From 826a25c7d1896414721f4ff8d1ce57795ad5e030 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aur=C3=A9lien=20Warnon?= <awa@odoo.com>
Date: Fri, 20 Mar 2020 10:58:01 +0000
Subject: [PATCH] [FIX] survey: fix back button behavior

This commit fixes 2 small problems when the user goes back on the survey form:

- The back button should not be shown on "page_per_question" layout if we are
  on the first page of the survey.
  Pages can be displayed on "page_per_question" layout if they have a
  description since #44271
- Can't go back on "page_per_section" layout if you are on the second page of
  the survey, introduced by 0675d68afb7afe69e5e9d62a172c273a6d0b83e8

LINKS

PR #48442
Task 2208574
---
 addons/survey/models/survey_survey.py    |  2 +-
 addons/survey/views/survey_templates.xml | 11 +++++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/addons/survey/models/survey_survey.py b/addons/survey/models/survey_survey.py
index da8e1670fad..94d3a5bece6 100644
--- a/addons/survey/models/survey_survey.py
+++ b/addons/survey/models/survey_survey.py
@@ -481,7 +481,7 @@ class Survey(models.Model):
         current_page_index = pages_or_questions.ids.index(next(p.id for p in pages_or_questions if p.id == page_or_question_id))
 
         # Get previous and we are on first page  OR Get Next and we are on last page
-        if (go_back and current_page_index == 0) or current_page_index == len(pages_or_questions) - 1:
+        if (go_back and current_page_index == 0) or (not go_back and current_page_index == len(pages_or_questions) - 1):
             return Question
 
         # Conditional Questions Management
diff --git a/addons/survey/views/survey_templates.xml b/addons/survey/views/survey_templates.xml
index 4cc54cca006..b8addaaab7f 100644
--- a/addons/survey/views/survey_templates.xml
+++ b/addons/survey/views/survey_templates.xml
@@ -202,8 +202,15 @@
 
                 <div class="row">
                     <div class="offset-3 col-6 text-center mt16 mb128">
-                        <button t-if="not answer.is_session_answer and survey.users_can_go_back and question != answer.predefined_question_ids[0]" type="submit" class="btn btn-secondary"
-                                name="button_submit" value="previous" t-att-data-previous-page-id="previous_page_id">Back</button>
+                        <!-- Can go back if:
+                            - Back button is allowed in configuration
+                            - This is not a session answer (doesn't make sense to go back in session context)
+                            - This is not the first question
+                            - The survey doesn't have pages OR this is not the first page of the survey
+                              (pages are displayed in 'page_per_question' layout when they have a description, see PR#44271)
+                        -->
+                        <button t-if="survey.users_can_go_back and not answer.is_session_answer and question != answer.predefined_question_ids[0] and (not survey.page_ids or question != survey.page_ids[0])"
+                            type="submit" class="btn btn-secondary" name="button_submit" value="previous" t-att-data-previous-page-id="previous_page_id">Back</button>
                         <button type="submit" t-att-value="'next' if not survey_last else 'finish'" class="btn btn-primary">
                             <t t-if="answer.is_session_answer">
                                 Submit