Support ENABLE_TLS_NATIVE_ROOTS to use system TLS CAs (#3660)

src/taskchampion-cpp/CMakeLists.txt

@@ -7,12 +7,20 @@ else()
   add_subdirectory(${CMAKE_SOURCE_DIR}/src/taskchampion-cpp/corrosion)
 endif()
 
+OPTION (ENABLE_TLS_NATIVE_ROOTS "Use the system's TLS root certificates" OFF)
+
+if (ENABLE_TLS_NATIVE_ROOTS)
+  message ("Enabling native TLS roots")
+  set(TASKCHAMPION_FEATURES "tls-native-roots")
+endif (ENABLE_TLS_NATIVE_ROOTS)
+
 # Import taskchampion-lib as a CMake library. This implements the Rust side of
 # the cxxbridge, and depends on the `taskchampion` crate.
 corrosion_import_crate(
   MANIFEST_PATH "${CMAKE_SOURCE_DIR}/Cargo.toml"
   LOCKED
-  CRATES "taskchampion-lib")
+  CRATES "taskchampion-lib"
+  FEATURES "${TASKCHAMPION_FEATURES}")
 
 # Set up `taskchampion-cpp`, the C++ side of the bridge.
 corrosion_add_cxxbridge(taskchampion-cpp

src/taskchampion-cpp/Cargo.toml

@@ -11,5 +11,9 @@ crate-type = ["staticlib"]
 taskchampion = "0.9.0"
 cxx = "1.0.124"
 
+[features]
+# use native CA roots, instead of bundled
+tls-native-roots = ["taskchampion/tls-native-roots"]
+
 [build-dependencies]
 cxx-build = "1.0"