I’m not sure how to describe other than a formula error in the Formula Wizard crashes the system.
I’m able to duplicate this with the following steps:
Create brand new file
Add a new piece
Add line connecting to A. When the Point at Distance and Angle dialog box opens up, then enter any kind of formula you but end it with – (two minus signs). What I was trying to enter was Hip_Arc_Back / 2 - 0.5, only I hit the minus key a second time instead of 0. The system crashes on the 2nd minus.
Alternate step 3: Use the Edit Length dialog instead. It crashes in the same place in the formula.
Other notes: ± and *- also kill it .
Strangely enough, it doesn’t have a problem with ++, -+, -*. It appears to have a problem with minus being last althought I didn’t test all the combinations.
trying the num-- on my debianVM with the Nov 11 AppImage
Point at Distance and Angle Enter -- at the end of the formula line
DEBUG:Point label: A1
DEBUG: Code: 2 ( "Unexpected end of expression at position 9" )
Segmentation fault (core dumped)
& Seamly2D is no longer open. Reopen Seamly2D for more experimenting.
entered -+ at the end of the formula, & the terminal reads this error, but it doesn’t crash:
DEBUG:
Math parser error:
--------------------------------------
Message: "Unexpected operator \"+\" found at position 9"
Expression: "4.723071-+------ "
--------------------------------------
(actually, that one was after I added a whole string of dash.)
Hi @sandmanmax!
Thanks for pointing this out to us.
Please add this as an issue on our github repo.
You’ll need to create a github account if you don’t already have one.
Thanks!
Confirmed. Same (existing) error on Windows. Errors happens on any formula when the “minus” char is entered immediately after any invalid char. Surprised it’s gone this long without a report.
I have a fix, will make a PR layer this afternoon.
Update: Just did a last minute check after pulling in changes from develop before making a PR. No crash.
Enter 
