Function TEST

pj_plotting/tests/plot_widget_range_offset_test.cpp:98–111

With "Use time offset" ON, the axis frames display window [0, 1] s. Saving must record the ABSOLUTE window [1.6e9, 1.6e9 + 1] s. The layout always stores a time axis absolute (the offset is a visualization concern), so NO x_absolute marker is written — the plot mode distinguishes time-series from XY on load.

// axis absolute (the offset is a visualization concern), so NO x_absolute marker is
// written — the plot mode distinguishes time-series from XY on load.
TEST(PlotWidgetRangeOffset, SavesAbsoluteTimeRange) {
  PlotFixture fixture;
  fixture.session.setUseTimeOffset(true);  // display offset = dataset min = kT0Ns
  fixture.plot.setZoomRectangle(QRectF(0.0, -5.0, 1.0, 10.0), /*emit_signal=*/false);

  QDomDocument doc;
  const QDomElement plot_element = fixture.plot.xmlSaveState(doc);
  const QDomElement range = plot_element.firstChildElement(QStringLiteral("range"));
  ASSERT_FALSE(range.isNull());

  EXPECT_FALSE(range.hasAttribute(QStringLiteral("x_absolute"))) << "the obsolete marker must not be written";
  EXPECT_NEAR(range.attribute(QStringLiteral("left")).toDouble(), kT0Sec, 1e-3);
  EXPECT_NEAR(range.attribute(QStringLiteral("right")).toDouble(), kT0Sec + 1.0, 1e-3);
}

// The core bug: save with the offset ON, load with it OFF. The restored axis
// must still frame the same ABSOLUTE instant. With the offset now 0, display ==