Fix #1205

Author: modmuss50

src/main/java/net/fabricmc/loom/configuration/decompile/SplitDecompileConfiguration.java

@@ -79,12 +79,19 @@ public void afterEvaluation() {
 		for (DecompilerOptions options : extension.getDecompilerOptions()) {
 			final String decompilerName = options.getFormattedName();
 
+			var commonTask = project.getTasks().named("gen%sSourcesWith%s".formatted("Common", decompilerName));
+			var clientOnlyTask = project.getTasks().named("gen%sSourcesWith%s".formatted("ClientOnly", decompilerName));
+
+			clientOnlyTask.configure(task -> {
+				task.mustRunAfter(commonTask);
+			});
+
 			project.getTasks().register("genSourcesWith" + decompilerName, task -> {
 				task.setDescription("Decompile minecraft using %s.".formatted(decompilerName));
 				task.setGroup(Constants.TaskGroup.FABRIC);
 
-				task.dependsOn(project.getTasks().named("gen%sSourcesWith%s".formatted("Common", decompilerName)));
-				task.dependsOn(project.getTasks().named("gen%sSourcesWith%s".formatted("ClientOnly", decompilerName)));
+				task.dependsOn(commonTask);
+				task.dependsOn(clientOnlyTask);
 			});
 		}
 

src/test/groovy/net/fabricmc/loom/test/integration/SplitProjectTest.groovy

@@ -29,6 +29,7 @@ import spock.lang.Unroll
 
 import net.fabricmc.loom.test.util.GradleProjectTestTrait
 
+import static net.fabricmc.loom.test.LoomTestConstants.PRE_RELEASE_GRADLE
 import static net.fabricmc.loom.test.LoomTestConstants.STANDARD_TEST_VERSIONS
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
@@ -48,4 +49,16 @@ class SplitProjectTest extends Specification implements GradleProjectTestTrait {
 		where:
 		version << STANDARD_TEST_VERSIONS
 	}
+
+	@Unroll
+	def "genSources (gradle #version)"() {
+		setup:
+		def gradle = gradleProject(project: "splitSources", version: PRE_RELEASE_GRADLE)
+
+		when:
+		def result = gradle.run(tasks: ["genSources"])
+
+		then:
+		result.task(":genSources").outcome == SUCCESS
+	}
 }