fdo#78536: sfx2: template dialog: make the am-i-dead-yet check reentrant

In the fine tradition of our enterprise-grade code base, this lets the
check in SfxCommonTemplateDialog_Impl::Execute_Impl() do an early
return if the "this" instance has signalled its untimely demise even if
there are multiple calls of Execute_Impl() on the stack; extending
the scheme with further epicycles to make it work if the Execute_Impl()
calls happen on 2 different threads is left as an exercise for the
interested reader.

(regression from bcc52fb2ebdf77a1cc089857775fd742085b45b6)

Change-Id: I1d9f0d82bf6d9f5da8f9bd2be57d01937d71fd26

2 files changed, 11 insertions, 5 deletions

diff --git a/sfx2/source/dialog/templdlg.cxx b/sfx2/source/dialog/templdlg.cxx
index fd6b5ef1aa90..e59e14f44781 100644
--- a/sfx2/source/dialog/templdlg.cxx
+++ b/sfx2/source/dialog/templdlg.cxx
@@ -101,20 +101,22 @@ class SfxCommonTemplateDialog_Impl::DeletionWatcher : private boost::noncopyable
 public:
     explicit DeletionWatcher(SfxCommonTemplateDialog_Impl& rDialog)
         : m_pDialog(&rDialog)
+        , m_pPrevious(m_pDialog->impl_setDeletionWatcher(this))
     {
-        m_pDialog->impl_setDeletionWatcher(this);
     }
 
     ~DeletionWatcher()
     {
         if (m_pDialog)
-            m_pDialog->impl_setDeletionWatcher(0);
+            m_pDialog->impl_setDeletionWatcher(m_pPrevious);
     }
 
     // Signal that the dialog was deleted
     void signal()
     {
         m_pDialog = 0;
+        if (m_pPrevious)
+            m_pPrevious->signal();
     }
 
     // Return true if the dialog was deleted
@@ -125,6 +127,7 @@ public:
 
 private:
     SfxCommonTemplateDialog_Impl* m_pDialog;
+    DeletionWatcher *const m_pPrevious; /// let's add more epicycles!
 };
 
 // Re-direct functions
@@ -961,13 +964,16 @@ void SfxCommonTemplateDialog_Impl::impl_clear()
     DELETEZ( m_pStyleFamiliesId );
 }
 
-void SfxCommonTemplateDialog_Impl::impl_setDeletionWatcher(DeletionWatcher* pNewWatcher)
+SfxCommonTemplateDialog_Impl::DeletionWatcher *
+SfxCommonTemplateDialog_Impl::impl_setDeletionWatcher(
+        DeletionWatcher *const pNewWatcher)
 {
+    DeletionWatcher *const pRet(m_pDeletionWatcher);
     m_pDeletionWatcher = pNewWatcher;
+    return pRet;
 }
 
 
-
 void SfxCommonTemplateDialog_Impl::Initialize()
 {
     // Read global user resource
diff --git a/sfx2/source/inc/templdgi.hxx b/sfx2/source/inc/templdgi.hxx
index 3a3495338f8a..d313a6bc44ea 100644
--- a/sfx2/source/inc/templdgi.hxx
+++ b/sfx2/source/inc/templdgi.hxx
@@ -155,7 +155,7 @@ private:
     void    ReadResource();
     void    ClearResource();
     void impl_clear();
-    void impl_setDeletionWatcher(DeletionWatcher* pNewWatcher);
+    DeletionWatcher * impl_setDeletionWatcher(DeletionWatcher* pNewWatcher);
 
 protected:
 #define MAX_FAMILIES            5