fdo#52451: Ensure that the extension for text is .txt from writer.

Added a preferred extension property to the filter which overwrites
one(s) given by the default file format type associated with it.

Normally this property is not used for the majority of the filters,
but for plain text filters, we need to use .txt when saving from
writer whereas we do .csv from calc.

Change-Id: I3453ad084e4379e5cc1101daeb9d2c3ddd919e92

filter/source/config/cache/constant.hxx

@@ -69,6 +69,7 @@
 #define  PROPNAME_USERDATA          "UserData"
 #define  PROPNAME_TEMPLATENAME      "TemplateName"
 #define  PROPNAME_FILEFORMATVERSION "FileFormatVersion"
+#define  PROPNAME_FILESAVEEXTENSION "FileSaveExtension"
 
 /** @short  used to identify a frame loader or detect service item
             property against the configuration API and can be used

filter/source/config/cache/filtercache.cxx

@@ -1834,6 +1834,7 @@ CacheItem FilterCache::impl_loadItem(const css::uno::Reference< css::container::
                 aItem[PROPNAME_UICOMPONENT      ] = xItem->getByName(PROPNAME_UICOMPONENT      );
                 aItem[PROPNAME_FILTERSERVICE    ] = xItem->getByName(PROPNAME_FILTERSERVICE    );
                 aItem[PROPNAME_DOCUMENTSERVICE  ] = xItem->getByName(PROPNAME_DOCUMENTSERVICE  );
+                aItem[PROPNAME_FILESAVEEXTENSION] = xItem->getByName(PROPNAME_FILESAVEEXTENSION);
 
                 // special handling for flags! Convert it from a list of names to its
                 // int representation ...

filter/source/config/fragments/filters/Text.xcu

@@ -4,6 +4,7 @@
         <prop oor:name="FilterService"/>
         <prop oor:name="UserData"><value>TEXT</value></prop>
         <prop oor:name="FileFormatVersion"><value>0</value></prop>
+        <prop oor:name="FileSaveExtension"><value>*.txt</value></prop>
         <prop oor:name="Type"><value>generic_Text</value></prop>
         <prop oor:name="TemplateName"/>
         <prop oor:name="DocumentService"><value>com.sun.star.text.TextDocument</value></prop>

filter/source/config/fragments/filters/Text___txt___csv__StarCalc_.xcu

@@ -4,6 +4,7 @@
         <prop oor:name="FilterService"/>
         <prop oor:name="UserData"><value></value></prop>
         <prop oor:name="FileFormatVersion"><value>0</value></prop>
+        <prop oor:name="FileSaveExtension"><value>*.csv</value></prop>
         <prop oor:name="Type"><value>generic_Text</value></prop>
         <prop oor:name="TemplateName"/>
         <prop oor:name="DocumentService"><value>com.sun.star.sheet.SpreadsheetDocument</value></prop>

filter/source/config/fragments/filters/Text__encoded_.xcu

@@ -4,6 +4,7 @@
         <prop oor:name="FilterService"/>
         <prop oor:name="UserData"><value>TEXT_DLG</value></prop>
         <prop oor:name="FileFormatVersion"><value>0</value></prop>
+        <prop oor:name="FileSaveExtension"><value>*.txt</value></prop>
         <prop oor:name="Type"><value>generic_Text</value></prop>
         <prop oor:name="TemplateName"/>
         <prop oor:name="DocumentService"><value>com.sun.star.text.TextDocument</value></prop>

officecfg/registry/schema/org/openoffice/TypeDetection/Filter.xcs

@@ -68,6 +68,9 @@
             </prop>
             <prop oor:name="UIName" oor:localized="true" oor:type="xs:string">
                 <info><desc>Localized name of the filter, whch can be shown at the UI.</desc></info>
+            </prop>
+            <prop oor:name="FileSaveExtension" oor:type="xs:string" oor:nillable="true">
+                <info><desc>Extension to use when exporting content using this filter.  When this value is not given, it is inferred from the Type associated with this filter.</desc></info>
             </prop>
 		</group>
 	</templates>

sfx2/source/bastyp/fltfnc.cxx

@@ -979,6 +979,12 @@ void SfxFilterContainer::ReadSingleFilter_Impl(
             {
                 lFilterProperties[nFilterProperty].Value >>= sServiceName;
             }
+            else if (lFilterProperties[nFilterProperty].Name == "FileSaveExtension")
+            {
+                // Extension preferred by the filter.  This takes precedence
+                // over those that are given in the file format type.
+                lFilterProperties[nFilterProperty].Value >>= sExtension;
+            }
             else if ( lFilterProperties[nFilterProperty].Name == "Type" )
             {
                 lFilterProperties[nFilterProperty].Value >>= sType;
@@ -1015,9 +1021,12 @@ void SfxFilterContainer::ReadSingleFilter_Impl(
                         }
                         else if ( lTypeProperties[nTypeProperty].Name == "Extensions" )
                         {
-                            ::com::sun::star::uno::Sequence< ::rtl::OUString > lExtensions;
-                            lTypeProperties[nTypeProperty].Value >>= lExtensions;
-                            sExtension = implc_convertStringlistToString( lExtensions, ';', DEFINE_CONST_UNICODE("*.") );
+                            if (sExtension.isEmpty())
+                            {
+                                ::com::sun::star::uno::Sequence< ::rtl::OUString > lExtensions;
+                                lTypeProperties[nTypeProperty].Value >>= lExtensions;
+                                sExtension = implc_convertStringlistToString( lExtensions, ';', DEFINE_CONST_UNICODE("*.") );
+                            }
                         }
                         else if ( lTypeProperties[nTypeProperty].Name == "URLPattern" )
                         {