Description:
Crash if I paste a formula into the cell edit field.


Steps to Reproduce:
1. Open a csv in LibO Calc
2. Paste a formula into the cell edit box (to the right of the formula builder button), ex: =IF(D2 > "",DATEVALUE(D2)+TIMEVALUE(D2),D2)


Actual Results:
LibO crashes with the message
LibreOffice 6.4 - Fatal Error
Text forwarder is invalid, model might be dead

Expected Results:
Pasting formula should result in the formula being accepted as cell content


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 6.4.4.2
Build ID: 3d775be2011f3886db32dfd395a6a6d1ca2630ff
CPU threads: 4; OS: Mac OS X 10.15.6; UI render: default; VCL: osx; 
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded