Reference : Remove child edits from m_plugEdits

Previously, we were only removing edit entries for the immediate
children of a Reference. This could leave stale edits in the edit
cache for plugs at the grandchild level and deeper. Usually that does
not cause a problem because `m_plugEdits` is keyed using the plug
pointer address. But on Windows in particular, the address of a
destroyed plug was occasionally (something like 1 in 1000) being reused
for a new plug, causing a false positive lookup in `m_plugEdits`.

Changes.md

@@ -19,6 +19,7 @@ Fixes
 - Windows :
   - Fixed a bug preventing anything except strings from being copied and pasted.
   - Fixed likely cause of crash when resizing Spreadsheet column width (#5296).
+- Reference : Fixed rare reloading error.
 
 1.3.5.0 (relative to 1.3.4.0)
 =======

src/Gaffer/Reference.cpp

@@ -395,6 +395,11 @@ class Reference::PlugEdits : public Signals::Trackable
 				return;
 			}
 
+			for( Plug::RecursiveIterator it( plug ); !it.done(); ++it )
+			{
+				m_plugEdits.erase( it->get() );
+			}
+
 			m_plugEdits.erase( plug );
 		}