Related: fdo#71764 allow extensions button to group with help

even though they are in different containers

Change-Id: I785166c577acab03608da10fb4a33072458a82cd

sfx2/source/dialog/backingwindow.cxx

@@ -87,6 +87,26 @@ BackingWindow::BackingWindow( Window* i_pParent ) :
     get(mpHelpButton, "help");
     get(mpExtensionsButton, "extensions");
 
+    //Containers are invisible to cursor traversal
+    //So on pressing "right" when in Help the
+    //extension button is considered as a candidate
+    //
+    //But the containers are not invisible to the PushButton ctor which checks
+    //if the preceeding window of its parent is a button and if it then
+    //defaults to grouping with it and if it is not a button defaults to
+    //setting itself as the start of a new group.
+    //
+    //So here take the second button and set it as explicitly not the start
+    //of a group, i.e. allow it to be grouped with the preceeding
+    //PushButton so when seen as a candidate by cursor travelling
+    //it will be accepted as a continuation of the group.
+    WinBits nBits = mpExtensionsButton->GetStyle();
+    nBits &= ~WB_GROUP;
+    nBits |= WB_NOGROUP;
+    mpExtensionsButton->SetStyle(nBits);
+    assert(mpHelpButton->GetStyle() & WB_GROUP);
+    assert(!(mpExtensionsButton->GetStyle() & WB_GROUP));
+
     get(mpAllButtonsBox, "all_buttons_box");
     get(mpButtonsBox, "buttons_box");
     get(mpSmallButtonsBox, "small_buttons_box");