Fetch libappimage with FetchContent

Author: TheAssassin

.gitmodules

@@ -10,6 +10,3 @@
 [submodule "lib/--force"]
 	path = lib/--force
 	url = https://github.com/arsenm/sanitizers-cmake
-[submodule "lib/libappimage"]
-	path = lib/libappimage
-	url = https://github.com/AppImage/libappimage.git

CMakeLists.txt

@@ -52,6 +52,18 @@ option(USE_SYSTEM_LIBAPPIMAGE OFF "Use existing libappimage installed on system
 if(USE_SYSTEM_LIBAPPIMAGE)
     # note: find_package calls must be made in the same or a parent scope
     find_package(libappimage REQUIRED)
+else()
+    function(import_libappimage)
+        include(FetchContent)
+
+        FetchContent_Declare(libappimage
+            GIT_REPOSITORY https://github.com/AppImageCommunity/libappimage
+            GIT_TAG 3467b20
+        )
+        FetchContent_MakeAvailable(libappimage)
+    endfunction()
+
+    import_libappimage()
 endif()
 
 option(BUILD_QT_UI OFF "Build Qt UI (widget library and demo application)")

lib/CMakeLists.txt

@@ -1,7 +1,3 @@
 if(NOT USE_SYSTEM_ZSYNC2)
     add_subdirectory(zsync2 EXCLUDE_FROM_ALL)
 endif()
-
-if(NOT USE_SYSTEM_LIBAPPIMAGE)
-    add_subdirectory(libappimage EXCLUDE_FROM_ALL)
-endif()