tdf#118441: also keep string-formula results for shared formulas

... like it is done for normal cells.
So, the cells that have markup like

        <row r="2" ...>
            <c r="A2" t="str">
                <f t="shared" ref="A2:A65" si="0">Test(B2:Z2)</f>
                <v>0</v>
            </c>
        </row>
        <row r="3" ...>
            <c r="A3" t="str">
                <f t="shared" si="0"/>
                <v>0</v>
            </c>
        </row>

now are handled (wrt restoring the stored result value) just like
cells with this markup without sharing have long been handled:

        <row r="1" ...>
            <c r="A1" t="str">
                <f>Test(B1:Z1)</f>
                <v>0</v>
            </c>
        </row>

Change-Id: Ifcf62cf6d073faff310aa8553c6f57f42ae588cc
Reviewed-on: https://gerrit.libreoffice.org/56675
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
(cherry picked from commit e6c43ed9)
Reviewed-on: https://gerrit.libreoffice.org/56732Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>

sc/source/filter/oox/formulabuffer.cxx

@@ -109,7 +109,8 @@ void applySharedFormulas(
     ScDocumentImport& rDoc,
     SvNumberFormatter& rFormatter,
     std::vector<FormulaBuffer::SharedFormulaEntry>& rSharedFormulas,
-    std::vector<FormulaBuffer::SharedFormulaDesc>& rCells )
+    std::vector<FormulaBuffer::SharedFormulaDesc>& rCells,
+    bool bGeneratorKnownGood)
 {
     sc::SharedFormulaGroups aGroups;
     {
@@ -132,6 +133,7 @@ void applySharedFormulas(
     }
 
     {
+        svl::SharedStringPool& rStrPool = rDoc.getDoc().GetSharedStringPool();
         // Process formulas that use shared formulas.
         for (const FormulaBuffer::SharedFormulaDesc& rDesc : rCells)
         {
@@ -149,7 +151,7 @@ void applySharedFormulas(
                 continue;
             }
 
-            // Set cached formula results. For now, we only use numeric
+            // Set cached formula results. For now, we only use numeric and string-formula
             // results. Find out how to utilize cached results of other types.
             switch (rDesc.mnValueType)
             {
@@ -157,6 +159,19 @@ void applySharedFormulas(
                     // numeric value.
                     pCell->SetResultDouble(rDesc.maCellValue.toDouble());
                 break;
+                case XML_str:
+                    if (bGeneratorKnownGood)
+                    {
+                        // See applyCellFormulaValues
+                        svl::SharedString aSS = rStrPool.intern(rDesc.maCellValue);
+                        pCell->SetResultToken(new formula::FormulaStringToken(aSS));
+                        // If we don't reset dirty, then e.g. disabling macros makes all cells
+                        // that use macro functions to show #VALUE!
+                        pCell->ResetDirty();
+                        pCell->SetChanged(false);
+                        break;
+                    }
+                    SAL_FALLTHROUGH;
                 default:
                     // Mark it for re-calculation.
                     pCell->SetDirty();
@@ -291,7 +306,8 @@ void processSheetFormulaCells(
     const Sequence<ExternalLinkInfo>& rExternalLinks, bool bGeneratorKnownGood )
 {
     if (rItem.mpSharedFormulaEntries && rItem.mpSharedFormulaIDs)
-        applySharedFormulas(rDoc, rFormatter, *rItem.mpSharedFormulaEntries, *rItem.mpSharedFormulaIDs);
+        applySharedFormulas(rDoc, rFormatter, *rItem.mpSharedFormulaEntries,
+                            *rItem.mpSharedFormulaIDs, bGeneratorKnownGood);
 
     if (rItem.mpCellFormulas)
     {