native: Fix additional ExceptionChecks, and add EnsureLocalCapacity

IBM Semeru found additional warnings with
-Xcheck:jni:warn,pedantic,advice

Oh hey, and ignore all these warnings from java/ and sun/ packages :-b

junixsocket-native/src/main/c/filedescriptors.c

@@ -177,6 +177,9 @@ void _initFD(JNIEnv * env, jobject fd, jint handle)
     if(fieldID_fd == NULL && methodID_setFd != NULL) {
         // Android
         (*env)->CallVoidMethod(env, fd, methodID_setFd, handle);
+        if((*env)->ExceptionCheck(env)) {
+            return;
+        }
         return;
     }
 

junixsocket-native/src/main/c/init.c

@@ -131,6 +131,7 @@ jboolean supportsZeroLengthSend(void) {
 JNIEXPORT void JNICALL Java_org_newsclub_net_unix_NativeUnixSocket_init
 (JNIEnv *env, jclass clazz CK_UNUSED)
 {
+    (*env)->EnsureLocalCapacity(env, 20);
 #if defined(_WIN32)
     WSADATA wsaData;
     int ret = WSAStartup(MAKEWORD(2,2), &wsaData);

junixsocket-native/src/main/c/receive.c

@@ -181,6 +181,9 @@ static ssize_t recvmsg_wrapper(JNIEnv * env, int handle, jbyte *buf, jint length
             jmethodID kSetTipcErrorInfo = getMethodID_setTipcErrorInfo();
             if(kSetTipcErrorInfo != NULL) {
                 (*env)->CallVoidMethod(env, ancSupp, kSetTipcErrorInfo, errInfo->errorCode, errInfo->dataLength);
+                if((*env)->ExceptionCheck(env)) {
+                    return -1;
+                }
             }
         } else if(cmsg->cmsg_level == SOL_TIPC && cmsg->cmsg_type == TIPC_DESTNAME && len == 12) {
             CK_IGNORE_CAST_ALIGN_BEGIN
@@ -189,6 +192,9 @@ static ssize_t recvmsg_wrapper(JNIEnv * env, int handle, jbyte *buf, jint length
             jmethodID kSetTipcDestName = getMethodID_setTipcDestName();
             if(kSetTipcDestName != NULL) {
                 (*env)->CallVoidMethod(env, ancSupp, kSetTipcDestName, addr->type, addr->lower, addr->upper);
+                if((*env)->ExceptionCheck(env)) {
+                    return -1;
+                }
             }
 #endif
         } else {

junixsocket-native/src/main/c/reflection.c

@@ -164,7 +164,7 @@ JNIEXPORT jobject JNICALL Java_org_newsclub_net_unix_NativeUnixSocket_currentRMI
     }
     jobject connHandler = (*env)->CallObjectMethod(env, tl,
                                                    tlGet);
-    if(connHandler == NULL) {
+    if((*env)->ExceptionCheck(env) || connHandler == NULL) {
         return NULL;
     }
     jclass connHandlerClass = (*env)->GetObjectClass(env, connHandler);
@@ -194,6 +194,9 @@ JNIEXPORT void JNICALL Java_org_newsclub_net_unix_NativeUnixSocket_deregisterSel
     }
     if(kMethodRemoveKey != NULL) {
         (*env)->CallVoidMethod(env, chann, kMethodRemoveKey, key);
+        if((*env)->ExceptionCheck(env)) {
+            return;
+        }
     } else {
         // FIXME
     }