Preserving forwarding of empty string arguments

Also:
- Support cmake-format on Windows
- Auto fixes some whitespace
- `CPMFindPackage` not updated

Author: CraigHutchinson

.cmake-format

@@ -1,6 +1,7 @@
 format:
   tab_size: 2
   line_width: 100
+  line_ending: auto
   dangle_parens: true
 
 parse:

cmake/CPM.cmake

@@ -506,16 +506,34 @@ function(cpm_override_fetchcontent contentName)
 endfunction()
 
 # Download and add a package from source
-function(CPMAddPackage)
+macro(CPMAddPackage)
+  set(__ARGN "${ARGN}")
+  list(LENGTH __ARGN __ARGN_Length)
+  if(__ARGN_Length EQUAL 1)
+    cpm_add_package_single_arg(${ARGN})
+  else()
+    # Forward preserving empty string arguments
+    # (https://gitlab.kitware.com/cmake/cmake/-/merge_requests/4729)
+    set(__ARGN_Quoted)
+    foreach(__ARG IN LISTS __ARGN)
+      string(APPEND __ARGN_Quoted " [==[${__ARG}]==]")
+    endforeach()
+    cmake_language(EVAL CODE "cpm_add_package_multi_arg( ${__ARGN_Quoted} )")
+  endif()
+endmacro()
+
+function(cpm_add_package_single_arg arg)
   cpm_set_policies()
+  cpm_parse_add_package_single_arg("${arg}" ARGN)
 
-  list(LENGTH ARGN argnLength)
-  if(argnLength EQUAL 1)
-    cpm_parse_add_package_single_arg("${ARGN}" ARGN)
+  # The shorthand syntax implies EXCLUDE_FROM_ALL
+  list(APPEND ARGN EXCLUDE_FROM_ALL YES)
 
-    # The shorthand syntax implies EXCLUDE_FROM_ALL and SYSTEM
-    set(ARGN "${ARGN};EXCLUDE_FROM_ALL;YES;SYSTEM;YES;")
-  endif()
+  cpm_add_package_multi_arg(${ARGN}) # Forward function arguments to CPMAddPackage()
+endfunction()
+
+function(cpm_add_package_multi_arg)
+  cpm_set_policies()
 
   set(oneValueArgs
       NAME
@@ -531,15 +549,14 @@ function(CPMAddPackage)
       DOWNLOAD_COMMAND
       FIND_PACKAGE_ARGUMENTS
       NO_CACHE
-      SYSTEM
       GIT_SHALLOW
       EXCLUDE_FROM_ALL
       SOURCE_SUBDIR
   )
 
   set(multiValueArgs URL OPTIONS)
 
-  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
+  cmake_parse_arguments(PARSE_ARGV 0 CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}")
 
   # Set default values for arguments
 
@@ -647,7 +664,7 @@ function(CPMAddPackage)
     cpm_check_if_package_already_added(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}")
     return()
   endif()
-
+  
   if(NOT CPM_ARGS_FORCE)
     if(CPM_USE_LOCAL_PACKAGES OR CPM_LOCAL_PACKAGES_ONLY)
       cpm_find_package(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" ${CPM_ARGS_FIND_PACKAGE_ARGUMENTS})
@@ -917,7 +934,13 @@ function(cpm_declare_fetch PACKAGE VERSION INFO)
     return()
   endif()
 
-  FetchContent_Declare(${PACKAGE} ${ARGN})
+  # Forward preserving empty string arguments
+  # (https://gitlab.kitware.com/cmake/cmake/-/merge_requests/4729)
+  set(__argsQuoted)
+  foreach(__item IN LISTS ARGN)
+    string(APPEND __argsQuoted " [==[${__item}]==]")
+  endforeach()
+  cmake_language(EVAL CODE "FetchContent_Declare(${PACKAGE} ${__argsQuoted} )")
 endfunction()
 
 # returns properties for a package previously defined by cpm_declare_fetch
@@ -1105,7 +1128,7 @@ function(cpm_prettify_package_arguments OUT_VAR IS_IN_COMMENT)
       GIT_SHALLOW
   )
   set(multiValueArgs OPTIONS)
-  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+  cmake_parse_arguments(PARSE_ARGV 0 CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}")
 
   foreach(oneArgName ${oneValueArgs})
     if(DEFINED CPM_ARGS_${oneArgName})