Merge commands in the log window are no longer interactive in 4.6
Here's a sample transcript, where it assumes responses. A coworker installed 4.5.2, and it opens a messagebox prompt when this is replayed. I didn't try 4.5.2, but 4.6 is printing NUL on a black background just prior to the auto-filled response. I'm not sure if that's the issue, but I added it here as [NUL].
D:\dev\pcidrv% hg merge default
% hg merge default
subrepository include diverged (local revision: b6740e29d608, remote revision: 9a1073ad417b)
(M)erge, keep (l)ocal [working copy] or keep (r)emote [merge rev]?$$ &Merge $$ &Local $$ &Remote[NUL]m real URL is https://vcs.attotech.com:443/hg/sw/include
real URL is https://vcs.attotech.com:443/hg/sw/include
pulling subrepo include from https://vcs.attotech.com/hg/sw/pcidrv/include
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 9a1073ad417b
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
subrepository lib/cli diverged (local revision: efb98c9b4e7f, remote revision: 42b69728758b)
(M)erge, keep (l)ocal [working copy] or keep (r)emote [merge rev]?$$ &Merge $$ &Local $$ &Remote[NUL]m 5 files updated, 0 files merged, 0 files removed, 0 files unresolved
tool beyondcompare4 can't handle binary
tool tc can't handle binary
tool bcompare can't handle binary
tool beyondcompare4 can't handle binary
tool beyondcompare4-noauto can't handle binary
tool kdiff3 can't handle binary
tool beyondcompare2 can't handle binary
tool kdiff3-noauto can't handle binary
tool docdiff can't handle binary
no tool found to merge source/attofc/linux/attofc_x86_64.so
keep (l)ocal [working copy], take (o)ther [merge rev], or leave (u)nresolved for source/attofc/linux/attofc_x86_64.so?$$ &Local $$ &Other $$ &Unresolved[NUL]u 72 files updated, 0 files merged, 3 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[command returned code 1 Thu Jun 14 17:29:12 2018]
interrupted!