Fix safe-outputs body:null parsing to enable field updates

pkg/workflow/data/action_pins.json

@@ -65,6 +65,11 @@
       "version": "v4.3.1",
       "sha": "67a3573c9a986a3f9c594539f4ab511d57bb3ce9"
     },
+    "actions/setup-go@v5": {
+      "repo": "actions/setup-go",
+      "version": "v5",
+      "sha": "40f1582b2485089dde7abd97c1529aa768e1baff"
+    },
     "actions/setup-go@v6.2.0": {
       "repo": "actions/setup-go",
       "version": "v6.2.0",

pkg/workflow/update_entity_helpers.go

@@ -40,12 +40,18 @@
 //     body: null     # Can update body (key exists)
 //     ```
 //
-//  2. **Bool Value Mode** (for pull requests):
-//     Fields are enabled based on explicit boolean values:
+//  2. **Bool Value Mode** (for body/footer fields in all entities):
+//     Fields are enabled based on explicit boolean values.
+//     Special case: null values are treated as true for backward compatibility:
 //     ```yaml
+//     update-issue:
+//       body: true     # Explicitly enable body updates
+//       body: false    # Explicitly disable body updates
+//       body: null     # Treated as true (backward compatibility)
+//       body:          # Same as null, treated as true
 //     update-pull-request:
-//     title: true    # Can update title
-//     body: false    # Cannot update body
+//       title: true    # Can update title
+//       body: false    # Cannot update body
 //     ```
 //
 // # When to Use vs Alternatives
@@ -194,8 +200,9 @@ const (
 	// FieldParsingKeyExistence mode: Field presence (even if nil) indicates it can be updated
 	// Used by update-issue and update-discussion
 	FieldParsingKeyExistence FieldParsingMode = iota
-	// FieldParsingBoolValue mode: Field's boolean value determines if it can be updated
-	// Used by update-pull-request (defaults to true if nil)
+	// FieldParsingBoolValue mode: Field's boolean value determines if it can be updated.
+	// Special case: nil values are treated as true for backward compatibility.
+	// Used by body/footer fields in all update entities.
 	FieldParsingBoolValue
 )
 
@@ -212,7 +219,9 @@ const (
 //
 // Behavior by mode:
 //   - FieldParsingKeyExistence: Returns new(bool) if key exists, nil otherwise
-//   - FieldParsingBoolValue: Returns &boolValue if key exists and is bool, nil otherwise
+//   - FieldParsingBoolValue: Returns &boolValue if key exists and is bool.
+//     Special case: if key exists with nil value (e.g., body: null), returns &true
+//     for backward compatibility. Returns nil for other non-bool values (invalid config).
 func parseUpdateEntityBoolField(configMap map[string]any, fieldName string, mode FieldParsingMode) *bool {
 	if configMap == nil {
 		return nil
@@ -233,7 +242,13 @@ func parseUpdateEntityBoolField(configMap map[string]any, fieldName string, mode
 		if boolVal, ok := val.(bool); ok {
 			return &boolVal
 		}
-		// If present but not a bool (e.g., null), return nil (no explicit setting)
+		// If value is explicitly nil (not a bool), treat as true (explicit enablement)
+		// This maintains backward compatibility where body: null enables the field
+		if val == nil {
+			trueVal := true
+			return &trueVal
+		}
+		// For other non-bool values (like strings), return nil (invalid config)
 		return nil
 
 	default:

pkg/workflow/update_entity_helpers_test.go

@@ -78,7 +78,8 @@ func TestParseUpdateEntityBoolField(t *testing.T) {
 			configMap: map[string]any{"title": nil},
 			fieldName: "title",
 			mode:      FieldParsingBoolValue,
-			wantNil:   true, // Non-bool values return nil
+			wantNil:   false, // Nil values are treated as true (explicit enablement)
+			wantValue: true,  // Defaults to true for backward compatibility
 		},
 		{
 			name:      "bool value mode: string value (not a bool)",

pkg/workflow/update_issue_test.go

@@ -360,10 +360,13 @@ This workflow tests body: (null) for backward compatibility.
 		t.Fatal("Expected update-issue configuration to be parsed")
 	}
 
-	// With FieldParsingBoolValue mode, null values result in nil pointer
-	// The handler will default to true via AddBoolPtrOrDefault
+	// With FieldParsingBoolValue mode, null values are treated as true (explicit enablement)
 	// This maintains backward compatibility where body: enables body updates
-	if workflowData.SafeOutputs.UpdateIssues.Body != nil {
-		t.Fatal("Expected body to be nil when set to null (will default to true in handler)")
+	if workflowData.SafeOutputs.UpdateIssues.Body == nil {
+		t.Fatal("Expected body to be non-nil when set to null")
+	}
+
+	if !*workflowData.SafeOutputs.UpdateIssues.Body {
+		t.Fatal("Expected body to be true when set to null (backward compatibility)")
 	}
 }