First let me say that I titled it a bug while it is not vital (despite being quite awkward).
To be clear, I'll explain it calling "preselect" when you first select the items then the operation, and "postselect" when you first select the operation then the items.
Now to demonstrate the issue :
- Create a new sketch and check "Auto Remove Redundants" is enabled
- Create 2 lines (let's call them A & B, and their respective endpoints x.1 & x.2)
- Select line A and endpoint B.1, then add a Point-on-line constraint
- (Preselect mode): Select endpoints A.1 & B.1, then add a Coincident constraint => Everything's fine, Point-on-line constraint is removed
- Come back to the state at the end of step 3
- (Postselect mode): Select Coincident constraint (w/o anything selected), then click on A1 & B1 => Ouch ! Sketch isn't updated and solver displays "Sketch contains redundant constraints". Now just drag any line/endpoint with the mouse => Sketch is now updated and redundant constraint is removed
Thanks for confirming.
OS: Ubuntu 18.04.2 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15860 (Git)
Build type: Release
Python version: 2.7.15rc1
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/France (fr_FR)