[Junie]: fix(codegen): set group delimiter for deeply nested components

quickfixj-codegenerator/src/main/resources/org/quickfixj/codegenerator/MessageSubclass.xsl

@@ -205,6 +205,15 @@ import quickfix.Group;</xsl:if>
 	</xsl:if>
 </xsl:template>
 
+<!-- New: ensure recursion continues inside component definitions (no group ancestor needed) -->
+<xsl:template mode="group-delimeter" match="component">
+	<xsl:if test="position() = 1">
+		<xsl:variable name="name" select="@name"/>
+		<xsl:apply-templates select="/fix/components/component[@name=$name]/*[name(.)='field' or name(.)='group' or name(.)='component']"
+			mode="group-delimeter"/>
+	</xsl:if>
+</xsl:template>
+
   <!-- Find the component numbers and order -->
 
 <xsl:template mode="component-field-numbers" match="field">

quickfixj-codegenerator/src/test/java/org/quickfixj/codegenerator/NestedGroupDelimiterTest.java

@@ -0,0 +1,74 @@
+package org.quickfixj.codegenerator;
+
+import static org.junit.Assert.*;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Verifies that the code generator sets the correct group delimiter when the
+ * first element of a repeating group is a component that nests other components
+ * before the first concrete field appears.
+ *
+ * This covers the regression fixed in PR #1089 where the XSL must recurse into
+ * deeply nested components to locate the actual first field (delimiter).
+ */
+public class NestedGroupDelimiterTest {
+
+    private final File outputDirectory = new File("./target/test-output/");
+    private final File dictFile = new File("./src/test/resources/NESTED_FIX.xml");
+    private final File schemaDirectory = new File("./src/main/resources/org/quickfixj/codegenerator");
+
+    @Before
+    public void setup() throws IOException {
+        if (outputDirectory.exists()) {
+            FileUtils.cleanDirectory(outputDirectory);
+        } else {
+            outputDirectory.mkdirs();
+        }
+    }
+
+    @Test
+    public void generatesGroupWithDeeplyNestedDelimiter() throws Exception {
+        MessageCodeGenerator generator = new MessageCodeGenerator();
+        MessageCodeGenerator.Task task = new MessageCodeGenerator.Task();
+
+        task.setSpecification(dictFile);
+        task.setName(dictFile.getName());
+        task.setTransformDirectory(schemaDirectory);
+        task.setMessagePackage("quickfix.fixZZ");
+        task.setOutputBaseDirectory(outputDirectory);
+        task.setFieldPackage("quickfix.field");
+        task.setUtcTimestampPrecision(null);
+        task.setOverwrite(true);
+        task.setOrderedFields(true);
+        task.setDecimalGenerated(true);
+
+        try {
+            generator.generate(task);
+        } catch (CodeGenerationException e) {
+            // Surface with context for easier debugging in CI
+            throw new AssertionError("Code generation failed: " + e.getMessage(), e);
+        }
+
+        // Read the generated message class and assert the group constructor uses FieldA (1001) as delimiter
+        File generated = new File(outputDirectory, "quickfix/fixZZ/NestedGroupTest.java");
+        assertTrue("Expected generated message class not found: " + generated.getAbsolutePath(), generated.exists());
+
+        String java = FileUtils.readFileToString(generated, StandardCharsets.UTF_8);
+
+        // The group name is NoOuterGrp with counter tag 1000. The delimiter should be FieldA (1001),
+        // which is the first field reachable by recursing into components (InnerComponent -> DeepComponent -> FieldA)
+        // The generated constructor should therefore look like: super(1000, 1001, ORDER)
+        assertTrue(
+            "Group constructor should use 1001 as delimiter for NoOuterGrp (deeply nested first field)",
+            java.contains("public static class NoOuterGrp") &&
+            java.contains("super(1000, 1001, ORDER)")
+        );
+    }
+}

quickfixj-codegenerator/src/test/resources/NESTED_FIX.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<fix major="4" type="FIX" minor="4">
+  <header>
+  </header>
+  <messages>
+    <message name="NestedGroupTest" msgtype="ZZ" msgcat="app">
+      <group name="NoOuterGrp" required="N">
+        <component name="InnerComponent" required="N"/>
+      </group>
+    </message>
+  </messages>
+  <components>
+    <component name="InnerComponent">
+      <component name="DeepComponent"/>
+    </component>
+    <component name="DeepComponent">
+      <!-- The first concrete field deep inside the component tree -->
+      <field name="FieldA" required="N"/>
+      <field name="FieldB" required="N"/>
+    </component>
+  </components>
+  <fields>
+    <!-- Group counter field -->
+    <field number="1000" name="NoOuterGrp" type="NUMINGROUP"/>
+    <!-- Deepest first field that should become the group delimiter -->
+    <field number="1001" name="FieldA" type="STRING"/>
+    <field number="1002" name="FieldB" type="STRING"/>
+  </fields>
+  <trailer>
+  </trailer>
+</fix>