[FIX] web_editor: properly set _powerboxBeforeStepIndex

Before this commit, `beforeStepIndex` (now `_powerboxBeforeStepIndex`),
was set at the wrong time.

The callback `onOpen` was called after opening the powerbox from the
`_onInput`. The calculation of `beforeStepIndex` presuposed the step
that add `/` happened. Thefore the calculation
`this._historySteps.length - 2` was made rather than
`this._historySteps.length - 1`.
But that presuposition is wrong.

The best time to know until which step index to revert is before any
possible step occurs.

task-2980550

closes odoo/odoo#100009

Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/static/src/js/editor/odoo-editor/src/OdooEditor.js

@@ -409,7 +409,6 @@ export class OdooEditor extends EventTarget {
         // Powerbox
         // --------
 
-        let beforeStepIndex;
         this.powerbox = new Powerbox({
             editable: this.editable,
             getContextFromParentRect: this.options.getContextFromParentRect,
@@ -417,13 +416,9 @@ export class OdooEditor extends EventTarget {
             onShow: () => {
                 this.powerboxTablePicker.hide();
             },
-            onOpen: () => {
-                // Undo input '/'.
-                beforeStepIndex = this._historySteps.length - 2;
-            },
             beforeCommand: () => {
                 if (this._isPowerboxOpenOnInput) {
-                    this._historyRevertUntil(beforeStepIndex);
+                    this._historyRevertUntil(this._powerboxBeforeStepIndex);
                     this.historyStep(true);
                     this._historyStepsStates.set(peek(this._historySteps).id, 'consumed');
                     setTimeout(() => {
@@ -2822,6 +2817,10 @@ export class OdooEditor extends EventTarget {
         const shouldOpenPowerbox = newSelection.isCollapsed && newSelection.rangeCount &&
             ev.data === '/' && this.powerbox && !this.powerbox.isOpen &&
             (!this.options.getPowerboxElement || !!this.options.getPowerboxElement());
+        if (shouldOpenPowerbox) {
+            // Undo input '/'.
+            this._powerboxBeforeStepIndex = this._historySteps.length - 1;
+        }
         // Record the selection position that was computed on keydown or before
         // contentEditable execCommand (whatever preceded the 'input' event)
         this._recordHistorySelection(true);

addons/web_editor/static/src/js/editor/odoo-editor/src/powerbox/Powerbox.js

@@ -26,14 +26,13 @@ function cycle(num, max) {
 export class Powerbox {
     constructor({
         categories, commands, commandFilters, editable, getContextFromParentRect,
-        onOpen, onShow, onStop, beforeCommand, afterCommand
+        onShow, onStop, beforeCommand, afterCommand
     } = {}) {
         this.categories = categories;
         this.commands = commands;
         this.commandFilters = commandFilters || [];
         this.editable = editable;
         this.getContextFromParentRect = getContextFromParentRect;
-        this.onOpen = onOpen;
         this.onShow = onShow;
         this.onStop = onStop;
         this.beforeCommand = beforeCommand;
@@ -102,9 +101,6 @@ export class Powerbox {
             priority: category.priority || 0,
         }));
         const order = (a, b) => b.priority - a.priority || a.name.localeCompare(b.name);
-        if (this.onOpen) {
-            this.onOpen();
-        }
         // Remove duplicate category names, keeping only last declared version,
         // and order them.
         categories = [...categories].reverse().filter((category, index, cats) => (