curl andy roid is already considered to be unix

Externals/curl/CMakeLists.txt

@@ -1,20 +1,47 @@
 set(BUILD_CURL_EXE OFF)
+set(BUILD_EXAMPLES OFF)
+set(BUILD_LIBCURL_DOCS OFF)
+set(BUILD_MISC_DOCS OFF)
 set(BUILD_SHARED_LIBS OFF)
 set(BUILD_STATIC_LIBS ON)
-set(BUILD_TESTS OFF)
-set(BUILD_EXAMPLES OFF)
+set(BUILD_TESTING OFF)
 set(CURL_ENABLE_EXPORT_TARGET OFF)
 
+set(HTTP_ONLY ON)
+
+set(CURL_USE_LIBPSL OFF)
+set(CURL_USE_LIBSSH2 OFF)
+set(CURL_ZLIB OFF CACHE BOOL "" FORCE)
+set(CURL_ZSTD OFF)
+set(USE_LIBIDN2 OFF)
+set(USE_NGHTTP2 OFF)
+
+if(UNIX)
+  # We use mbedtls on Unix(-like) systems and Android.
+  set(CURL_USE_OPENSSL OFF)
+
+  if(MBEDTLS_FOUND)
+    # There's mbedtls on the system, so we can just enable CURL_USE_MBEDTLS.
+    set(CURL_USE_MBEDTLS ON)
+  else()
+    # HACK: Set some internal variables to pretend like mbedtls was found on the system.
+    # We can't use CURL_USE_MBEDTLS with our copy from Externals, as that flag expects
+    # mbedtls to be installed (the CMakeLists attempts to search for it with find_package).
+    set(_ssl_enabled ON)
+    set(USE_MBEDTLS ON)
+    set(_curl_ca_bundle_supported TRUE)
+  endif()
+endif()
+
 if(WIN32)
   set(CURL_USE_SCHANNEL ON)
 endif()
 
-if(UNIX)
-  set(CURL_USE_MBEDTLS ON)
-endif()
-
-if(APPLE)
-  set(USE_APPLE_IDN ON)
-endif()
-
 add_subdirectory(curl)
+
+if(UNIX AND NOT MBEDTLS_FOUND)
+  # HACK: Manually link with the mbedtls libraries.
+  target_link_libraries(libcurl_static PRIVATE
+    MbedTLS::mbedtls
+    MbedTLS::mbedx509)
+endif()