test: non-shallow copy of OverrideCLISetValues in DeepCopy + test

Signed-off-by: Vojta Polak <vojta.polak@gmail.com>

pkg/app/load_opts.go

@@ -30,7 +30,17 @@ func (o LoadOpts) DeepCopy() LoadOpts {
 		panic(err)
 	}
 
-	new.Environment.OverrideCLISetValues = o.Environment.OverrideCLISetValues
+	if src := o.Environment.OverrideCLISetValues; src != nil {
+		b, err := yaml.Marshal(src)
+		if err != nil {
+			panic(err)
+		}
+		var dst []any
+		if err := yaml.Unmarshal(b, &dst); err != nil {
+			panic(err)
+		}
+		new.Environment.OverrideCLISetValues = dst
+	}
 
 	return new
 }

pkg/app/load_opts_test.go

@@ -34,3 +34,20 @@ func TestLoadOptsDeepCopyPreservesOverrideCLISetValues(t *testing.T) {
 
 	require.Equal(t, lOld.Environment.OverrideCLISetValues, lNew.Environment.OverrideCLISetValues, "DeepCopy should preserve OverrideCLISetValues field")
 }
+
+// TestLoadOptsDeepCopyOverrideCLISetValuesIsNotShallow verifies that mutating a
+// map nested inside OverrideCLISetValues on the copy does not affect the
+// original.
+func TestLoadOptsDeepCopyOverrideCLISetValuesIsNotShallow(t *testing.T) {
+	lOld := LoadOpts{}
+	lOld.Environment.OverrideCLISetValues = []any{map[string]any{"key": "original"}}
+
+	lNew := lOld.DeepCopy()
+
+	// Mutate the map inside the copy.
+	lNew.Environment.OverrideCLISetValues[0].(map[string]any)["key"] = "mutated"
+
+	// The original must be unaffected; this fails with a shallow copy.
+	require.Equal(t, "original", lOld.Environment.OverrideCLISetValues[0].(map[string]any)["key"],
+		"mutating the copy's OverrideCLISetValues map must not affect the original (aliasing bug)")
+}