new test for relocaiton of cmake_find_none (#18819)

* new test for relocaiton of cmake_find_none

* wip

* wip

* working!

* some logs

* wip

* print version

* cmake version?

* cleanup

* using list(APPEND, better regex

* renamed to CONAN_ variable

Author: memsharded

conan/tools/cmake/cmakedeps2/cmakedeps.py

@@ -203,6 +203,11 @@ def generate(self):
         {% for pkg_name, folder in pkg_paths.items() %}
         set({{pkg_name}}_DIR "{{folder}}")
         {% endfor %}
+        {% for pkg_name, folders in pkg_paths_multi.items() %}
+        {% for folder in folders %}
+        list(APPEND CONAN_{{pkg_name}}_DIR_MULTI "{{folder}}")
+        {% endfor %}
+        {% endfor %}
         {% if host_runtime_dirs %}
         set(CONAN_RUNTIME_LIB_DIRS {{ host_runtime_dirs }} )
         # Only for VS, needs CMake>=3.27
@@ -234,6 +239,17 @@ def generate(self):
         # if not, test_cmake_add_subdirectory test fails
         # content.append('set(CMAKE_FIND_PACKAGE_PREFER_CONFIG ON)')
         pkg_paths = {}
+
+        pkg_paths_multi = {}
+        if os.path.exists(self._conan_cmakedeps_paths):
+            existing_toolchain = load(self._conan_cmakedeps_paths)
+            pattern_paths = r"list\(APPEND CONAN_([A-Za-z0-9-_]*)_DIR_MULTI \"([^)]*)\"\)"
+            variable_match = re.findall(pattern_paths, existing_toolchain)
+            for (captured_name, captured_path) in variable_match:
+                path_list = pkg_paths_multi.setdefault(captured_name, [])
+                if captured_path not in path_list:
+                    path_list.append(captured_path)
+
         for req, dep in all_reqs:
             cmake_find_mode = self._cmakedeps.get_property("cmake_find_mode", dep)
             cmake_find_mode = cmake_find_mode or FIND_MODE_CONFIG
@@ -255,6 +271,10 @@ def generate(self):
                         if os.path.isfile(os.path.join(pkg_folder, filename)):
                             pkg_paths[pkg_name] = relativize_path(pkg_folder, self._conanfile,
                                                                   "${CMAKE_CURRENT_LIST_DIR}")
+
+                    existing_paths = pkg_paths_multi.setdefault(pkg_name, [])
+                    if pkg_folder not in existing_paths:
+                        existing_paths.append(pkg_folder)
                 continue
 
             # If CMakeDeps generated, the folder is this one
@@ -269,6 +289,7 @@ def generate(self):
         cmake_module_path = self._get_cmake_paths(all_reqs, "builddirs")
         context = {"host_runtime_dirs": self._get_host_runtime_dirs(),
                    "pkg_paths": pkg_paths,
+                   "pkg_paths_multi": pkg_paths_multi,
                    "cmake_program_path": _join_paths(self._conanfile, cmake_program_path),
                    "cmake_library_path": _join_paths(self._conanfile, cmake_library_path),
                    "cmake_include_path": _join_paths(self._conanfile, cmake_include_path),