After auto break line or merge line, the undo don't work

[vernou]

Expected Behavior

It's possible to undo (Ctr+z) all modification.

Actual Behavior

After auto break line or merge line, the undo don't work.

Steps to reproduce the behavior

C:\TMP\Path1;
C:\TMP\Path2;
C:\TMP\Path3;
C:\TMP\Path4;

Remove ';' in second line :

C:\TMP\Path1;
C:\TMP\Path2C:\TMP\Path3;
C:\TMP\Path4;

Press Ctr+z, the modification isn't reversed.