Fix nil pointer error when using skip_obsolete with list keys

gogen/codegen_test.go

@@ -1123,6 +1123,20 @@ func TestSimpleStructs(t *testing.T) {
 			},
 		},
 		wantStructsCodeFile: filepath.Join(TestRoot, "testdata/structs/presence-container-example.formatted-txt"),
+	}, {
+		name:    "skip obsolete list keys test",
+		inFiles: []string{filepath.Join(datapath, "skip-obsolete-test.yang")},
+		inConfig: CodeGenerator{
+			IROptions: ygen.IROptions{
+				TransformationOptions: ygen.TransformationOpts{
+					SkipObsolete: true,
+				},
+			},
+			GoOptions: GoOpts{
+				GenerateSimpleUnions: true,
+			},
+		},
+		wantErrSubstring: "did not find type for key obsolete-key",
 	}}
 
 	for _, tt := range tests {

gogen/unordered_list.go

@@ -546,7 +546,10 @@ func generateGetListKey(buf *bytes.Buffer, s *ygen.ParsedDirectory, nameMap map[
 	sort.Strings(kn)
 
 	for _, k := range kn {
-		h.Keys = append(h.Keys, nameMap[k])
+		// Skip keys that don't exist in nameMap (e.g., when skip_obsolete is enabled)
+		if fieldMap, ok := nameMap[k]; ok {
+			h.Keys = append(h.Keys, fieldMap)
+		}
 	}
 
 	return goKeyMapTemplate.Execute(buf, h)

testdata/modules/skip-obsolete-test.yang

@@ -0,0 +1,29 @@
+module skip-obsolete-test {
+  prefix "sot";
+  namespace "urn:sot";
+
+  container top {
+    list interfaces {
+      key "name obsolete-key";
+
+      leaf name {
+        type string;
+        description "Interface name";
+      }
+
+      leaf obsolete-key {
+        type string;
+        status obsolete;
+        description "Obsolete key that should be skipped";
+      }
+
+      leaf admin-status {
+        type enumeration {
+          enum up;
+          enum down;
+        }
+        description "Administrative status";
+      }
+    }
+  }
+}