Erroneous display of branch ancestry after rebase and merge

The same bug was already reported in SRCTREE-1818 for the Mac version, but also affects the Windows version.

After rebases and merges, I often end up with a wrong history graph of my Git commits. Branches get detached from the rest of the tree in Date Order view, where some commits lose their ancestor.

In my latest case, this happened after a rebase from branch A with commits a1...a4 to branch B with commits b1..b4, then a fast-forward merge from B to a1. Now B consists of b1..b4,a1 and A is completely detached from B, consisting only of the previously rebased commits a2..a4.

So, before rebase:

b1--b2--b3--b4[B]
         |
         +--a1--a2--a3--a4[A]

After rebase of A onto B:

b1--b2--b3--b4[B]--a1--a2--a3--a4[A]

EXPECTED after fast-forward merge of B to a1:

b1--b2--b3--b4--a1[B]--a2--a3--a4[A]

ACTUALLY after fast-forward merge of B to a1:

b1--b2--b3--b4-----------------a1[B]

----------------a2--a3--a4[A]