Sync with integration

core/dr-pipeline/src/sidecar.rs

@@ -1088,7 +1088,7 @@ impl std::error::Error for ParseError {}
 mod tests {
     use super::*;
     use crate::framing;
-    use crate::ops::{exposure, saturation, white_balance};
+    use crate::ops::{curve, exposure, saturation, white_balance};
 
     fn edited() -> EditGraph {
         let mut g = EditGraph::default_chain();
@@ -1273,6 +1273,90 @@ mod tests {
         assert_eq!(once, twice);
     }
 
+    /// TRACES: FR-DEV-3 | FR-CAT-8
+    /// A file written before the tone curve had per-channel curves.
+    ///
+    /// Spelled out as literal text rather than produced by `to_text`, because
+    /// the claim is about *those bytes*: a sidecar generated by this build
+    /// would agree with this build by construction, and would go on agreeing
+    /// with it through a rename that broke every file on disk.
+    #[test]
+    fn a_sidecar_from_before_the_channel_curves_still_names_the_master() {
+        let text = "drsc 1\n\n[version u1]\nname = Default\nrevision = 4\nmodified = 9\n\
+                    tone_curve.p1_y = 0.15\ntone_curve.p3_y = 0.85\n";
+        let parsed = Sidecar::parse(text).expect("valid");
+        let mut g = EditGraph::default_chain();
+        parsed.default_version().expect("a version").apply(&mut g);
+
+        // The S-curve the file describes, on the master curve and nowhere
+        // else.
+        assert_eq!(g.param(curve::ID, curve::P1_Y), Some(0.15));
+        assert_eq!(g.param(curve::ID, curve::P3_Y), Some(0.85));
+        for channel in [curve::Channel::Red, curve::Channel::Green, curve::Channel::Blue] {
+            for point in 0..curve::POINTS {
+                for axis in [curve::Axis::X, curve::Axis::Y] {
+                    let id = curve::coordinate(channel, point, axis);
+                    let expected = g
+                        .capabilities()
+                        .iter()
+                        .find(|c| c.id == curve::ID)
+                        .and_then(|c| c.params.iter().find(|p| p.id == id))
+                        .map(|p| p.default);
+                    assert_eq!(
+                        g.param(curve::ID, id),
+                        expected,
+                        "{id} moved, and no line in the file mentions it"
+                    );
+                }
+            }
+        }
+
+        // And writing it back produces the same two lines: the curves the file
+        // never mentioned are still at their defaults, so they are still
+        // absent (`only_non_default_values_are_written`).
+        let written = Sidecar::parse(&Sidecar::parse(text).expect("valid").to_text())
+            .expect("valid")
+            .to_text();
+        assert!(written.contains("tone_curve.p1_y = 0.15"), "{written}");
+        assert!(written.contains("tone_curve.p3_y = 0.85"), "{written}");
+        assert!(
+            !written.contains("tone_curve.r_"),
+            "an untouched channel curve was written out:\n{written}"
+        );
+    }
+
+    /// TRACES: FR-DEV-3
+    /// The other direction: the new curves persist like any other parameter.
+    #[test]
+    fn a_per_channel_curve_survives_the_round_trip() {
+        let mut g = EditGraph::default_chain();
+        // A faded shadow: blue lifted at the black point, red pulled down.
+        let blue = curve::coordinate(curve::Channel::Blue, 0, curve::Axis::Y);
+        let red = curve::coordinate(curve::Channel::Red, 4, curve::Axis::Y);
+        g.set_param(curve::ID, blue, 0.08);
+        g.set_param(curve::ID, red, 0.92);
+        g.set_param(curve::ID, curve::P2_Y, 0.55);
+
+        let mut sidecar = Sidecar::new();
+        sidecar.put(version_of(&g));
+        let text = sidecar.to_text();
+        // Keyed by the channel-prefixed id, which is what makes the master's
+        // unprefixed ones safe to leave alone.
+        assert!(text.contains("tone_curve.b_p0_y = 0.08"), "{text}");
+
+        let parsed = Sidecar::parse(&text).expect("valid");
+        let mut restored = EditGraph::default_chain();
+        parsed
+            .default_version()
+            .expect("a version")
+            .apply(&mut restored);
+
+        assert_eq!(restored.param(curve::ID, blue), Some(0.08));
+        assert_eq!(restored.param(curve::ID, red), Some(0.92));
+        assert_eq!(restored.param(curve::ID, curve::P2_Y), Some(0.55));
+        assert!(!restored.is_neutral());
+    }
+
     #[test]
     fn an_unknown_operation_survives_a_round_trip() {
         // The data-loss case that matters: a device running an older build