+ if (Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE] == NULL) {\r
+ //\r
+ // This should never happen in a correctly configured DHCP / PXE\r
+ // environment. One misconfiguration that can cause it is two DHCP servers\r
+ // mistakenly running on the same network segment at the same time, and\r
+ // racing each other in answering DHCP requests. Thus, the DHCP packets\r
+ // that the edk2 PXE client considers "belonging together" may actually be\r
+ // entirely independent, coming from two (competing) DHCP servers.\r
+ //\r
+ // Try to deal with this gracefully. Note that this check is not\r
+ // comprehensive, as we don't try to identify all such errors.\r
+ //\r
+ return EFI_PROTOCOL_ERROR;\r
+ }\r