commands: allow --closed even for topological heads displays
But it actually only starts working later on.
% test multiple merges at once
initializing destination source-hg repository
scanning source...
sorting...
converting...
4 Initial add
3 Added branch1 file
2 Added parent file
1 Added brach2 file
0 Merged branches
o 5 "(octopus merge fixup)" files:
|\
| o 4 "Merged branches" files: file-branch2
| |\
o---+ 3 "Added brach2 file" files: file-branch2
/ /
| o 2 "Added parent file" files: file-parent
| |
o | 1 "Added branch1 file" files: file file-branch1
|/
o 0 "Initial add" files: file
% manifest of tip
644 file
644 file-branch1
644 file-branch2
644 file-parent