Attached is a very simple project: a Form with 2 Memos and a Splitter.
I followed this example:
http://wiki.freepascal.org/TSplitter#Splitter_with_AnchorSidesMemo1 is anchored at top, left and bottom to a Form, at right - to Splitter.
Memo2 is anchored at top, right and bottom to a Form, at left - to Splitter.
Both Memos have Costraints.MinHeight and MinWidth, also do Form.
All align properties are set to alNone.
How to reproduce a problem:
Start application
Enlarge the form's width well enough
Using Splitter, minimize Memo1 to the possible minimum width
(up to now everything works fine)
Now drag right frame of a form to minimize the width.
Memo2 with Splitter starts to overlap Memo1.
I can't believe that this is a bug which nobody have noticed.
That's why I played few days with this issue to find out what I'm doing wrong.
Creating different projects with similar settings, I noticed that effect have random nature:
Sometimes Memo1 is overlapped by Splitter and Memo2,
Sometimes Splitter with Memo2 are dragged under Memo1 which looks transparent in that case.
Seems this depends upon the order of settings were done while designing the form and the controls, but I didn't find out the rule.
Lazarus 1.8.4
Windows 7