Add OndselSolver as git submodule

also update github actions to pull submodules

.github/workflows/sub_buildUbuntu2004.yml

@@ -73,6 +73,8 @@ jobs:
     steps:
       - name: Checking out source code
         uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: Install FreeCAD dependencies
         run: |
           sudo apt-get update -qq

.github/workflows/sub_buildUbuntu2204.yml

@@ -71,6 +71,8 @@ jobs:
     steps:
       - name: Checking out source code
         uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: Install FreeCAD dependencies
         run: |
           sudo apt-get update -qq

.github/workflows/sub_buildWindows.yml

@@ -64,6 +64,8 @@ jobs:
     steps:
       - name: Checking out source code
         uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: Make needed directories, files and initializations
         id: Init
         run: |

.github/workflows/sub_lint.yml

@@ -199,6 +199,8 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v3
+        with:
+          submodules: true
       - name: Make needed directories, files and initializations
         id: Init
         run: |

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "src/3rdParty/OndselSolver"]
+	path = src/3rdParty/OndselSolver
+	url = https://github.com/Ondsel-Development/OndselSolver.git

cMake/FreeCAD_Helpers/InitializeFreeCADBuildOptions.cmake

@@ -9,6 +9,7 @@ macro(InitializeFreeCADBuildOptions)
     option(FREECAD_USE_EXTERNAL_SMESH "Use system installed smesh instead of the bundled." OFF)
     option(FREECAD_USE_EXTERNAL_KDL "Use system installed orocos-kdl instead of the bundled." OFF)
     option(FREECAD_USE_EXTERNAL_FMT "Use system installed fmt library if available instead of fetching the source." ON)
+    option(FREECAD_USE_EXTERNAL_ONDSELSOLVER "Use system installed OndselSolver instead of git submodule." OFF)
     option(FREECAD_USE_FREETYPE "Builds the features using FreeType libs" ON)
     option(FREECAD_BUILD_DEBIAN "Prepare for a build of a Debian package" OFF)
     option(BUILD_WITH_CONDA "Set ON if you build FreeCAD with conda" OFF)

src/3rdParty/CMakeLists.txt

@@ -4,4 +4,12 @@ if (BUILD_SMESH AND NOT FREECAD_USE_EXTERNAL_SMESH)
 endif()
 
 add_subdirectory(lazy_loader)
-add_subdirectory(libE57Format)
+add_subdirectory(libE57Format)
+
+if (BUILD_ASSEMBLY AND NOT FREECAD_USE_EXTERNAL_ONDSELSOLVER)
+    if( NOT EXISTS "${CMAKE_SOURCE_DIR}/src/3rdParty/OndselSolver/CMakeLists.txt" )
+        message( SEND_ERROR "The OndselSolver git submodule is not available. Please run
+        git submodule update --init" )
+    endif()
+    add_subdirectory(OndselSolver)
+endif()