drop unused SvTreeListBoxFlags::IS_EXPANDING

Change-Id: I60ecf3b157cad3ebc58b6349690eccc0fedbd26a
Reviewed-on: https://gerrit.libreoffice.org/63482
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/unusedenumconstants.writeonly.results

@@ -2726,8 +2726,6 @@ include/svtools/treelistbox.hxx:191
     enum SvTreeListBoxFlags IN_EDT
 include/svtools/treelistbox.hxx:192
     enum SvTreeListBoxFlags EDT_ENABLED
-include/svtools/treelistbox.hxx:193
-    enum SvTreeListBoxFlags IS_EXPANDING
 include/svtools/treelistbox.hxx:194
     enum SvTreeListBoxFlags IS_TRAVELSELECT
 include/svtools/treelistbox.hxx:195

include/vcl/treelistbox.hxx

@@ -180,14 +180,13 @@ enum class SvTreeListBoxFlags
     NONE             = 0x0000,
     IN_EDT           = 0x0001,
     EDT_ENABLED      = 0x0002,
-    IS_EXPANDING     = 0x0004,
-    IS_TRAVELSELECT  = 0x0008,
-    TARGEMPH_VIS     = 0x0010,
-    EDTEND_CALLED    = 0x0020,
+    IS_TRAVELSELECT  = 0x0004,
+    TARGEMPH_VIS     = 0x0008,
+    EDTEND_CALLED    = 0x0010,
 };
 namespace o3tl
 {
-    template<> struct typed_flags<SvTreeListBoxFlags> : is_typed_flags<SvTreeListBoxFlags, 0x003f> {};
+    template<> struct typed_flags<SvTreeListBoxFlags> : is_typed_flags<SvTreeListBoxFlags, 0x001f> {};
 }
 
 struct SvTreeListBoxImpl;

vcl/source/treelist/treelistbox.cxx

@@ -2143,7 +2143,6 @@ bool SvTreeListBox::Expand( SvTreeListEntry* pParent )
         RequestingChildren( pParent );
     if( pParent->HasChildren() )
     {
-        nImpFlags |= SvTreeListBoxFlags::IS_EXPANDING;
         if( ExpandingHdl() )
         {
             bExpanded = true;
@@ -2177,7 +2176,6 @@ bool SvTreeListBox::Expand( SvTreeListEntry* pParent )
 
 bool SvTreeListBox::Collapse( SvTreeListEntry* pParent )
 {
-    nImpFlags &= ~SvTreeListBoxFlags::IS_EXPANDING;
     pHdlEntry = pParent;
     bool bCollapsed = false;