[vcpkg_apply_patches] Work around /etc/gitconfig: Permission denied (#…

…14848)

Co-authored-by: Robert Schumacher <[email protected]>

scripts/cmake/vcpkg_apply_patches.cmake

@@ -37,6 +37,12 @@ function(vcpkg_apply_patches)
     cmake_parse_arguments(PARSE_ARGV 0 _ap "QUIET" "SOURCE_PATH" "PATCHES")
 
     find_program(GIT NAMES git git.cmd)
+    if(DEFINED ENV{GIT_CONFIG_NOSYSTEM})
+        set(GIT_CONFIG_NOSYSTEM_BACKUP "$ENV{GIT_CONFIG_NOSYSTEM}")
+    else()
+        unset(GIT_CONFIG_NOSYSTEM_BACKUP)
+    endif()
+    set(ENV{GIT_CONFIG_NOSYSTEM} 1)
     set(PATCHNUM 0)
     foreach(PATCH ${_ap_PATCHES})
         get_filename_component(ABSOLUTE_PATCH "${PATCH}" ABSOLUTE BASE_DIR "${CURRENT_PORT_DIR}")
@@ -57,4 +63,9 @@ function(vcpkg_apply_patches)
 
         math(EXPR PATCHNUM "${PATCHNUM}+1")
     endforeach()
+    if(DEFINED GIT_CONFIG_NOSYSTEM_BACKUP)
+        set(ENV{GIT_CONFIG_NOSYSTEM} "${GIT_CONFIG_NOSYSTEM_BACKUP}")
+    else()
+        unset(ENV{GIT_CONFIG_NOSYSTEM})
+    endif()
 endfunction()