Vendor dependencies for 0.3.0 release

vendor/jni/tests/threads_explicit_detach.rs

@@ -0,0 +1,21 @@
+#![cfg(feature = "invocation")]
+
+mod util;
+use util::{attach_current_thread, call_java_abs, detach_current_thread, jvm};
+
+#[test]
+pub fn explicit_detach_detaches_thread_attached_locally() {
+    assert_eq!(jvm().threads_attached(), 0);
+    let mut guard = attach_current_thread();
+    let val = call_java_abs(&mut guard, -1);
+    assert_eq!(val, 1);
+    assert_eq!(jvm().threads_attached(), 1);
+
+    // # Safety
+    // we won't be trying to use a pre-existing (invalid) `JNIEnv` after detaching
+    unsafe {
+        detach_current_thread();
+    }
+    assert_eq!(jvm().threads_attached(), 0);
+    assert!(jvm().get_env().is_err());
+}