Get a decomp workspace working without forge being loaded

plugin/src/main/java/com/gtnewhorizons/retrofuturagradle/mcp/MCPTasks.java

@@ -887,14 +887,19 @@ private void afterEvaluate() {
                     .configure(t -> t.onlyIf("skipping slow task", p -> !t.getOutputJar().get().getAsFile().exists()));
         }
 
-        deps.addProvider(
-                forgeUserdevConfiguration.getName(),
-                mcExt.getForgeVersion()
-                        .map(forgeVer -> String.format("net.minecraftforge:forge:%s:userdev", forgeVer)));
-        deps.addProvider(
-                forgeUniversalConfiguration.getName(),
-                mcExt.getForgeVersion()
-                        .map(forgeVer -> String.format("net.minecraftforge:forge:%s:universal", forgeVer)));
+        if (mcExt.getUsesForge().get()) {
+            deps.addProvider(
+                    forgeUserdevConfiguration.getName(),
+                    mcExt.getForgeVersion()
+                            .map(forgeVer -> String.format("net.minecraftforge:forge:%s:userdev", forgeVer)));
+        }
+
+        if (mcExt.getUsesForge().get()) {
+            deps.addProvider(
+                    forgeUniversalConfiguration.getName(),
+                    mcExt.getForgeVersion()
+                            .map(forgeVer -> String.format("net.minecraftforge:forge:%s:universal", forgeVer)));
+        }
 
         // Workaround https://github.com/gradle/gradle/issues/10861 to avoid publishing these dependencies
         for (String configName : new String[] { JavaPlugin.COMPILE_CLASSPATH_CONFIGURATION_NAME,
@@ -985,21 +990,24 @@ private void afterEvaluate() {
                 });
             }
         }
+
         if (mcExt.getUsesFml().get()) {
             deobfuscationATs.builtBy(taskExtractForgeUserdev);
             if (mcMinor <= 8) {
                 deobfuscationATs.from(userdevFile(Constants.PATH_USERDEV_FML_ACCESS_TRANFORMER));
             }
 
-            taskPatchDecompiledJar.configure(task -> {
-                task.getPatches().builtBy(taskExtractForgeUserdev);
-                task.getInjectionDirectories().builtBy(taskExtractForgeUserdev);
-                if (mcMinor <= 8) {
-                    task.getPatches().from(userdevFile("fmlpatches.zip"));
-                }
-                task.getInjectionDirectories().from(userdevDir("src/main/java"));
-                task.getInjectionDirectories().from(userdevDir("src/main/resources"));
-            });
+            if (!"1.12.2".equals(mcExt.getMcVersion().get()) || mcExt.getUsesForge().get()) {
+                taskPatchDecompiledJar.configure(task -> {
+                    task.getPatches().builtBy(taskExtractForgeUserdev);
+                    task.getInjectionDirectories().builtBy(taskExtractForgeUserdev);
+                    if (mcMinor <= 8) {
+                        task.getPatches().from(userdevFile("fmlpatches.zip"));
+                    }
+                    task.getInjectionDirectories().from(userdevDir("src/main/java"));
+                    task.getInjectionDirectories().from(userdevDir("src/main/resources"));
+                });
+            }
 
             final String mcVer = mcExt.getMcVersion().get();
             final String PATCHED_MC_CFG = patchedConfiguration.getName();

plugin/src/main/java/com/gtnewhorizons/retrofuturagradle/mcp/SharedMCPTasks.java

@@ -143,7 +143,7 @@ public SharedMCPTasks(Project project, McExtType mcExt, MinecraftTasks mcTasks)
         taskExtractForgeUserdev = project.getTasks().register("extractForgeUserdev", Copy.class, task -> {
             task.onlyIf(t -> {
                 final File root = userdevExtractRoot.get().getAsFile();
-                return !(root.isDirectory() && new File(root, "dev.json").isFile());
+                return !forgeUserdevConfiguration.isEmpty() && !(root.isDirectory() && new File(root, "dev.json").isFile());
             });
             task.getOutputs().upToDateWhen(t -> {
                 final File root = userdevExtractRoot.get().getAsFile();
@@ -153,7 +153,7 @@ public SharedMCPTasks(Project project, McExtType mcExt, MinecraftTasks mcTasks)
             task.from(
                     project.provider(
                             () -> project.zipTree(
-                                    forgeUserdevConfiguration.fileCollection(Specs.SATISFIES_ALL).getSingleFile())));
+                                    forgeUserdevConfiguration.fileCollection(Specs.SATISFIES_ALL))));
             task.into(userdevExtractRoot);
             task.doFirst("mkdir", new MkdirAction(userdevExtractRoot));
             task.doLast("extractFg2DataIfNeeded", tsk -> {

settings.gradle.kts

@@ -21,3 +21,4 @@ plugins {
 include("testmod")
 include("testmod1.12")
 include("testdepmod")
+include("testnoforgeenv")

testnoforgeenv/build.gradle.kts

@@ -0,0 +1,25 @@
+plugins {
+    id("com.gtnewhorizons.retrofuturagradle")
+}
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+}
+
+java {
+    toolchain {
+        languageVersion.set(JavaLanguageVersion.of(8))
+        vendor.set(JvmVendorSpec.AZUL)
+    }
+    withSourcesJar()
+    withJavadocJar()
+}
+
+minecraft {
+    mcVersion.set("1.12.2")
+    usesForge.set(false)
+}
+
+group = "testnoforgeenv"
+version = "1.0"