Default target branch selection - use first "parent" branch
### Problem to solve
At our place we have several branches and do not always merge into "master". So in 90% of the time the pre-selected "master" is wrong.
### Intended users
All developers creating merge requests.
### Further details
I create from RELEASE/MyApp/1.2 a new development branch (i.e. DEV/MyApp/1.2/TASK-1) to develop a feature for 1.2, I later want to merge this again back to 1.2 and not to master.
But when creating a new MR, the default branch (master) will be selected.
### Proposal
Gitlab should check which is the nearest parent to my current branch (i.e. DEV/MyApp/1.2/TASK-1) -- which will be RELEASE/MyApp/1.2 as this was the source of branching there. So it should propose **RELEASE/MyApp/1.2** as default target branch.
### Permissions and Security
Developer permissions
### Documentation
It should be documented, which parameter changes the behaviour of selecting "default" branch as default target or the nearest parent branch. Also that feature itself should be documented.
### Testing
When creating a new MR the target branch will be the nearest parent branch.
That behaviour should be configurable to allow others still to have master as default, if they want.
### What does success look like, and how can we measure that?
Configure default behaviour of target branch, change to "nearest parent branch" instead of "master".
Create a example release branch like:
RELEASE/MyApp/1.2
Create a new branch on top of this branch with for example "DEV/MyApp/1.2/TASK-1"
Create a MR for DEV/MyApp/1.2/TASK-1
Expection: Default target should be **RELEASE/MyApp/1.2**
### Links / references
issue