optimize ScHTMLExport::WriteTables() with large columns

Again, unless given a hint, mdds always starts a search from the beginning
of the container, so iterating over a column becomes quadratic.
Shows when selecting (the title of) a large column with different value types,
e.g. in tdf#120558, which triggers setting the selection from
VclQt5Clipboard::setContents(), which calls this.

Change-Id: Ida009c5ddf18ccdc8dff88c15530cc7e33ce80e7
Reviewed-on: https://gerrit.libreoffice.org/72366
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/sc/source/core/data/cellvalue.cxx b/sc/source/core/data/cellvalue.cxx
index 7fffc669ee6c..ef662c4818f7 100644
--- a/sc/source/core/data/cellvalue.cxx
+++ b/sc/source/core/data/cellvalue.cxx
@@ -567,6 +567,11 @@ ScRefCellValue::ScRefCellValue( ScDocument& rDoc, const ScAddress& rPos )
     assign( rDoc, rPos);
 }
 
+ScRefCellValue::ScRefCellValue( ScDocument& rDoc, const ScAddress& rPos, sc::ColumnBlockPosition& rBlockPos )
+{
+    assign( rDoc, rPos, rBlockPos );
+}
+
 void ScRefCellValue::clear()
 {
     // Reset to empty value.
@@ -579,6 +584,11 @@ void ScRefCellValue::assign( ScDocument& rDoc, const ScAddress& rPos )
     *this = rDoc.GetRefCellValue(rPos);
 }
 
+void ScRefCellValue::assign( ScDocument& rDoc, const ScAddress& rPos, sc::ColumnBlockPosition& rBlockPos )
+{
+    *this = rDoc.GetRefCellValue(rPos, rBlockPos);
+}
+
 void ScRefCellValue::commit( ScDocument& rDoc, const ScAddress& rPos ) const
 {
     switch (meType)