Add nullable parameter to readEmbeddedBuffer.

To support reading embedded buffers that can be
nullptr (currently only in empty hidl_vec).

Bug: 34255213
Test: hidl_test_java
Change-Id: I72028f580b7863b6bfeb31a5c0f43deed36dfd64

2 files changed, 9 insertions, 4 deletions

diff --git a/core/java/android/os/HwParcel.java b/core/java/android/os/HwParcel.java
index c7612d16d0c0..a265dd08a92f 100644
--- a/core/java/android/os/HwParcel.java
+++ b/core/java/android/os/HwParcel.java
@@ -212,7 +212,7 @@ public class HwParcel {
     public native final HwBlob readBuffer();
 
     public native final HwBlob readEmbeddedBuffer(
-            long parentHandle, long offset);
+            long parentHandle, long offset, boolean nullable);
 
     public native final void writeBuffer(HwBlob blob);
 
diff --git a/core/jni/android_os_HwParcel.cpp b/core/jni/android_os_HwParcel.cpp
index aefdc84b1912..1bd233313ca3 100644
--- a/core/jni/android_os_HwParcel.cpp
+++ b/core/jni/android_os_HwParcel.cpp
@@ -822,7 +822,8 @@ static jobject JHwParcel_native_readBuffer(JNIEnv *env, jobject thiz) {
 }
 
 static jobject JHwParcel_native_readEmbeddedBuffer(
-        JNIEnv *env, jobject thiz, jlong parentHandle, jlong offset) {
+        JNIEnv *env, jobject thiz, jlong parentHandle, jlong offset,
+        jboolean nullable) {
     hardware::Parcel *parcel =
         JHwParcel::GetNativeContext(env, thiz)->getParcel();
 
@@ -830,11 +831,15 @@ static jobject JHwParcel_native_readEmbeddedBuffer(
 
     const void *ptr;
     status_t status =
-        parcel->readEmbeddedBuffer(&childHandle, parentHandle, offset, &ptr);
+        parcel->readNullableEmbeddedBuffer(&childHandle, parentHandle, offset,
+                &ptr);
 
     if (status != OK) {
         jniThrowException(env, "java/util/NoSuchElementException", NULL);
         return 0;
+    } else if (status == OK && !nullable && ptr == nullptr) {
+        jniThrowException(env, "java/lang/NullPointerException", NULL);
+        return 0;
     }
 
     return JHwBlob::NewObject(env, ptr, childHandle);
@@ -945,7 +950,7 @@ static JNINativeMethod gMethods[] = {
     { "readBuffer", "()L" PACKAGE_PATH "/HwBlob;",
         (void *)JHwParcel_native_readBuffer },
 
-    { "readEmbeddedBuffer", "(JJ)L" PACKAGE_PATH "/HwBlob;",
+    { "readEmbeddedBuffer", "(JJZ)L" PACKAGE_PATH "/HwBlob;",
         (void *)JHwParcel_native_readEmbeddedBuffer },
 
     { "writeBuffer", "(L" PACKAGE_PATH "/HwBlob;)V",