fdo#58204: PPT export: fix text rotation in shapes:

EscherPropertyContainer::CreateTextProperties: do not write
ESCHER_Prop_txflTextFlow for custom shapes.  This happens to export the
rotation properly for the WW8 bugdoc of n#404221, as well as the PPT at
fdo#58204 and both PPTs at fdo#34897, one of which (mangle.ppt) was not
handled properly on master currently.  The author disclaims having any
actual knowledge about rotation properties in MSO files.

(regression from 24dd42f3)

(cherry picked from commit 2823789b)

Conflicts:
	filter/source/msfilter/escherex.cxx

Change-Id: Id3dcfb6221d031cdabb7f543b68752b467d9e1a6
Reviewed-on: https://gerrit.libreoffice.org/1862Tested-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>
Reviewed-by: Bosdonnat Cedric <cedric.bosdonnat@free.fr>

filter/source/msfilter/escherex.cxx

@@ -682,7 +682,9 @@ void EscherPropertyContainer::CreateTextProperties(
 
     // n#404221: In case of rotation we need to write the txtflTextFlow
     // attribute too.
-    if (bIsTextFrame) {
+    // fdo#58204: not custom shapes (TODO: other cases when it doesn't work?)
+    if (bIsTextFrame && !bIsCustomShape)
+    {
         sal_uInt16 nAngle = EscherPropertyValueHelper::GetPropertyValue(
         aAny,
         rXPropSet,