Opening a particular .odt file makes OOo crash. The crash happens when it tries
to layout the document.

It appears to have to do with footnotes. The document also uses the U+2060 "WORD
JOINER" character in many places.

Here is the top of a debug backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
(gdb) bt
#0  0x0000000000000000 in ?? ()
#1  0x00007fffda6c8d0d in SwFrm::PrepareMake (this=0x7fffd346da88)
    at /xxx/OOO320_m12/sw/source/core/layout/calcmove.cxx:396
#2  0x00007fffda609936 in SwFrm::Calc (this=0x7fffd346da88)
    at ../inc/frame.hxx:1060
#3  0x00007fffda708f25 in SwFtnBossFrm::RearrangeFtns (this=0x7fffd9cf10c0, 
    nDeadLine=25512, bLock=1 '\001', pAttr=0x0)
    at /xxx/OOO320_m12/sw/source/core/layout/ftnfrm.cxx:2601
#4  0x00007fffda81d996 in SwTxtFrm::ConnectFtn (this=0x7fffd9cf4658, 
    pFtn=0x7fffd1ecfe10, nDeadLine=25512)
    at /xxx/OOO320_m12/sw/source/core/text/txtftn.cxx:823
#5  0x00007fffda81dda7 in SwTxtFormatter::NewFtnPortion (this=0x7fffffff9d60, 
    rInf=..., pHint=0x7fffd1ecfe10)
    at /xxx/OOO320_m12/sw/source/core/text/txtftn.cxx:898
#6  0x00007fffda807a25 in SwTxtFormatter::NewExtraPortion (
    this=0x7fffffff9d60, rInf=...)
    at /xxx/OOO320_m12/sw/source/core/text/txtfld.cxx:344
#7  0x00007fffda7d7041 in SwTxtFormatter::NewPortion (this=0x7fffffff9d60, 
    rInf=...)
    at /xxx/OOO320_m12/sw/source/core/text/itrform2.cxx:1330
#8  0x00007fffda7d517e in SwTxtFormatter::BuildPortions (this=0x7fffffff9d60, 
    rInf=...)
    at /xxx/OOO320_m12/sw/source/core/text/itrform2.cxx:714
#9  0x00007fffda7d7b40 in SwTxtFormatter::FormatLine (this=0x7fffffff9d60, 
    nStartPos=307)
    at /xxx/OOO320_m12/sw/source/core/text/itrform2.cxx:1552