Fix Rapidjosn CMake patching for windows (#1181)

* Add re-configuration to CI to check for fetch content apply bugs

* RapidJSON: Manually apply cmake version patch instead of using PATCH_COMMAND

PATCH_COMMAND was problematic on windows, preventing re-configuration.

* Trim trailing whitespace

.github/workflows/Ubuntu.yml

@@ -186,6 +186,11 @@ jobs:
         -DFLAMEGPU_VISUALISATION="${{ env.VISUALISATION }}"
         -DFLAMEGPU_ENABLE_NVTX="ON"
 
+    # Check for bugs when cmake is reconfigured, i.e. fetch content patching
+    - name: Re-configure cmake
+      run: >
+        cmake . -B "${{ env.BUILD_DIR }}"
+
     - name: Build static library
       working-directory: ${{ env.BUILD_DIR }}
       run: cmake --build . --target flamegpu --verbose -j `nproc`

.github/workflows/Windows.yml

@@ -146,6 +146,11 @@ jobs:
         -DFLAMEGPU_VISUALISATION="${{ env.VISUALISATION }}"
         -DFLAMEGPU_ENABLE_NVTX="ON"
 
+    # Check for bugs when cmake is reconfigured, i.e. fetch content patching
+    - name: Re-configure cmake
+      run: >
+        cmake . -B "${{ env.BUILD_DIR }}"
+
     - name: Build static library
       working-directory: ${{ env.BUILD_DIR }}
       run: cmake --build . --config ${{ env.CONFIG }} --target flamegpu --verbose -j `nproc`

cmake/dependencies/rapidjson.cmake

@@ -8,18 +8,47 @@ include(ExternalProject)
 cmake_policy(SET CMP0079 NEW)
 
 # a95e013b97ca6523f32da23f5095fcc9dd6067e5 is the last commit before a change which breaks our method of finding rapid json without running a cmake install first.
-# but we also need to patch this to avoid a cmake >= 3.26.4 deprecation
+# but we also need to patch this to avoid a cmake >= 3.26.4 deprecation, but this is handled manually post-population
 FetchContent_Declare(
     rapidjson
     GIT_REPOSITORY https://github.com/Tencent/rapidjson.git
     GIT_TAG        a95e013b97ca6523f32da23f5095fcc9dd6067e5
     GIT_PROGRESS   ON
-    PATCH_COMMAND git apply ${CMAKE_CURRENT_LIST_DIR}/patches/rapidjson-cmake-3.5-deprecation.patch || true
     # UPDATE_DISCONNECTED   ON
 )
 FetchContent_GetProperties(rapidjson)
 if(NOT rapidjson_POPULATED)
     FetchContent_Populate(rapidjson)
+    # Manually patch Rapidjson for cmake minimum version.
+    # PATCH_COMMAND that works reliably on windows was problematic.
+    # Check if the patch is applicable
+    execute_process(
+        COMMAND git apply --check ${CMAKE_CURRENT_LIST_DIR}/patches/rapidjson-cmake-3.5-deprecation.patch
+        WORKING_DIRECTORY "${rapidjson_SOURCE_DIR}"
+        RESULT_VARIABLE rapidjson_patch_check_result
+        OUTPUT_QUIET
+        ERROR_QUIET
+    )
+    if (rapidjson_patch_check_result EQUAL 0)
+        # If applicable, apply the patch
+        message(CHECK_START  "Patching RapidJSON")
+        execute_process(
+            COMMAND git apply ${CMAKE_CURRENT_LIST_DIR}/patches/rapidjson-cmake-3.5-deprecation.patch
+            WORKING_DIRECTORY "${rapidjson_SOURCE_DIR}"
+            RESULT_VARIABLE rapidjson_patch_result
+            OUTPUT_QUIET
+            ERROR_QUIET
+        )
+        # If the patch failed emit a Warnign but allow cmake to progress. This should not occur given the previous check. 
+        if (rapidjson_patch_check_result EQUAL 0)
+            message(CHECK_PASS "done")
+        else()
+            message(CHECK_FAIL "patching failed")
+        endif()
+        unset(rapidjson_patch_result)
+    endif()
+    unset(rapidjson_patch_check_result)
+
     # RapidJSON has custom RapidJSONConfig.cmake, generated by cmake configure/generate
     execute_process(
     COMMAND ${CMAKE_COMMAND} . -DRAPIDJSON_BUILD_DOC=OFF -DRAPIDJSON_BUILD_EXAMPLES=OFF -DRAPIDJSON_BUILD_TESTS=OFF -DRAPIDJSON_BUILD_THIRDPARTY_GTEST=OFF -Wno-deprecated
@@ -49,5 +78,5 @@ mark_as_advanced(FETCHCONTENT_SOURCE_DIR_RAPIDJSON)
 mark_as_advanced(FETCHCONTENT_QUIET)
 mark_as_advanced(FETCHCONTENT_BASE_DIR)
 mark_as_advanced(FETCHCONTENT_FULLY_DISCONNECTED)
-mark_as_advanced(FETCHCONTENT_UPDATES_DISCONNECTED) 
-mark_as_advanced(FETCHCONTENT_UPDATES_DISCONNECTED_RAPIDJSON) 
+mark_as_advanced(FETCHCONTENT_UPDATES_DISCONNECTED)
+mark_as_advanced(FETCHCONTENT_UPDATES_DISCONNECTED_RAPIDJSON)