
                 return -1;
             }
         }
 
-        if (msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_OFF) {
+        if (msr->xml->parsing_ctx_arg != NULL &&
+            msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_OFF) {
             if (xmlParseChunk(msr->xml->parsing_ctx_arg, buf, size, 0) != 0) {
                 if (msr->xml->xml_error) {
                     *error_msg = msr->xml->xml_error;
@@ -276,7 +278,8 @@ int xml_complete(modsec_rec *msr, char **error_msg) {
 
     /* Only if we have a context, meaning we've done some work. */
     if (msr->xml->parsing_ctx != NULL || msr->xml->parsing_ctx_arg != NULL) {
-        if (msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_ONLYARGS) {
+        if (msr->xml->parsing_ctx != NULL &&
+            msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_ONLYARGS) {
             /* This is how we signalise the end of parsing to libxml. */
             xmlParseChunk(msr->xml->parsing_ctx, NULL, 0, 1);
 
@@ -295,7 +298,8 @@ int xml_complete(modsec_rec *msr, char **error_msg) {
             }
         }
 
-        if (msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_OFF) {
+        if (msr->xml->parsing_ctx_arg != NULL &&
+            msr->txcfg->parse_xml_into_args != MSC_XML_ARGS_OFF) {
             if (xmlParseChunk(msr->xml->parsing_ctx_arg, NULL, 0, 1) != 0) {
                 if (msr->xml->xml_error) {
                     *error_msg = msr->xml->xml_error;