Fixes Defaults added in PR#226 not working for empty ENV Variables

Paths are only set if ENV is defined.

cmake/FindBSP.cmake

@@ -262,8 +262,9 @@ foreach(COMP ${BSP_FIND_COMPONENTS})
     set(FAMILY ${CMAKE_MATCH_1})
     string(TOLOWER ${FAMILY} FAMILY_L)
     
-    if(NOT STM32_CUBE_${FAMILY}_PATH)
+    if((NOT STM32_CUBE_${FAMILY}_PATH) AND (DEFINED ENV{STM32_CUBE_${FAMILY}_PATH))
         set(STM32_CUBE_${FAMILY}_PATH $ENV{STM32_CUBE_${FAMILY}_PATH} CACHE PATH "Path to STM32Cube${FAMILY}")
+        message(STATUS "ENV STM32_CUBE_${FAMILY}_PATH specified, using STM32_CUBE_${FAMILY}_PATH: ${STM32_CUBE_${FAMILY}_PATH}")
     endif()
 
     if(NOT STM32_CUBE_${FAMILY}_PATH)

cmake/FindCMSIS.cmake

@@ -71,13 +71,14 @@ foreach(COMP ${CMSIS_FIND_COMPONENTS})
     
     string(TOLOWER ${FAMILY} FAMILY_L)
     
-    if((NOT STM32_CMSIS_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH))
+    if((NOT STM32_CMSIS_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH) AND (DEFINED ENV{STM32_CUBE_${FAMILY}_PATH}))
         set(STM32_CUBE_${FAMILY}_PATH $ENV{STM32_CUBE_${FAMILY}_PATH} CACHE PATH "Path to STM32Cube${FAMILY}")
+        message(STATUS "ENV STM32_CUBE_${FAMILY}_PATH specified, using STM32_CUBE_${FAMILY}_PATH: ${STM32_CUBE_${FAMILY}_PATH}")
     endif()
 
     if((NOT STM32_CMSIS_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH))
         set(STM32_CUBE_${FAMILY}_PATH /opt/STM32Cube${FAMILY} CACHE PATH "Path to STM32Cube${FAMILY}")
-        message(STATUS "Neither STM32_CUBE_${FAMILY}_PATH nor STM32_CMSIS_${FAMILY}_PATH specified using default  STM32_CUBE_${FAMILY}_PATH: ${STM32_CUBE_${FAMILY}_PATH}")
+        message(STATUS "Neither STM32_CUBE_${FAMILY}_PATH nor STM32_CMSIS_${FAMILY}_PATH specified using default STM32_CUBE_${FAMILY}_PATH: ${STM32_CUBE_${FAMILY}_PATH}")
     endif()
         
     find_path(CMSIS_${FAMILY}${CORE_U}_CORE_PATH

cmake/FindFreeRTOS.cmake

@@ -7,8 +7,9 @@ list(REMOVE_DUPLICATES FreeRTOS_FIND_COMPONENTS)
 
 set(FreeRTOS_HEAPS 1 2 3 4 5)
 
-if(NOT FREERTOS_PATH)
+if((NOT FREERTOS_PATH) AND (DEFINED ENV{FREERTOS_PATH}))
     set(FREERTOS_PATH $ENV{FREERTOS_PATH} CACHE PATH "Path to FreeRTOS")
+    message(STATUS "ENV FREERTOS_PATH specified, using FREERTOS_PATH: ${FREERTOS_PATH}")
 endif()
 
 if(NOT FREERTOS_PATH)

cmake/FindHAL.cmake

@@ -237,8 +237,9 @@ foreach(COMP ${HAL_FIND_COMPONENTS_FAMILIES})
     set(FAMILY ${CMAKE_MATCH_1})
     string(TOLOWER ${FAMILY} FAMILY_L)
     
-    if((NOT STM32_HAL_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH))
+    if((NOT STM32_HAL_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH) AND (DEFINED ENV{STM32_CUBE_${FAMILY}_PATH}))
         set(STM32_CUBE_${FAMILY}_PATH $ENV{STM32_CUBE_${FAMILY}_PATH} CACHE PATH "Path to STM32Cube${FAMILY}")
+        message(STATUS "ENV STM32_CUBE_${FAMILY}_PATH specified, using STM32_CUBE_${FAMILY}_PATH: ${STM32_CUBE_${FAMILY}_PATH}")
     endif()
 
     if((NOT STM32_HAL_${FAMILY}_PATH) AND (NOT STM32_CUBE_${FAMILY}_PATH))