execute the terrible bottle neck loop only if there are conditional formats

Change-Id: Ic8bd65a728289c9fa1a0721b0ecbd9b4a48672ca
(cherry picked from commit 2aefb89b)
Reviewed-on: https://gerrit.libreoffice.org/16902Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

sc/inc/conditio.hxx

@@ -495,6 +495,7 @@ public:
     const_iterator end() const;
 
     size_t size() const;
+    bool empty() const;
 
     void erase(sal_uLong nIndex);
 

sc/source/core/data/conditio.cxx

@@ -2321,6 +2321,11 @@ size_t ScConditionalFormatList::size() const
     return maConditionalFormats.size();
 }
 
+bool ScConditionalFormatList::empty() const
+{
+    return maConditionalFormats.empty();
+}
+
 void ScConditionalFormatList::erase( sal_uLong nIndex )
 {
     for( iterator itr = begin(); itr != end(); ++itr )

sc/source/core/data/documen7.cxx

@@ -141,8 +141,11 @@ void ScDocument::BroadcastCells( const ScRange& rRange, sal_uLong nHint, bool bB
             continue;
 
         ScConditionalFormatList* pCondFormList = GetCondFormList(nTab);
-        if (pCondFormList)
+        if (pCondFormList && !pCondFormList->empty())
         {
+            /* TODO: looping over all possible cells is a terrible bottle neck,
+             * for each cell looping over all conditional formats even worse,
+             * this certainly needs a better method. */
             ScAddress aAddress( 0, 0, nTab);
             for (SCROW nRow = nRow1; nRow <= nRow2; ++nRow)
             {