Suppress overlapping detected climbs when official claims are unsorted

2 files changed, 25 insertions, 2 deletions

diff --git a/ride/climb.go b/ride/climb.go
index f42a9a2..647cf9a 100644
--- a/ride/climb.go
+++ b/ride/climb.go
@@ -270,12 +270,17 @@ func isValidClaim(claim Range, routeLen int) bool {
 // freeRegions returns the maximal sub-ranges of [rStart, rEnd] that are not
 // covered by any claimed range, after discarding claims that fall outside.
 func freeRegions(rStart, rEnd int, claimed []Range) []Range {
-	regions := make([]Range, 0, len(claimed)+1)
-	current := rStart
+	valid := make([]Range, 0, len(claimed))
 	for _, claim := range claimed {
 		if !isValidClaim(claim, rEnd+1) {
 			continue
 		}
+		valid = append(valid, claim)
+	}
+	slices.SortFunc(valid, func(a, b Range) int { return a.Start - b.Start })
+	regions := make([]Range, 0, len(valid)+1)
+	current := rStart
+	for _, claim := range valid {
 		if claim.End < current {
 			continue
 		}
diff --git a/ride/climb_test.go b/ride/climb_test.go
index c0d4bd6..6b5c097 100644
--- a/ride/climb_test.go
+++ b/ride/climb_test.go
@@ -169,3 +169,21 @@ func TestDetectClimbsIgnoresOutOfRangeClaim(t *testing.T) {
 	require.Len(t, climbs, 1)
 	assert.Equal(t, "0.0km-2.0km: 2.0km at 7.0% (98 pts - Cat 3)", climbs[0].String())
 }
+
+func TestDetectClimbsWithUnsortedClaimsDropsOverlappingClimb(t *testing.T) {
+	// Reproduces ride 6 Chemin des Lauriers bug: DetectClimbs must not depend on
+	// caller-provided order. Two official claims out of ID order (Bastides
+	// 2140-2627 before Lauriers 1215-1588) caused freeRegions to skip the
+	// earlier claim and leave the overlapping Cat 4 1352-1601 visible.
+	// Minimal reproduction: two climbs 0-2km and 3-5km separated by a descent.
+	r := RideBuilder{precision: 100}.WithSection("2km at 7%").WithSection("1km at -7%").WithSection("2km at 7%").Build()
+	// Both climbs claimed, but in reverse order (mimics ORDER BY id returning 30-50 before 0-20).
+	// Sorted input correctly yields 0 detected climbs.
+	sorted := []ride.Range{{Start: 0, End: 20}, {Start: 30, End: 50}}
+	assert.Empty(t, r.DetectClimbs(sorted, ride.ClimbSlopeMinimum))
+
+	unsorted := []ride.Range{{Start: 30, End: 50}, {Start: 0, End: 20}}
+	climbs := r.DetectClimbs(unsorted, ride.ClimbSlopeMinimum)
+	// Before fix this fails: freeRegions skips {0,20} because 20 < 30 and returns 1 climb.
+	assert.Empty(t, climbs, "unsorted claimed ranges must still suppress overlapping climbs — expected 0, got %v", climbs)
+}