Update gradle wrapper

Update MCPConfig to version that bypasses javac compiler bugs
Fix Global loot test compile errors.

Jenkinsfile

@@ -18,11 +18,13 @@ pipeline {
     }
 
     stages {
+        /* This resets the checkout on jenkins, but doesn't take branch into account... 
         stage('fetch') {
             steps {
                 checkout scm
             }
         }
+        */
         stage('notify_start') {
             when {
                 not {

build.gradle

@@ -52,6 +52,8 @@ plugins {
 }
 apply plugin: 'eclipse'
 
+println('Java: ' + System.getProperty('java.version') + ' JVM: ' + System.getProperty('java.vm.version'))
+
 ext {
     JAR_SIGNER = null
     if (project.hasProperty('keystore')) {
@@ -64,7 +66,7 @@ ext {
     MAPPING_CHANNEL = 'snapshot'
     MAPPING_VERSION = '20200225-1.15.1'
     MC_VERSION = '1.15.2'
-    MCP_VERSION = '20200122.131323'
+    MCP_VERSION = '20200307.202953'
 }
 
 project(':mcp') {
@@ -1316,12 +1318,18 @@ def getArtifacts(project, config, classifiers) {
 }
 
 def checkExists(url) {
-    def code = new URL(url).openConnection().with {
-        requestMethod = 'HEAD'
-        connect()
-        responseCode
+    try {
+        def code = new URL(url).openConnection().with {
+            requestMethod = 'HEAD'
+            connect()
+            responseCode
+        }
+        return code == 200
+    } catch (Exception e) {
+        if (e.toString().contains('unable to find valid certification path to requested target'))
+            throw new RuntimeException('Failed to connect to ' + url + ': Missing certificate root authority, try updating java')
+        throw e
     }
-    return code == 200
 }
 
 def getClasspath(project, libs, artifact) {

gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-bin.zip

src/test/java/net/minecraftforge/debug/gameplay/loot/GlobalLootModifiersTest.java

@@ -25,7 +25,7 @@ import net.minecraft.world.storage.loot.LootParameterSets;
 import net.minecraft.world.storage.loot.LootParameters;
 import net.minecraft.world.storage.loot.LootTable;
 import net.minecraft.world.storage.loot.conditions.ILootCondition;
-import net.minecraftforge.common.loot.IGlobalLootModifierSerializer;
+import net.minecraftforge.common.loot.GlobalLootModifierSerializer;
 import net.minecraftforge.common.loot.LootModifier;
 import net.minecraftforge.event.RegistryEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
@@ -53,7 +53,7 @@ public class GlobalLootModifiersTest {
         }
 
         @SubscribeEvent
-        public static void registerModifierSerializers(@Nonnull final RegistryEvent.Register<IGlobalLootModifierSerializer<?>> event) {
+        public static void registerModifierSerializers(@Nonnull final RegistryEvent.Register<GlobalLootModifierSerializer<?>> event) {
             if (ENABLE) {
                 event.getRegistry().register(
                         new WheatSeedsConverterModifier.Serializer().setRegistryName(new ResourceLocation(MODID,"wheat_harvest"))
@@ -95,7 +95,7 @@ public class GlobalLootModifiersTest {
                     .orElse(stack);
         }
 
-        private static class Serializer extends LootModifier.Serializer<SmeltingEnchantmentModifier> {
+        private static class Serializer extends GlobalLootModifierSerializer<SmeltingEnchantmentModifier> {
             @Override
             public SmeltingEnchantmentModifier read(ResourceLocation name, JsonObject json, ILootCondition[] conditionsIn) {
                 return new SmeltingEnchantmentModifier(conditionsIn);
@@ -127,7 +127,7 @@ public class GlobalLootModifiersTest {
             return loottable.generate(ctx);
         }
 
-        private static class Serializer extends LootModifier.Serializer<SilkTouchTestModifier> {
+        private static class Serializer extends GlobalLootModifierSerializer<SilkTouchTestModifier> {
             @Override
             public SilkTouchTestModifier read(ResourceLocation name, JsonObject json, ILootCondition[] conditionsIn) {
                 return new SilkTouchTestModifier(conditionsIn);
@@ -137,7 +137,7 @@ public class GlobalLootModifiersTest {
 
     /**
      * When harvesting wheat with shears, this modifier is invoked via the wheat_harvest loot_modifier json<br/>
-     * This modifier checks how many seeds were harvested and turns X seeds into Y wheat (3:1)  
+     * This modifier checks how many seeds were harvested and turns X seeds into Y wheat (3:1)
      *
      */
     private static class WheatSeedsConverterModifier extends LootModifier {
@@ -173,7 +173,7 @@ public class GlobalLootModifiersTest {
             return generatedLoot;
         }
 
-        private static class Serializer extends LootModifier.Serializer<WheatSeedsConverterModifier> {
+        private static class Serializer extends GlobalLootModifierSerializer<WheatSeedsConverterModifier> {
 
             @Override
             public WheatSeedsConverterModifier read(ResourceLocation name, JsonObject object, ILootCondition[] conditionsIn) {