Meld - Mercurial

Description

Meld is a tool for making manual merges. It is a 3-way editor with visualization and propagation of differences.

Meld is available for Linux, MacOS, and Windows. On MacOS, Meld is available from MacPorts, Fink, and Homebrew. There are some notes available on how to get Meld running on Windows.

"Arrows" for propagation mode are toggled somehow with shift and control and alt
All 3 panes can be edited individually and must be saved individually
One way of working with Meld is to work towards making all 3 files equal - that forces you to review and rethink your merges in both contexts
Mercurial by default puts "file" is to the left, then "file~base", and finally "file~other"
By default then the left pane is the merge result
Enjoy that it is easy to see how the base version has diverged into two different versions
Changes from the new parent in "file~other" (to the right) can be propagated to "file" (to the left) through "file~base"
You could (and should?) start by copying everything from "file~other" to "file~base" in order to work with the two parents side-by-side - but then it is just a two-way merge...
Or, to change the order and which panes are displayed add a section "[merge-tools]" with "meld.args = $base $local $other" to your ~/.hgrc, specifying the order you prefer (since Meld's default order is different from some other diff tools)
To not see base at all set it to "meld.args = $local $other". You merge to the local copy, which in this arrangement is still the left pane

[merge-tools]
meld.priority = 1
meld.args = $base $local $other

Adding this to your .hgrc will give you a hg meldiff command to view diffs in Meld (of course you can call it what you like).

[extensions]
hgext.extdiff=

[extdiff]
cmd.meldiff = meld