Meld Window Does Not Appear on macOS Mojave

When running Meld on macOS Mojave, the Meld window will sometimes fail to appear.  The menu is there, but not the window.  Once this happens, it will stay broken until some saved state files are deleted:
rm -rf ~/Library/Saved\ Application\ State/org.gnome.meld.savedState/

The kludgey fix is to have the Meld start-up script do this for you. Add that line to /usr/local/Caskroom/meld/3.19.2-r6,osx-15/meld.wrapper.sh right before
exec '/Applications/Meld.app/Contents/MacOS/Meld' "$@"

Source: https://github.com/yousseb/meld/issues/70