From b825c49c2eab4662c45466741e5da1b81c9a6c4c Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sat, 15 Dec 2018 22:49:33 +0100
Subject: [PATCH] Document and test wxItemContainer::Delete() selection
 handling

Add test checking that selection is reset when deleting the selected
item or any item before, but not after, it.

Also explicitly document this behaviour.
---
 interface/wx/ctrlsub.h               |  6 ++++++
 tests/controls/itemcontainertest.cpp | 27 +++++++++++++++++++++++++++
 tests/controls/itemcontainertest.h   |  2 ++
 3 files changed, 35 insertions(+)

diff --git a/interface/wx/ctrlsub.h b/interface/wx/ctrlsub.h
index 3e1d8d0da6..a9582e7b10 100644
--- a/interface/wx/ctrlsub.h
+++ b/interface/wx/ctrlsub.h
@@ -354,6 +354,12 @@ public:
         failure in debug builds) to remove an item with the index negative or
         greater or equal than the number of items in the control.
 
+        If there is a currently selected item below the item being deleted,
+        i.e. if GetSelection() returns a valid index greater than or equal to
+        @a n, the selection is invalidated when this function is called.
+        However if the selected item appears before the item being deleted, the
+        selection is preserved unchanged.
+
         @param n
             The zero-based item index.
 
diff --git a/tests/controls/itemcontainertest.cpp b/tests/controls/itemcontainertest.cpp
index 874e926794..ffc49d0197 100644
--- a/tests/controls/itemcontainertest.cpp
+++ b/tests/controls/itemcontainertest.cpp
@@ -270,6 +270,33 @@ void ItemContainerTestCase::SetString()
 #endif
 }
 
+void ItemContainerTestCase::SelectionAfterDelete()
+{
+    wxItemContainer * const container = GetContainer();
+
+    container->Append("item 0");
+    container->Append("item 1");
+    container->Append("item 2");
+    container->Append("item 3");
+
+    container->SetSelection(1);
+    CHECK( container->GetSelection() == 1 );
+
+    container->Delete(3);
+    CHECK( container->GetSelection() == 1 );
+
+    container->Delete(1);
+    CHECK( container->GetSelection() == wxNOT_FOUND );
+
+    container->SetSelection(1);
+    container->Delete(1);
+    CHECK( container->GetSelection() == wxNOT_FOUND );
+
+    container->SetSelection(0);
+    container->Delete(0);
+    CHECK( container->GetSelection() == wxNOT_FOUND );
+}
+
 void ItemContainerTestCase::SetSelection()
 {
     wxItemContainer * const container = GetContainer();
diff --git a/tests/controls/itemcontainertest.h b/tests/controls/itemcontainertest.h
index 63923d25e8..49ca3fdcab 100644
--- a/tests/controls/itemcontainertest.h
+++ b/tests/controls/itemcontainertest.h
@@ -40,6 +40,7 @@ protected:
         CPPUNIT_TEST( Set ); \
         CPPUNIT_TEST( SetSelection ); \
         CPPUNIT_TEST( SetString ); \
+        CPPUNIT_TEST( SelectionAfterDelete ); \
         WXUISIM_TEST( SimSelect );
 
     void Append();
@@ -52,6 +53,7 @@ protected:
     void Set();
     void SetSelection();
     void SetString();
+    void SelectionAfterDelete();
 #if wxUSE_UIACTIONSIMULATOR
     virtual void SimSelect();
 #endif