From a44ac7d29b2ec033b60383a7be2706c5349da71b Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Mon, 16 Feb 2026 09:52:56 -0800
Subject: [PATCH] Fix COMMIT::Stage assertion when CHT_DONE set on CHT_MODIFY

When undoLevelItem() remaps a child item to its parent, the change type
is forced to CHT_MODIFY but the CHT_DONE flag from the original
CHT_ADD/CHT_REMOVE was left intact. CHT_DONE means the original
add/remove was already applied to the child, but that semantic doesn't
carry over when we remap to a modify of the parent.

Strip CHT_DONE at the remapping site instead of as a general catch-all.
Keep the assertion as defense-in-depth for any future code path that
might combine CHT_MODIFY with CHT_DONE directly.

Fixes KICAD-102A
---
 common/commit.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/common/commit.cpp b/common/commit.cpp
index 2d0e7871fe..722440e394 100644
--- a/common/commit.cpp
+++ b/common/commit.cpp
@@ -50,11 +50,15 @@ COMMIT& COMMIT::Stage( EDA_ITEM* aItem, CHANGE_TYPE aChangeType, BASE_SCREEN* aS
     EDA_ITEM* undoItem = undoLevelItem( aItem );
 
     if( undoItem != aItem )
+    {
         changeType = CHT_MODIFY;
 
-    // CHT_MODIFY and CHT_DONE are not compatible
-    if( changeType == CHT_MODIFY )
-        wxASSERT( ( flags & CHT_DONE ) == 0 );
+        // CHT_DONE means the original add/remove was already applied to the child, but that
+        // semantic doesn't carry over when we remap to a modify of the parent
+        flags &= ~CHT_DONE;
+    }
+
+    wxASSERT( changeType != CHT_MODIFY || ( flags & CHT_DONE ) == 0 );
 
     switch( changeType )
     {