fix Invalid Read on conversion of ooo95991-1.odt to pdf

"Prepare" can delete the Portion belonging to the SwTxtFrm
and replace it. Prepare knows this and re-fetches it if
that happens. But Prepare can call itself and the outermost
Prepare doesn't know that the innermost Prepare replaced
the SwTxtFrm (and re-fetched it for the remainer of the
innermost Prepare).

So bubble out that it was re-fetched so the outer most
one re-fetches too

Invalid read of size 1

SwParaPortion::SetPrep(bool) (porlay.hxx:299)
SwTextFrm::Prepare(PrepareHint, void const*, bool) (txtfrm.cxx:1805)
SwContentFrm::MakeAll() (calcmove.cxx:1317)
SwFrm::PrepareMake() (calcmove.cxx:340)
SwFrm::Calc() const (frame.hxx:1004)
CalcContent(SwLayoutFrm*, bool, bool) (fly.cxx:1465)
SwLayoutFrm::FormatWidthCols(SwBorderAttrs const&, long, long) (wsfrm.cxx:3306)

Address 0x2137c850 is 832 bytes inside a block of size 840 free'd
free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
rtl_freeMemory_SYSTEM(void*) (alloc_global.cxx:277)
rtl_freeMemory (alloc_global.cxx:347)
rtl_cache_free (alloc_cache.cxx:1222)
FixedMemPool::Free(void*) (mempool.cxx:48)
SwParaPortion::operator delete(void*, unsigned long) (in /home/caolan/LibreOffice/core/instdir/program/libswlo.so)
SwParaPortion::~SwParaPortion() (porlay.cxx:1967)
SwTextFrm::ClearPara() (txtcache.cxx:106)
SwTextFrm::Init() (txtfrm.cxx:339)
SwTextFrm::CalcLineSpace() (txtfrm.cxx:792)
SwTextFrm::Prepare(PrepareHint, void const*, bool) (txtfrm.cxx:1724)
SwTextFrm::Prepare(PrepareHint, void const*, bool) (txtfrm.cxx:1706)
SwContentFrm::MakeAll() (calcmove.cxx:1317)
SwFrm::PrepareMake() (calcmove.cxx:340)
SwFrm::Calc() const (frame.hxx:1004)
CalcContent(SwLayoutFrm*, bool, bool) (fly.cxx:1465)
SwLayoutFrm::FormatWidthCols(SwBorderAttrs const&, long, long) (wsfrm.cxx:3306)

Change-Id: I1fdade2846e3cbd2e73be1f58d2597e9358fa0ea
(cherry picked from commit f703201d35f6e77940f68a21b339f67335b99441)

6 files changed, 36 insertions, 17 deletions

diff --git a/sw/source/core/inc/frame.hxx b/sw/source/core/inc/frame.hxx
index 0a23c88acc24..8d283f59e23a 100644
--- a/sw/source/core/inc/frame.hxx
+++ b/sw/source/core/inc/frame.hxx
@@ -770,7 +770,7 @@ public:
     // HACK: shortcut between frame and formatting
     // It's your own fault if you cast void* incorrectly! In any case check
     // the void* for 0.
-    virtual void Prepare( const PrepareHint ePrep = PREP_CLEAR,
+    virtual bool Prepare( const PrepareHint ePrep = PREP_CLEAR,
                           const void *pVoid = 0, bool bNotify = true );
 
     // true if it is the correct class, false otherwise
diff --git a/sw/source/core/inc/tabfrm.hxx b/sw/source/core/inc/tabfrm.hxx
index 3b418cf7f18b..c78872bc553a 100644
--- a/sw/source/core/inc/tabfrm.hxx
+++ b/sw/source/core/inc/tabfrm.hxx
@@ -133,7 +133,7 @@ public:
     virtual void Cut() SAL_OVERRIDE;
     virtual void Paste( SwFrm* pParent, SwFrm* pSibling = 0 ) SAL_OVERRIDE;
 
-    virtual void Prepare( const PrepareHint ePrep = PREP_CLEAR,
+    virtual bool Prepare( const PrepareHint ePrep = PREP_CLEAR,
                           const void *pVoid = 0, bool bNotify = true ) SAL_OVERRIDE;
 
                  SwContentFrm *FindLastContent();
diff --git a/sw/source/core/inc/txtfrm.hxx b/sw/source/core/inc/txtfrm.hxx
index 2d1418c49966..63ce3b938303 100644
--- a/sw/source/core/inc/txtfrm.hxx
+++ b/sw/source/core/inc/txtfrm.hxx
@@ -342,8 +342,11 @@ public:
      * SwContentFrm: the shortcut for the Frames
      * If the void* casts wrongly, it's its own fault!
      * The void* must be checked for 0 in any case!
+     *
+     * return true if the Portion associated with this SwTxtFrm was
+     * potentially destroyed and replaced by Prepare
      */
-    virtual void Prepare( const PrepareHint ePrep = PREP_CLEAR,
+    virtual bool Prepare( const PrepareHint ePrep = PREP_CLEAR,
                           const void *pVoid = 0, bool bNotify = true ) SAL_OVERRIDE;
 
     /**
diff --git a/sw/source/core/layout/tabfrm.cxx b/sw/source/core/layout/tabfrm.cxx
index 879bdff06afd..1fd119c59bab 100644
--- a/sw/source/core/layout/tabfrm.cxx
+++ b/sw/source/core/layout/tabfrm.cxx
@@ -3490,10 +3490,11 @@ void SwTabFrm::Paste( SwFrm* pParent, SwFrm* pSibling )
     }
 }
 
-void SwTabFrm::Prepare( const PrepareHint eHint, const void *, bool )
+bool SwTabFrm::Prepare( const PrepareHint eHint, const void *, bool )
 {
     if( PREP_BOSS_CHGD == eHint )
         CheckDirChange();
+    return false;
 }
 
 SwRowFrm::SwRowFrm(const SwTableLine &rLine, SwFrm* pSib, bool bInsertContent)
diff --git a/sw/source/core/layout/wsfrm.cxx b/sw/source/core/layout/wsfrm.cxx
index 6ab254e6b9aa..73ca1dd29ed8 100644
--- a/sw/source/core/layout/wsfrm.cxx
+++ b/sw/source/core/layout/wsfrm.cxx
@@ -332,9 +332,10 @@ void SwFrm::_UpdateAttrFrm( const SfxPoolItem *pOld, const SfxPoolItem *pNew,
     }
 }
 
-void SwFrm::Prepare( const PrepareHint, const void *, bool )
+bool SwFrm::Prepare( const PrepareHint, const void *, bool )
 {
     /* Do nothing */
+    return false;
 }
 
 /**
diff --git a/sw/source/core/text/txtfrm.cxx b/sw/source/core/text/txtfrm.cxx
index 4ce9409198d7..bc3e656bb4cd 100644
--- a/sw/source/core/text/txtfrm.cxx
+++ b/sw/source/core/text/txtfrm.cxx
@@ -1447,9 +1447,11 @@ static bool lcl_ErgoVadis( SwTextFrm* pFrm, sal_Int32 &rPos, const PrepareHint e
     return true;
 }
 
-void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
+bool SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                         bool bNotify )
 {
+    bool bParaPossiblyInvalid = false;
+
     SwFrmSwapper aSwapper( this, false );
 
 #if OSL_DEBUG_LEVEL > 1
@@ -1465,7 +1467,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 SetInvalidVert( true ); // Test
             case PREP_WIDOWS_ORPHANS:
             case PREP_WIDOWS:
-            case PREP_FTN_GONE :    return;
+            case PREP_FTN_GONE :    return bParaPossiblyInvalid;
 
             case PREP_POS_CHGD :
             {
@@ -1497,7 +1499,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 if ( GetDrawObjs() )
                     break;
 
-                return;
+                return bParaPossiblyInvalid;
             }
             default:
                 break;
@@ -1512,7 +1514,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
             InvalidateSize();
         else
             _InvalidateSize();
-        return;
+        return bParaPossiblyInvalid;
     }
 
     // Get object from cache while locking
@@ -1543,7 +1545,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
         case PREP_WIDOWS :
             // MustFit is stronger than anything else
             if( pPara->IsPrepMustFit() )
-                return;
+                return bParaPossiblyInvalid;
             // see comment in WidowsAndOrphans::FindOrphans and CalcPreps()
             PrepWidows( *static_cast<const sal_uInt16 *>(pVoid), bNotify );
             break;
@@ -1709,17 +1711,23 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
             else
             {
                 if( GetTextNode()->GetSwAttrSet().GetRegister().GetValue() )
-                    Prepare( PREP_REGISTER, 0, bNotify );
-
+                    bParaPossiblyInvalid = Prepare( PREP_REGISTER, 0, bNotify );
                 // The Frames need to be readjusted, which caused by changes
                 // in position
                 else if( HasFootnote() )
                 {
-                    Prepare( PREP_ADJUST_FRM, 0, bNotify );
+                    bParaPossiblyInvalid = Prepare( PREP_ADJUST_FRM, 0, bNotify );
                     _InvalidateSize();
                 }
                 else
-                    return; // So that there's no SetPrep()
+                    return bParaPossiblyInvalid; // So that there's no SetPrep()
+
+                if (bParaPossiblyInvalid)
+                {
+                    // It's possible that pPara was deleted above; retrieve it again
+                    pPara = aAccess.GetPara();
+                }
+
             }
             break;
         }
@@ -1730,7 +1738,9 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 CalcLineSpace();
 
                 // It's possible that pPara was deleted above; retrieve it again
+                bParaPossiblyInvalid = true;
                 pPara = aAccess.GetPara();
+
                 InvalidateSize();
                 _InvalidatePrt();
                 SwFrm* pNxt;
@@ -1756,7 +1766,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 if( nPos )
                     --nPos; // The char preceding our Follow
                 InvalidateRange( SwCharRange( nPos, 1 ), 0 );
-                return;
+                return bParaPossiblyInvalid;
             }
         case PREP_ERGOSUM:
         case PREP_QUOVADIS:
@@ -1773,7 +1783,7 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 sal_Int32 nWhere = CalcFlyPos( const_cast<SwFrameFormat *>(static_cast<SwFrameFormat const *>(pVoid)) );
                 OSL_ENSURE( COMPLETE_STRING != nWhere, "Prepare: Why me?" );
                 InvalidateRange( SwCharRange( nWhere, 1 ) );
-                return;
+                return bParaPossiblyInvalid;
             }
             // else: continue with default case block
         }
@@ -1802,11 +1812,15 @@ void SwTextFrm::Prepare( const PrepareHint ePrep, const void* pVoid,
                 else
                     _InvalidateSize();
             }
-            return; // no SetPrep() happened
+            return bParaPossiblyInvalid; // no SetPrep() happened
         }
     }
     if( pPara )
+    {
         pPara->SetPrep();
+    }
+
+    return bParaPossiblyInvalid;
 }
 
 /**