Description:
An inserted image was selected and text added.  The text was on several lines- "Abc def" <NL> <NL> <NL> "123 456".  The last line selected, text size reduced 4 points. The last 2 <NL> were selected by <Shift><back-arrow>.  Then using the Character... dialog box to change "text" size (i.e. line size), crash occurred upon [ OK ] to do change.  Problem is repeatable.

Steps to Reproduce:
1. Insert image (.jpg in my case); select it
2. Add text to image
3. Change Alignment of text to [Top][Center]
4. Enter multiple line text - line at top with some chars, couple of
   blank lines (hit [Enter] on keyboard a couple of times, type some
   more chars on the last line
5. Select chars on last line and reduce font size a few points; success
6. Move cursor to beginning of this last line
7. Use <Shift><back-arrow> to select under cursor far enough to
   move the cursor back upwards a couple of blank lines
   -- note: I did not back up far enough to reach the chars on
      the 1st (unchanged) line
8. Use [Character...] dialog box to attempt to change size of the
   blank lines downward a couple of points (in my case from 16 to 12)
9. Crash occurs on poke [ OK ] button

Actual Results:  
Application crash

Note: Automatic bugzilla report generation also failed because traceback of Draw could not be successfully generated -- even though 100 "debuginfo files were successfully downloaded.

Expected Results:
First and last lines (with text) move a bit closer together because
the height of the intervening (blank) lines is reduced.


Reproducible: Always


User Profile Reset: No



Additional Info:
[Information automatically included from LibreOffice]
Locale: en-US
Module: DrawingDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes


User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.75 Safari/537.36