From f2b542972ff71b636582e5d03b84b9134bd9e639 Mon Sep 17 00:00:00 2001
From: Mathieu DEHARBE <mathieu.deharbe@rte-france.com>
Date: Tue, 24 Mar 2026 14:43:22 +0100
Subject: [PATCH 1/2] tapPosition used to an index and is now a key

Signed-off-by: Mathieu DEHARBE <mathieu.deharbe@rte-france.com>
---
 .../tooltips/branch/twt-tap-changer-characteristics.tsx       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx b/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
index 0b5683ba6f..51ec6b8926 100644
--- a/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
+++ b/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
@@ -25,7 +25,7 @@ export const TwtTapChangerCharacteristics: React.FC<TwtTapChangerCharacteristics
     if (ratioTapChanger) {
         rows.push({
             tap: ratioTapChanger.tapPosition,
-            rho: ratioTapChanger.steps[ratioTapChanger.tapPosition - ratioTapChanger.lowTapPosition].rho,
+            rho: ratioTapChanger.tapPosition ? ratioTapChanger.steps[ratioTapChanger.tapPosition].rho : '-',
             alpha: '-',
             mode: getComputedRegulationMode(equipmentInfos)?.label,
         });
@@ -35,7 +35,7 @@ export const TwtTapChangerCharacteristics: React.FC<TwtTapChangerCharacteristics
         rows.push({
             tap: phaseTapChanger.tapPosition ?? '-',
             rho: '-',
-            alpha: phaseTapChanger.steps[phaseTapChanger.tapPosition - phaseTapChanger.lowTapPosition].alpha,
+            alpha: phaseTapChanger.tapPosition ? phaseTapChanger.steps[phaseTapChanger.tapPosition].alpha : '-',
             mode: getComputedPhaseTapChangerRegulationMode(phaseTapChanger)?.label,
         });
     }

From ed565ac5ff7052fc9c5192d08473b0bf068ae830 Mon Sep 17 00:00:00 2001
From: Mathieu DEHARBE <mathieu.deharbe@rte-france.com>
Date: Tue, 24 Mar 2026 14:53:46 +0100
Subject: [PATCH 2/2] remove not that good security

Signed-off-by: Mathieu DEHARBE <mathieu.deharbe@rte-france.com>
---
 .../tooltips/branch/twt-tap-changer-characteristics.tsx       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx b/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
index 51ec6b8926..06ad367d0b 100644
--- a/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
+++ b/src/components/tooltips/branch/twt-tap-changer-characteristics.tsx
@@ -25,7 +25,7 @@ export const TwtTapChangerCharacteristics: React.FC<TwtTapChangerCharacteristics
     if (ratioTapChanger) {
         rows.push({
             tap: ratioTapChanger.tapPosition,
-            rho: ratioTapChanger.tapPosition ? ratioTapChanger.steps[ratioTapChanger.tapPosition].rho : '-',
+            rho: ratioTapChanger.steps[ratioTapChanger.tapPosition].rho,
             alpha: '-',
             mode: getComputedRegulationMode(equipmentInfos)?.label,
         });
@@ -35,7 +35,7 @@ export const TwtTapChangerCharacteristics: React.FC<TwtTapChangerCharacteristics
         rows.push({
             tap: phaseTapChanger.tapPosition ?? '-',
             rho: '-',
-            alpha: phaseTapChanger.tapPosition ? phaseTapChanger.steps[phaseTapChanger.tapPosition].alpha : '-',
+            alpha: phaseTapChanger.steps[phaseTapChanger.tapPosition].alpha,
             mode: getComputedPhaseTapChangerRegulationMode(phaseTapChanger)?.label,
         });
     }