From c16808c38024f04f0a401adf84dd0c9cf03daed0 Mon Sep 17 00:00:00 2001
From: Artur Wieczorek <artwik@wp.pl>
Date: Fri, 11 Jul 2014 17:01:28 +0000
Subject: [PATCH] Adjust list of items for deferred deletion/removal if wxPG
 property item is actually deleted/removed.

When property is actually deleted/removed it must be also removed from the respective list of items for deferred deletion/removal in order to avoid crashes when it would be attempted to delete/remove it again at next wxPG idle state.
Because lists of items for deferred operations can be updated at every actual deletion/removal it is necessary to rearrange iteration through these lists in wxPG::OnIdle.

See #16222.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76889 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 src/propgrid/propgrid.cpp          | 42 ++++++++++++++++++++----------
 src/propgrid/propgridpagestate.cpp | 31 ++++++++++++++++++++++
 2 files changed, 59 insertions(+), 14 deletions(-)

diff --git a/src/propgrid/propgrid.cpp b/src/propgrid/propgrid.cpp
index dc1e1b2837..2dc4688772 100644
--- a/src/propgrid/propgrid.cpp
+++ b/src/propgrid/propgrid.cpp
@@ -5798,23 +5798,37 @@ void wxPropertyGrid::OnIdle( wxIdleEvent& WXUNUSED(event) )
 
     //
     // Resolve pending property removals
-    if ( m_deletedProperties.size() > 0 )
+    // In order to determine whether deletion/removal
+    // was done we need to track the size of the list
+    // before and after the operation.
+    // (Note that lists are changed at every operation.)
+    size_t cntAfter = m_deletedProperties.size();
+    while ( cntAfter > 0 )
     {
-        wxArrayPGProperty& arr = m_deletedProperties;
-        for ( unsigned int i=0; i<arr.size(); i++ )
-        {
-            DeleteProperty(arr[i]);
-        }
-        arr.clear();
+        size_t cntBefore = cntAfter;
+
+        DeleteProperty(m_deletedProperties[0]);
+
+        cntAfter = m_deletedProperties.size();
+        wxASSERT_MSG( cntAfter <= cntBefore,
+            wxT("Increased number of pending items after deletion") );
+        // Break if deletion was not done
+        if ( cntAfter >= cntBefore )
+            break;
     }
-    if ( m_removedProperties.size() > 0 )
+    cntAfter = m_removedProperties.size();
+    while ( cntAfter > 0 )
     {
-        wxArrayPGProperty& arr = m_removedProperties;
-        for ( unsigned int i=0; i<arr.size(); i++ )
-        {
-            RemoveProperty(arr[i]);
-        }
-        arr.clear();
+        size_t cntBefore = cntAfter;
+
+        RemoveProperty(m_removedProperties[0]);
+
+        cntAfter = m_removedProperties.size();
+        wxASSERT_MSG( cntAfter <= cntBefore,
+            wxT("Increased number of pending items after removal") );
+        // Break if removal was not done
+        if ( cntAfter >= cntBefore )
+            break;
     }
 }
 
diff --git a/src/propgrid/propgridpagestate.cpp b/src/propgrid/propgridpagestate.cpp
index c5f5789a29..4c8f482fa8 100644
--- a/src/propgrid/propgridpagestate.cpp
+++ b/src/propgrid/propgridpagestate.cpp
@@ -1964,9 +1964,40 @@ void wxPropertyGridPageState::DoDelete( wxPGProperty* item, bool doDelete )
 
     // We can actually delete it now
     if ( doDelete )
+    {
+        // Remove the item from both lists of pending operations.
+        // (Deleted item cannot be also the subject of further removal.)
+        int index = pg->m_deletedProperties.Index(item);
+        if ( index != wxNOT_FOUND )
+        {
+            pg->m_deletedProperties.RemoveAt(index);
+        }
+        wxASSERT_MSG( pg->m_deletedProperties.Index(item) == wxNOT_FOUND,
+                    wxT("Too many occurences of the item"));
+
+        index = pg->m_removedProperties.Index(item);
+        if ( index != wxNOT_FOUND )
+        {
+            pg->m_removedProperties.RemoveAt(index);
+        }
+        wxASSERT_MSG( pg->m_removedProperties.Index(item) == wxNOT_FOUND,
+                    wxT("Too many occurences of the item"));
+
         delete item;
+    }
     else
+    {
+        // Remove the item from the list of pending removals.
+        int index = pg->m_removedProperties.Index(item);
+        if ( index != wxNOT_FOUND )
+        {
+            pg->m_removedProperties.RemoveAt(index);
+        }
+        wxASSERT_MSG( pg->m_removedProperties.Index(item) == wxNOT_FOUND,
+                    wxT("Too many occurences of the item"));
+
         item->OnDetached(this, pg);
+    }
 
     m_itemsAdded = 1; // Not a logical assignment (but required nonetheless).