Prevent inactive GT EU P2P outputs from injecting energy (#1667)

dependencies.gradle

@@ -71,7 +71,7 @@ dependencies {
         exclude module: "waila"
     }
 
-    //runtimeOnlyNonPublishable('com.github.GTNewHorizons:GT5-Unofficial:5.09.54.151:dev') {
+    //runtimeOnlyNonPublishable('com.github.GTNewHorizons:GT5-Unofficial:5.09.54.188:dev') {
     //    exclude module: "Applied-Energistics-2-Unofficial"
     //    exclude module: "Hodgepodge"
     //    exclude module: "waila"

src/main/java/appeng/gametests/network/p2p/GTEUP2PTests.java

@@ -0,0 +1,88 @@
+package appeng.gametests.network.p2p;
+
+import static appeng.gametests.AEGameTestHelpers.assertActive;
+import static appeng.gametests.AEGameTestHelpers.assertInactive;
+import static appeng.gametests.AEGameTestHelpers.part;
+
+import net.minecraft.tileentity.TileEntity;
+import net.minecraftforge.common.util.ForgeDirection;
+
+import com.gtnewhorizons.horizonqa.api.GameTestHelper;
+import com.gtnewhorizons.horizonqa.api.annotation.GameTest;
+import com.gtnewhorizons.horizonqa.api.annotation.GameTestHolder;
+
+import appeng.core.AppEng;
+import appeng.me.GridAccessException;
+import appeng.parts.automation.PartLevelEmitter;
+import appeng.parts.p2p.PartP2PGT5Power;
+import appeng.tile.networking.TileCableBus;
+import appeng.tile.networking.TileCreativeEnergyController;
+import gregtech.api.interfaces.tileentity.IBasicEnergyContainer;
+
+@GameTestHolder(value = AppEng.MOD_ID, requiredMods = "gregtech")
+public class GTEUP2PTests {
+
+    private static final ForgeDirection[] LOAD_SIDES = { ForgeDirection.NORTH, ForgeDirection.SOUTH, ForgeDirection.UP,
+            ForgeDirection.DOWN };
+
+    @GameTest(template = "gt_eu_p2p_no_channel", timeoutTicks = 120)
+    public static void outputWithoutChannelDoesNotInjectEU(GameTestHelper helper) {
+        TileCreativeEnergyController controller = helper
+                .assertTileEntityPresent(TileCreativeEnergyController.class, "controller");
+        PartP2PGT5Power input = part(helper, "input_tunnel_host", PartP2PGT5Power.class);
+        PartP2PGT5Power output = part(helper, "output_tunnel_host", PartP2PGT5Power.class);
+        TileEntity receiver = helper.assertTileEntityPresent(TileEntity.class, "energy_hatch");
+        helper.assertTrue(receiver instanceof IBasicEnergyContainer, "Receiver should be a GT energy container");
+        IBasicEnergyContainer hatch = (IBasicEnergyContainer) receiver;
+
+        helper.startSequence().thenWaitUntil("wait for the input and channel load to become active", 80, () -> {
+            assertActive(helper, controller.getProxy(), "Carrier controller should be active");
+            assertActive(helper, input, "GT EU P2P input should have a channel");
+            assertChannelLoad(helper, "channel_load_1");
+            assertChannelLoad(helper, "channel_load_2");
+            assertInactive(helper, output, "GT EU P2P output should have no channel behind eight level emitters");
+            helper.assertSame(
+                    input.getGridNode().getGrid(),
+                    output.getGridNode().getGrid(),
+                    "Input and channel-starved output should remain on the same carrier grid");
+            helper.assertFalse(input.isOutput(), "GT EU P2P input should remain in input mode");
+            helper.assertTrue(output.isOutput(), "GT EU P2P output should remain in output mode");
+            helper.assertTrue(input.getFrequency() != 0, "GT EU P2P pair should have a nonzero frequency");
+            helper.assertEquals(input.getFrequency(), output.getFrequency(), "GT EU P2P pair should stay linked");
+            helper.assertEquals(ForgeDirection.EAST, output.getSide(), "GT EU P2P output should face the hatch");
+            assertInputEnumeratesOutput(input, output);
+            helper.assertEquals(32L, hatch.getInputVoltage(), "Receiver should accept LV voltage");
+            helper.assertTrue(
+                    hatch.inputEnergyFrom(ForgeDirection.WEST),
+                    "Energy Hatch should accept EU from the west");
+            helper.assertEquals(0L, hatch.getStoredEU(), "Energy Hatch should start empty");
+        }).thenExecute("inject one LV amp into the installed GT EU P2P input", () -> {
+            long acceptedAmperes = input.injectEnergyUnits(32L, 1L);
+            helper.assertEquals(0L, acceptedAmperes, "Input should reject EU when its only output has no channel");
+            helper.assertEquals(0L, hatch.getStoredEU(), "Channel-starved output should deliver no EU to the hatch");
+        }).thenSucceed();
+    }
+
+    private static void assertChannelLoad(GameTestHelper helper, String label) {
+        TileCableBus host = helper.assertTileEntityPresent(TileCableBus.class, label);
+        for (ForgeDirection side : LOAD_SIDES) {
+            helper.assertTrue(
+                    host.getPart(side) instanceof PartLevelEmitter,
+                    label + " should have a level emitter on " + side);
+            assertActive(helper, host.getPart(side), label + " level emitter should consume a channel on " + side);
+        }
+    }
+
+    private static void assertInputEnumeratesOutput(PartP2PGT5Power input, PartP2PGT5Power output) {
+        try {
+            for (PartP2PGT5Power candidate : input.getOutputs()) {
+                if (candidate == output) {
+                    return;
+                }
+            }
+        } catch (GridAccessException e) {
+            throw new AssertionError("GT EU P2P input should access the carrier P2P cache", e);
+        }
+        throw new AssertionError("GT EU P2P input should enumerate the channel-starved output");
+    }
+}

src/main/java/appeng/parts/p2p/PartP2PGT5Power.java

@@ -157,7 +157,7 @@ public class PartP2PGT5Power extends PartP2PTunnelNormal<PartP2PGT5Power> implem
     }
 
     private long doOutput(long aVoltage, long aAmperage) {
-        if (!this.isOutput()) {
+        if (!this.isOutput() || !this.getProxy().isActive()) {
             return 0L;
         } else {
             TileEntity te = this.getTarget();

src/main/resources/assets/appliedenergistics2/horizonqastructures/gt_eu_p2p_no_channel.json

@@ -0,0 +1,36 @@
+{
+  "format_version": 2,
+  "size": [6, 3, 3],
+  "palette": {
+    "A": {"name": "appliedenergistics2:tile.BlockCableBus", "meta": 0, "label": "AE2 Cable and/or Bus"},
+    "B": {"name": "appliedenergistics2:tile.BlockCreativeEnergyController", "meta": 1, "label": "ME Self-Powered Controller"},
+    "C": {"name": "gregtech:gt.blockmachines", "meta": 1, "label": "Bronze Hull"}
+  },
+  "layers": [
+    [
+      "......",
+      "......",
+      "......"
+    ],
+    [
+      "......",
+      "ABAAAC",
+      "......"
+    ],
+    [
+      "......",
+      "......",
+      "......"
+    ]
+  ],
+  "annotations": {
+    "labels": {
+      "channel_load_1": [2, 1, 1],
+      "channel_load_2": [3, 1, 1],
+      "controller": [1, 1, 1],
+      "energy_hatch": [5, 1, 1],
+      "input_tunnel_host": [0, 1, 1],
+      "output_tunnel_host": [4, 1, 1]
+    }
+  }
+}