tdf#147861 ww8import: solve TODO: not fixed-field if equal

Do not mark the field as "fixed" if the displayed string
matches the internal variable. This allows changing the variable
within LO and having the field update to reflect that change,
which is the way that these fields are supposed to work
(although in MS Word they only update manually via F9
 which is why some needed to be fixed in the first place).

Change-Id: Id359cbf0b48e63bddab3e45871326988467d7ddb
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/131414
Tested-by: Jenkins
Reviewed-by: Justin Luth <jluth@mail.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

1 files changed, 20 insertions, 3 deletions

diff --git a/sw/source/filter/ww8/ww8par5.cxx b/sw/source/filter/ww8/ww8par5.cxx
index 66b08888416b..a78fa37f2e45 100644
--- a/sw/source/filter/ww8/ww8par5.cxx
+++ b/sw/source/filter/ww8/ww8par5.cxx
@@ -1650,13 +1650,30 @@ eF_ResT SwWW8ImplReader::Read_F_DocInfo( WW8FieldDesc* pF, OUString& rStr )
             // In other words, Word lets the field to be out of sync with the controlling variable.
             // Marking as FIXEDFLD solves the automatic replacement problem, but of course prevents
             // Writer from making any changes, even on an F9 refresh.
-            // TODO: If the field already matches the DocProperty, no need to mark as fixed.
             // TODO: Extend LO to allow a linked field that doesn't automatically update.
+            IDocumentContentOperations& rIDCO(m_rDoc.getIDocumentContentOperations());
             const auto pType(static_cast<SwDocInfoFieldType*>(
                 m_rDoc.getIDocumentFieldsAccess().GetSysFieldType(SwFieldIds::DocInfo)));
             const OUString sDisplayed = GetFieldResult(pF);
-            SwDocInfoField aField(pType, DI_CUSTOM | DI_SUB_FIXED | nReg, aDocProperty, sDisplayed);
-            m_rDoc.getIDocumentContentOperations().InsertPoolItem(*m_pPaM, SwFormatField(aField));
+            SwDocInfoField aField(pType, DI_CUSTOM | nReg, aDocProperty);
+
+            // If text already matches the DocProperty var, then safe to treat as refreshable field.
+            OUString sVariable = aField.ExpandField(/*bCache=*/false, nullptr);
+            if (sDisplayed.getLength() != sVariable.getLength())
+            {
+                sal_Int32 nLen = sVariable.indexOf('\x0');
+                if (nLen >= 0)
+                    sVariable = sVariable.copy(0, nLen);
+            }
+            if (sDisplayed == sVariable)
+                rIDCO.InsertPoolItem(*m_pPaM, SwFormatField(aField));
+            else
+            {
+                // They don't match, so use a fixed field to prevent LO from altering the contents.
+                SwDocInfoField aFixedField(pType, DI_CUSTOM | DI_SUB_FIXED | nReg, aDocProperty,
+                                           sDisplayed);
+                rIDCO.InsertPoolItem(*m_pPaM, SwFormatField(aFixedField));
+            }
 
             return eF_ResT::OK;
         }