fix windows build due to protobuf find failure

Author: BewareMyPower

LegacyFindPackages.cmake

@@ -23,6 +23,14 @@ if (VCPKG_TRIPLET)
     set(CMAKE_PREFIX_PATH "${PROJECT_SOURCE_DIR}/vcpkg_installed/${VCPKG_TRIPLET}")
     message(STATUS "Use CMAKE_PREFIX_PATH: ${CMAKE_PREFIX_PATH}")
     set(PROTOC_PATH "${CMAKE_PREFIX_PATH}/tools/protobuf/protoc")
+    if (MSVC AND VCPKG_TRIPLET MATCHES ".*-static")
+        # vcpkg installs host executables (protoc, etc.) in the non-static triplet's
+        # tools directory. Derive it by stripping "-static" from the triplet name.
+        string(REPLACE "-static" "" VCPKG_HOST_TRIPLET "${VCPKG_TRIPLET}")
+        set(PROTOC_PATH "${PROJECT_SOURCE_DIR}/vcpkg_installed/${VCPKG_HOST_TRIPLET}/tools/protobuf/protoc")
+        # Set the cache variable so protobuf's CMake module compatibility shim finds it
+        set(Protobuf_PROTOC_EXECUTABLE "${PROTOC_PATH}.exe" CACHE FILEPATH "protoc executable" FORCE)
+    endif ()
     message(STATUS "Use protoc: ${PROTOC_PATH}")
     set(VCPKG_ROOT "${PROJECT_SOURCE_DIR}/vcpkg_installed/${VCPKG_TRIPLET}")
     set(VCPKG_DEBUG_ROOT "${VCPKG_ROOT}/debug")