Comment 5 for bug 1767961

I also hit this, with a consistent repro:

1) Launch Pinta
2) File > Open > select a file (I'm opening a jpg image)
3) Choose rectangle select tool from Tools grid
4) Attempt to select a rectangle in the image using the select tool

Results in crash almost immediately with the following debug spew:

free(): invalid pointer
Stacktrace:

  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) GLib.SList.g_free (intptr) <0x0005f>
  at GLib.ListBase.Empty () <0x0013c>
  at GLib.ListBase.Dispose (bool) <0x0000f>
  at GLib.ListBase.Finalize () <0x0001d>
  at (wrapper runtime-invoke) object.runtime_invoke_virtual_void__this__ (object,intptr,intptr,intptr) <0x00068>

Native stacktrace:

 /usr/bin/mono(+0xc8514) [0x5565eb610514]
 /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890) [0x7f73b7283890]
 /lib/x86_64-linux-gnu/libc.so.6(gsignal+0xc7) [0x7f73b6ca6e97]
 /lib/x86_64-linux-gnu/libc.so.6(abort+0x141) [0x7f73b6ca8801]
 /lib/x86_64-linux-gnu/libc.so.6(+0x89897) [0x7f73b6cf1897]
 /lib/x86_64-linux-gnu/libc.so.6(+0x9090a) [0x7f73b6cf890a]
 /lib/x86_64-linux-gnu/libc.so.6(cfree+0x4cc) [0x7f73b6cffe1c]
 [0x40c69270]

Debug info from gdb:

[New LWP 16118]
[New LWP 16119]
[New LWP 16120]
[New LWP 16121]
[New LWP 16152]