git-functions

#!/bin/bash

# meldgit and variants open meld with an editable comparison of a file and
# it's version from HEAD, upstream, or origin.
meldgit ()         { (meldgit-implementation HEAD $1) }
meldgitupstream () { (meldgit-implementation $(git merge-base @{upstream} HEAD) $1) }
meldgitorigin ()   { (meldgit-implementation $(git merge-base origin/HEAD HEAD) $1) }
meldgitish ()      { (meldgit-implementation $1 $2) }
meldgitall ()         { (meldgitall-implementation HEAD) }
meldgitupstreamall () { (meldgitall-implementation $(git merge-base @{upstream} HEAD)) }
meldgitoriginall ()   { (meldgitall-implementation $(git merge-base origin/HEAD HEAD)) }
meldgitishall ()      { (meldgitall-implementation $1) }

# Why not just git difftool? Because if the file has no edits yet it won't launch a diff.
#   git difftool --tool meld HEAD:$(git ls-files --full-name -- $1) $1
meldgit-implementation () {
  base_branch=$1
  file=$2
  if [ "$file." == "." ]; then
    echo specify a file
  else
    meld <(git show $base_branch:$(git ls-files --full-name -- $file)) $file
  fi
}

meldgitall-implementation () {
  base_branch=$1
  if [ "base_branch." == "." ]; then
    echo specify a base_branch for git diff
  else
    gitnames=$(git diff --name-only $base_branch)
    for file in $gitnames; do
      read -p "meldgit $file [Yy]? " -n 1
      if [[ $REPLY != "" ]]; then echo; fi
      if [[ $REPLY =~ ^[Yy]$ ]] || [[ $REPLY == "" ]]; then
        meldgit-implementation $base_branch $file &
      fi
    done
  fi
}