Resolves: tdf#94249 do not remove broadcasters while iterators are in use

EndListeningContext holds BroadcasterStoreType iterators in its
ColumnBlockPositionSet and collects broadcasters to purge them at the
end. Removing broadcasters from ScColumn::maBroadcasters in between
invalidates the iterators. Hence calling the "normal" EndListening()
that removes a broadcaster when all listeners are gone while an
EndListeningContext is in use is bad.

Change-Id: Ibdd88469e91e6173ceff1f391c23ef7cb7c6f596
(cherry picked from commit e4a8ae0b)
Reviewed-on: https://gerrit.libreoffice.org/18615Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sc/inc/sharedformula.hxx

@@ -64,8 +64,9 @@ public:
      * specified position is not a formula cell.
      *
      * @param aPos position of cell to examine.
+     * @param pCxt context to be used, if any, may be nullptr.
      */
-    static void splitFormulaCellGroup(const CellStoreType::position_type& aPos);
+    static void splitFormulaCellGroup(const CellStoreType::position_type& aPos, sc::EndListeningContext* pCxt);
 
     /**
      * Split existing shared formula ranges at specified row positions.

sc/source/core/data/column.cxx

@@ -1908,15 +1908,15 @@ void ScColumn::MoveTo(SCROW nStartRow, SCROW nEndRow, ScColumn& rCol)
 
     // Split the formula grouping at the top and bottom boundaries.
     sc::CellStoreType::position_type aPos = maCells.position(nStartRow);
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, nullptr);
     aPos = maCells.position(aPos.first, nEndRow+1);
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, nullptr);
 
     // Do the same with the destination column.
     aPos = rCol.maCells.position(nStartRow);
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, nullptr);
     aPos = rCol.maCells.position(aPos.first, nEndRow+1);
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, nullptr);
 
     // Move the broadcasters to the destination column.
     maBroadcasters.transfer(nStartRow, nEndRow, rCol.maBroadcasters, nStartRow);

sc/source/core/data/column3.cxx

@@ -327,13 +327,13 @@ void ScColumn::DetachFormulaCells(
     const sc::CellStoreType::position_type& aPos, size_t nLength )
 {
     // Split formula grouping at the top and bottom boundaries.
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, nullptr);
     size_t nRow = aPos.first->position + aPos.second;
     size_t nNextTopRow = nRow + nLength; // start row of next formula group.
     if (ValidRow(nNextTopRow))
     {
         sc::CellStoreType::position_type aPos2 = maCells.position(aPos.first, nNextTopRow);
-        sc::SharedFormulaUtil::splitFormulaCellGroup(aPos2);
+        sc::SharedFormulaUtil::splitFormulaCellGroup(aPos2, nullptr);
     }
 
     if (pDocument->IsClipOrUndo())
@@ -368,11 +368,11 @@ void ScColumn::DetachFormulaCells( sc::EndListeningContext& rCxt, SCROW nRow1, S
     sc::CellStoreType::iterator it = aPos.first;
 
     // Split formula grouping at the top and bottom boundaries.
-    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+    sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, &rCxt);
     if (ValidRow(nRow2+1))
     {
         aPos = maCells.position(it, nRow2+1);
-        sc::SharedFormulaUtil::splitFormulaCellGroup(aPos);
+        sc::SharedFormulaUtil::splitFormulaCellGroup(aPos, &rCxt);
     }
 
     if (pDocument->IsClipOrUndo())

sc/source/core/tool/sharedformula.cxx

@@ -16,7 +16,7 @@
 
 namespace sc {
 
-void SharedFormulaUtil::splitFormulaCellGroup(const CellStoreType::position_type& aPos)
+void SharedFormulaUtil::splitFormulaCellGroup(const CellStoreType::position_type& aPos, sc::EndListeningContext* pCxt)
 {
     SCROW nRow = aPos.first->position + aPos.second;
 
@@ -61,7 +61,14 @@ void SharedFormulaUtil::splitFormulaCellGroup(const CellStoreType::position_type
     // other listeners, all listeners of this group's top cell are to be reset.
     if (nLength2)
     {
-        rPrevTop.EndListeningTo( rPrevTop.GetDocument(), NULL, ScAddress( ScAddress::UNINITIALIZED));
+        // If a context exists it has to be used to not interfere with
+        // ScColumn::maBroadcasters iterators, which the EndListeningTo()
+        // without context would do when removing a broadcaster that had its
+        // last listener removed.
+        if (pCxt)
+            rPrevTop.EndListeningTo(*pCxt);
+        else
+            rPrevTop.EndListeningTo( rPrevTop.GetDocument(), NULL, ScAddress( ScAddress::UNINITIALIZED));
         rPrevTop.SetNeedsListening(true);
     }
 #endif
@@ -107,7 +114,7 @@ void SharedFormulaUtil::splitFormulaCellGroups(CellStoreType& rCells, std::vecto
     if (aPos.first == rCells.end())
         return;
 
-    splitFormulaCellGroup(aPos);
+    splitFormulaCellGroup(aPos, nullptr);
     std::vector<SCROW>::iterator itEnd = rBounds.end();
     for (++it; it != itEnd; ++it)
     {
@@ -116,7 +123,7 @@ void SharedFormulaUtil::splitFormulaCellGroups(CellStoreType& rCells, std::vecto
         if (aPos.first == rCells.end())
             return;
 
-        splitFormulaCellGroup(aPos);
+        splitFormulaCellGroup(aPos, nullptr);
     }
 }