Easily visualise Git merge.conflictstyle diff3 with meld, while preserving all information

.gitconfig

[merge]
    conflictstyle = diff3
    tool = three_meld
[mergetool "three_meld"]
    # Opens up four diff windows:
    # LOCAL:MERGED, BASE:LOCAL, BASE:REMOTE, LOCAL:REMOTE
    #
    # Lets you edit the MERGED file (including original diff3 markers), showing
    # you the final diff from LOCAL.  For reference, you can look in the other
    # windows to see how LOCAL and REMOTE are each different from BASE, as well
    # as the dumb diff between LOCAL and REMOTE.
    cmd = "env LOCAL=\"$LOCAL\" REMOTE=\"$REMOTE\" BASE=\"$BASE\" MERGED=\"$MERGED\" bash -c 'meld --diff \"$LOCAL\" \"$MERGED\" --diff \"$BASE\" \"$LOCAL\" --diff \"$BASE\" \"$REMOTE\" --diff \"$LOCAL\" \"$REMOTE\"'"