[FIX] web: stabilize sequence for new records on last page

Before this commit, the compute sequence was relying on the fact the ID was used
as a secondary order key to get the right result.

This is necessary when adding items between pages because we don't resequence
the following elements.

However this was not necessary when adding new elements on the last page since
there are no following elements to resesquence in that case.

PR: #27639

1 files changed, 7 insertions, 1 deletions

diff --git a/addons/web/static/src/js/views/basic/basic_model.js b/addons/web/static/src/js/views/basic/basic_model.js
index f6bf46aed68..0afb65a9a88 100644
--- a/addons/web/static/src/js/views/basic/basic_model.js
+++ b/addons/web/static/src/js/views/basic/basic_model.js
@@ -398,8 +398,14 @@ var BasicModel = AbstractModel.extend({
         // by 1 (at least until there is a gap in the numbering).
 
         // We don't do it now because it's not an important case.
+        // However, we can for sure increment by 1 if we are on the last page.
+
         var handleFieldValue = computedList.data[index].data[handleField];
-        handleFieldValue = position !== 'top' ? handleFieldValue : handleFieldValue - 1;
+        if (position === 'top') {
+            handleFieldValue--;
+        } else if (list.count <= list.offset + list.limit - (list.tempLimitIncrement || 0)) {
+            handleFieldValue++;
+        }
 
         return {
             field: handleField,