Check that cert path flags are set before prepending an absolute path (#1127)

Author: yourslab

demos/CMakeLists.txt

@@ -55,13 +55,13 @@ endif()
 
 # Set prefix to PWD if any path flags are relative
 if(DEFINED ENV{PWD})
-    if(NOT ROOT_CA_CERT_PATH MATCHES "/$")
+    if(ROOT_CA_CERT_PATH AND NOT ROOT_CA_CERT_PATH MATCHES "/$")
         set(ROOT_CA_CERT_PATH "$ENV{PWD}/${ROOT_CA_CERT_PATH}")
     endif()
-    if(NOT CLIENT_CERT_PATH MATCHES "/$")
+    if(CLIENT_CERT_PATH AND NOT CLIENT_CERT_PATH MATCHES "/$")
         set(CLIENT_CERT_PATH "$ENV{PWD}/${CLIENT_CERT_PATH}")
     endif()
-    if(NOT CLIENT_PRIVATE_KEY_PATH MATCHES "/$")
+    if(CLIENT_PRIVATE_KEY_PATH AND NOT CLIENT_PRIVATE_KEY_PATH MATCHES "/$")
         set(CLIENT_PRIVATE_KEY_PATH "$ENV{PWD}/${CLIENT_PRIVATE_KEY_PATH}")
     endif()
 endif()