fdo#53929: Pivot table uses case insensitive string comparison.

Change-Id: I65fa22ceeba37a15b70fe41b1dee26f1dde7d759

sc/source/core/data/dpcache.cxx

@@ -195,7 +195,7 @@ struct EqualByValue : std::binary_function<Bucket, Bucket, bool>
 {
     bool operator() (const Bucket& left, const Bucket& right) const
     {
-        return left.maValue == right.maValue;
+        return left.maValue.IsCaseInsEqual(right.maValue);
     }
 };
 
@@ -251,7 +251,7 @@ void processBuckets(std::vector<Bucket>& aBuckets, ScDPCache::Field& rField)
         it->mnOrderIndex = nCurIndex;
         for (++it; it != itEnd; ++it)
         {
-            if (aPrev != it->maValue)
+            if (!aPrev.IsCaseInsEqual(it->maValue))
                 ++nCurIndex;
 
             it->mnOrderIndex = nCurIndex;

sc/source/core/data/dpitemdata.cxx

@@ -210,8 +210,9 @@ bool ScDPItemData::IsCaseInsEqual(const ScDPItemData& r) const
             ;
     }
 
-    if (mbStringInterned && r.mbStringInterned)
-        return mpString == r.mpString;
+    if (mbStringInterned && r.mbStringInterned && mpString == r.mpString)
+        // Fast equality check for interned strings.
+        return true;
 
     return ScGlobal::GetpTransliteration()->isEqual(GetString(), r.GetString());
 }