tdf#103389: Resaving a DOCX document with two canvases leads to a broken file.

Make custom shape export more robust. In case of the test
document, WriteCustomGeometry is called, but this call
does not export anything, and so we get a shape without
any geometry in the DOCX file, which causes problem to MS Word.

Reviewed-on: https://gerrit.libreoffice.org/30241
Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>
Tested-by: Tamás Zolnai <tamas.zolnai@collabora.com>
(cherry picked from commit f7c61b08d526c79ecd1522dff79386059b6125e0)

Change-Id: Ie7a4e2b8a18bfddaeeb81425ae5f1de04140d43f

2 files changed, 11 insertions, 8 deletions

diff --git a/oox/source/export/drawingml.cxx b/oox/source/export/drawingml.cxx
index 319b791f7cd4..b320eed12127 100644
--- a/oox/source/export/drawingml.cxx
+++ b/oox/source/export/drawingml.cxx
@@ -2216,23 +2216,23 @@ void DrawingML::WritePresetShape( const char* pShape, MSO_SPT eShapeType, bool b
     mpFS->endElementNS(  XML_a, XML_prstGeom );
 }
 
-void DrawingML::WriteCustomGeometry( Reference< XShape > rXShape )
+bool DrawingML::WriteCustomGeometry( Reference< XShape > rXShape )
 {
     uno::Reference< beans::XPropertySet > aXPropSet;
     uno::Any aAny( rXShape->queryInterface(cppu::UnoType<beans::XPropertySet>::get()));
 
     if ( ! (aAny >>= aXPropSet) )
-        return;
+        return false;
 
     try
     {
         aAny = aXPropSet->getPropertyValue( "CustomShapeGeometry" );
         if ( !aAny.hasValue() )
-            return;
+            return false;
     }
     catch( const ::uno::Exception& )
     {
-        return;
+        return false;
     }
 
 
@@ -2264,7 +2264,7 @@ void DrawingML::WriteCustomGeometry( Reference< XShape > rXShape )
                 }
 
                 if ( !aPairs.hasElements() )
-                    return;
+                    return false;
 
                 if ( !aSegments.hasElements() )
                 {
@@ -2288,7 +2288,7 @@ void DrawingML::WriteCustomGeometry( Reference< XShape > rXShape )
                 if ( nExpectedPairCount > aPairs.getLength() )
                 {
                     SAL_WARN("oox", "Segments need " << nExpectedPairCount << " coordinates, but Coordinates have only " << aPairs.getLength() << " pairs.");
-                    return;
+                    return false;
                 }
 
                 mpFS->startElementNS( XML_a, XML_custGeom, FSEND );
@@ -2450,10 +2450,11 @@ void DrawingML::WriteCustomGeometry( Reference< XShape > rXShape )
                 mpFS->endElementNS( XML_a, XML_path );
                 mpFS->endElementNS( XML_a, XML_pathLst );
                 mpFS->endElementNS( XML_a, XML_custGeom );
+                return true;
             }
         }
     }
-
+    return false;
 }
 
 void DrawingML::WritePolyPolygon( const tools::PolyPolygon& rPolyPolygon )
diff --git a/oox/source/export/shapes.cxx b/oox/source/export/shapes.cxx
index 9934bfa8d387..087f15d6592e 100644
--- a/oox/source/export/shapes.cxx
+++ b/oox/source/export/shapes.cxx
@@ -749,7 +749,9 @@ ShapeExport& ShapeExport::WriteCustomShape( Reference< XShape > xShape )
     else if (bCustGeom)
     {
         WriteShapeTransformation( xShape, XML_a, bFlipH, bFlipV );
-        WriteCustomGeometry( xShape );
+        bool bSuccess = WriteCustomGeometry( xShape );
+        if (!bSuccess)
+            WritePresetShape( sPresetShape );
     }
     else // preset geometry
     {