index is 1-based in this case

Change-Id: I74aae3f422423de09cb012e274f8d536f8b778f1

sc/source/core/data/colorscale.cxx

@@ -148,12 +148,13 @@ void ScColorScaleFormatList::AddFormat( ScColorScaleFormat* pFormat )
     maColorScaleFormats.push_back( pFormat );
 }
 
+// attention nFormat is 1 based, 0 is reserved for no format
 ScColorScaleFormat* ScColorScaleFormatList::GetFormat(sal_uInt32 nFormat)
 {
-    if( nFormat >= size() )
+    if( nFormat > size() || !nFormat )
         return NULL;
 
-    return &maColorScaleFormats[nFormat];
+    return &maColorScaleFormats[nFormat-1];
 }
 
 ScColorScaleFormatList::iterator ScColorScaleFormatList::begin()

sc/source/core/data/documen4.cxx

@@ -629,6 +629,7 @@ sal_uLong ScDocument::AddCondFormat( const ScConditionalFormat& rNew )
 }
 
 //takes ownership
+// returns a 1-based index, 0 is reserved for no entry
 sal_uLong ScDocument::AddColorScaleFormat( ScColorScaleFormat* pNew )
 {
     if(!pNew)
@@ -639,7 +640,7 @@ sal_uLong ScDocument::AddColorScaleFormat( ScColorScaleFormat* pNew )
 
     mpColorScaleList->AddFormat( pNew );
 
-    return mpColorScaleList->size()-1;
+    return mpColorScaleList->size();
 }
 
 sal_uLong ScDocument::AddValidationEntry( const ScValidationData& rNew )