tdf115103: find data source if sDataSource/sCommand are empty

In several functions data source was only found if sDataSource and
sCommand corresponded to what was set in fields.
In imported DOC(X) files these aren't set.

Now use the data source even if field's sDataSource/sCommand are
empty (similarly to SwDBManager::IsDataSourceOpen(...)).

Change-Id: I9563cb56e700e7fd033100cb200f41f074669020
Reviewed-on: https://gerrit.libreoffice.org/48285Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Aron Budea <aron.budea@collabora.com>

sw/source/uibase/dbui/dbmgr.cxx

@@ -1696,7 +1696,8 @@ sal_uLong SwDBManager::GetColumnFormat( const OUString& rDBName,
         uno::Reference< sdbcx::XColumnsSupplier> xColsSupp;
         bool bDisposeConnection = false;
         if(pImpl->pMergeData &&
-            pImpl->pMergeData->sDataSource == rDBName && pImpl->pMergeData->sCommand == rTableName)
+            ((pImpl->pMergeData->sDataSource == rDBName && pImpl->pMergeData->sCommand == rTableName) ||
+            (rDBName.isEmpty() && rTableName.isEmpty())))
         {
             xConnection = pImpl->pMergeData->xConnection;
             xSource = SwDBManager::getDataSourceAsParent(xConnection,rDBName);
@@ -2400,11 +2401,15 @@ sal_uInt32      SwDBManager::GetSelectedRecordId(
 {
     sal_uInt32 nRet = 0xffffffff;
     //check for merge data source first
-    if(pImpl->pMergeData && rDataSource == pImpl->pMergeData->sDataSource &&
-                    rTableOrQuery == pImpl->pMergeData->sCommand &&
-                    (nCommandType == -1 || nCommandType == pImpl->pMergeData->nCommandType) &&
-                    pImpl->pMergeData->xResultSet.is())
+    if(pImpl->pMergeData &&
+        ((rDataSource == pImpl->pMergeData->sDataSource &&
+        rTableOrQuery == pImpl->pMergeData->sCommand) ||
+        (rDataSource.isEmpty() && rTableOrQuery.isEmpty())) &&
+        (nCommandType == -1 || nCommandType == pImpl->pMergeData->nCommandType) &&
+        pImpl->pMergeData->xResultSet.is())
+    {
         nRet = GetSelectedRecordId();
+    }
     else
     {
         SwDBData aData;
@@ -2460,8 +2465,10 @@ void    SwDBManager::CloseAll(bool bIncludingMerge)
 SwDSParam* SwDBManager::FindDSData(const SwDBData& rData, bool bCreate)
 {
     //prefer merge data if available
-    if(pImpl->pMergeData && rData.sDataSource == pImpl->pMergeData->sDataSource &&
-        rData.sCommand == pImpl->pMergeData->sCommand &&
+    if(pImpl->pMergeData &&
+        ((rData.sDataSource == pImpl->pMergeData->sDataSource &&
+        rData.sCommand == pImpl->pMergeData->sCommand) ||
+        (rData.sDataSource.isEmpty() && rData.sCommand.isEmpty())) &&
         (rData.nCommandType == -1 || rData.nCommandType == pImpl->pMergeData->nCommandType ||
         (bCreate && pImpl->pMergeData->nCommandType == -1)))
     {