Resolves: fdo#68967 looping layout

RemoveFollowFlowLine() marks the layout invalid, but the
next cycle through does everything exactly the same again.

Try the same foul horror as nUnSplitted. But at least with
a test-case that nails down reproducing the bug if a better
fix is needed.

Change-Id: Id6698bcb2364bd0253bedd4a7c313e25f705be8d

sw/qa/extras/ww8import/ww8import.cxx

@@ -510,6 +510,10 @@ DECLARE_WW8IMPORT_TEST(testBnc787942, "bnc787942.doc")
     parseDump("/root/page[1]/body/txt[4]/anchored");
 }
 
+DECLARE_WW8IMPORT_TEST(testLayoutHanging, "fdo68967.doc")
+{
+    // This must not hang in layout
+}
 
 CPPUNIT_PLUGIN_IMPLEMENT();
 

sw/source/core/layout/tabfrm.cxx

@@ -1831,6 +1831,7 @@ void SwTabFrm::MakeAll()
     }
 
     int nUnSplitted = 5; // Just another loop control :-(
+    int nThrowAwayValidLayoutLimit = 5; // And another one :-(
     SWRECTFN( this )
     while ( !mbValidPos || !mbValidSize || !mbValidPrtArea )
     {
@@ -2301,7 +2302,13 @@ void SwTabFrm::MakeAll()
                     // An existing follow flow line has to be removed.
                     if ( HasFollowFlowLine() )
                     {
+                        if (!nThrowAwayValidLayoutLimit)
+                            continue;
+                        bool bInitialLoopEndCondition = mbValidPos && mbValidSize && mbValidPrtArea;
                         RemoveFollowFlowLine();
+                        bool bFinalLoopEndCondition = mbValidPos && mbValidSize && mbValidPrtArea;
+                        if (bInitialLoopEndCondition && !bFinalLoopEndCondition)
+                            --nThrowAwayValidLayoutLimit;
                     }
 
                     const bool bSplitError = !Split( nDeadLine, bTryToSplit, ( bTableRowKeep && !bAllowSplitOfRow ) );