partial fix

front/src/applications/operationalStudies/hooks/useSetupItineraryForTrainUpdate.ts

@@ -162,6 +162,7 @@ const useSetupItineraryForTrainUpdate = (
           rolling_stock_length: rollingStock.length,
         },
       };
+      console.log('call useSetup');
       const pathfindingResult = await postPathfindingBlocks(params).unwrap();
       if (pathfindingResult.status !== 'success') {
         return null;

front/src/modules/pathfinding/hooks/usePathfinding.ts

@@ -1,4 +1,4 @@
-import { useState, useEffect, useReducer } from 'react';
+import { useState, useEffect, useReducer, useRef } from 'react';
 
 import { compact, isEqual, isObject } from 'lodash';
 import { useTranslation } from 'react-i18next';
@@ -28,6 +28,7 @@ import type { PathStep } from 'reducers/osrdconf/types';
 import { useAppDispatch } from 'store';
 import { isEmptyArray } from 'utils/array';
 import { castErrorToFailure } from 'utils/error';
+import { usePrevious } from 'utils/hooks/state';
 
 import useInfraStatus from './useInfraStatus';
 
@@ -113,6 +114,7 @@ export function reducer(state: PathfindingState, action: PathfindingAction): Pat
       return {
         ...state,
         error: '',
+        done: false,
         mustBeLaunched: true,
         missingParam: false,
       };
@@ -156,6 +158,7 @@ export const usePathfinding = (
   const origin = useSelector(getOrigin, isEqual);
   const destination = useSelector(getDestination, isEqual);
   const vias = useSelector(getVias(), isEqual);
+  const previousVias = usePrevious(vias);
   const pathSteps = useSelector(getPathSteps);
   const powerRestrictions = useSelector(getPowerRestriction);
   const { infra, reloadCount, setIsInfraError } = useInfraStatus();
@@ -196,7 +199,27 @@ export const usePathfinding = (
   };
 
   useEffect(() => {
-    if (isPathfindingInitialized) {
+    // check if vias changes are only discrepancies at 5th+ decimal places
+    // pathfindingState.done is true right after pathfinding completes
+    // it becomes false once we change any parameter
+    // we can safely assume previousVias and vias have the same length and that the order is preserved
+    let skipDispatch = false;
+    if (pathfindingState.done && previousVias && previousVias.length === vias.length) {
+      skipDispatch = previousVias?.every(
+        (pVia, i) =>
+          console.log(
+            vias,
+            previousVias,
+            pVia.coordinates,
+            vias[i].coordinates,
+            pVia.coordinates[0] - vias[i].coordinates[0],
+            pVia.coordinates[1] - vias[i].coordinates[1]
+          ) ||
+          (Math.abs(pVia.coordinates[0] - vias[i].coordinates[0]) <= 0.00001 &&
+            Math.abs(pVia.coordinates[1] - vias[i].coordinates[1]) <= 0.00001)
+      );
+    }
+    if (isPathfindingInitialized && !skipDispatch) {
       pathfindingDispatch({
         type: 'VIAS_CHANGED',
         params: {