Ivan deletes things for no reason.

.git-prompt.sh

__gitdir ()
{
  # Note: this function is duplicated in git-completion.bash
  # When updating it, make sure you update the other one to match.
  if [ -z "${1-}" ]; then
    if [ -n "${__git_dir-}" ]; then
      echo "$__git_dir"
    elif [ -n "${GIT_DIR-}" ]; then
      test -d "${GIT_DIR-}" || return 1
      echo "$GIT_DIR"
    elif [ -d .git ]; then
      echo .git
    else
      git rev-parse --git-dir 2>/dev/null
    fi
  elif [ -d "$1/.git" ]; then
    echo "$1/.git"
  else
    echo "$1"
  fi
}

# stores the divergence from upstream in $p
# used by GIT_PS1_SHOWUPSTREAM
__git_ps1_show_upstream ()
{
  local key value
  local svn_remote svn_url_pattern count n
  local upstream=git legacy="" verbose=""

  svn_remote=()
  # get some config options from git-config
  local output="$(git config -z --get-regexp '^(svn-remote\..*\.url|bash\.showupstream)$' 2>/dev/null | tr '\0\n' '\n ')"
  while read -r key value; do
    case "$key" in
    bash.showupstream)
      GIT_PS1_SHOWUPSTREAM="$value"
      if [[ -z "${GIT_PS1_SHOWUPSTREAM}" ]]; then
        p=""
        return
      fi
      ;;
    svn-remote.*.url)
      svn_remote[ $((${#svn_remote[@]} + 1)) ]="$value"
      svn_url_pattern+="\\|$value"
      upstream=svn+git # default upstream is SVN if available, else git
      ;;
    esac
  done <<< "$output"

  # parse configuration values
  for option in ${GIT_PS1_SHOWUPSTREAM}; do
    case "$option" in
    git|svn) upstream="$option" ;;
    verbose) verbose=1 ;;
    legacy)  legacy=1  ;;
    esac
  done

  # Find our upstream
  case "$upstream" in
  git)    upstream="@{upstream}" ;;
  svn*)
    # get the upstream from the "git-svn-id: ..." in a commit message
    # (git-svn uses essentially the same procedure internally)
    local svn_upstream=($(git log --first-parent -1 \
          --grep="^git-svn-id: \(${svn_url_pattern#??}\)" 2>/dev/null))
    if [[ 0 -ne ${#svn_upstream[@]} ]]; then
      svn_upstream=${svn_upstream[ ${#svn_upstream[@]} - 2 ]}
      svn_upstream=${svn_upstream%@*}
      local n_stop="${#svn_remote[@]}"
      for ((n=1; n <= n_stop; n++)); do
        svn_upstream=${svn_upstream#${svn_remote[$n]}}
      done

      if [[ -z "$svn_upstream" ]]; then
        # default branch name for checkouts with no layout:
        upstream=${GIT_SVN_ID:-git-svn}
      else
        upstream=${svn_upstream#/}
      fi
    elif [[ "svn+git" = "$upstream" ]]; then
      upstream="@{upstream}"
    fi
    ;;
  esac

  # Find how many commits we are ahead/behind our upstream
  if [[ -z "$legacy" ]]; then
    count="$(git rev-list --count --left-right \
        "$upstream"...HEAD 2>/dev/null)"
  else
    # produce equivalent output to --count for older versions of git
    local commits
    if commits="$(git rev-list --left-right "$upstream"...HEAD 2>/dev/null)"
    then
      local commit behind=0 ahead=0
      for commit in $commits
      do
        case "$commit" in
        "<"*) ((behind++)) ;;
        *)    ((ahead++))  ;;
        esac
      done
      count="$behind  $ahead"
    else
      count=""
    fi
  fi

  # calculate the result
  if [[ -z "$verbose" ]]; then
    case "$count" in
    "") # no upstream
      p="" ;;
    "0  0") # equal to upstream
      p="=" ;;
    "0  "*) # ahead of upstream
      p=">" ;;
    *"  0") # behind upstream
      p="<" ;;
    *)      # diverged from upstream
      p="<>" ;;
    esac
  else
    case "$count" in
    "") # no upstream
      p="" ;;
    "0  0") # equal to upstream
      p=" u=" ;;
    "0  "*) # ahead of upstream
      p=" u+${count#0 }" ;;
    *"  0") # behind upstream
      p=" u-${count%  0}" ;;
    *)      # diverged from upstream
      p=" u+${count#* }-${count%  *}" ;;
    esac
  fi

}


# __git_ps1 accepts 0 or 1 arguments (i.e., format string)
# returns text to add to bash PS1 prompt (includes branch name)
__git_ps1 ()
{
  local g="$(__gitdir)"
  if [ -n "$g" ]; then
    local r=""
    local b=""
    if [ -f "$g/rebase-merge/interactive" ]; then
      r="|REBASE-i"
      b="$(cat "$g/rebase-merge/head-name")"
    elif [ -d "$g/rebase-merge" ]; then
      r="|REBASE-m"
      b="$(cat "$g/rebase-merge/head-name")"
    else
      if [ -d "$g/rebase-apply" ]; then
        if [ -f "$g/rebase-apply/rebasing" ]; then
          r="|REBASE"
        elif [ -f "$g/rebase-apply/applying" ]; then
          r="|AM"
        else
          r="|AM/REBASE"
        fi
      elif [ -f "$g/MERGE_HEAD" ]; then
        r="|MERGING"
      elif [ -f "$g/CHERRY_PICK_HEAD" ]; then
        r="|CHERRY-PICKING"
      elif [ -f "$g/BISECT_LOG" ]; then
        r="|BISECTING"
      fi

      b="$(git symbolic-ref HEAD 2>/dev/null)" || {

        b="$(
        case "${GIT_PS1_DESCRIBE_STYLE-}" in
        (contains)
          git describe --contains HEAD ;;
        (branch)
          git describe --contains --all HEAD ;;
        (describe)
          git describe HEAD ;;
        (* | default)
          git describe --tags --exact-match HEAD ;;
        esac 2>/dev/null)" ||

        b="$(cut -c1-7 "$g/HEAD" 2>/dev/null)..." ||
        b="unknown"
        b="($b)"
      }
    fi

    local w=""
    local i=""
    local s=""
    local u=""
    local c=""
    local p=""

    if [ "true" = "$(git rev-parse --is-inside-git-dir 2>/dev/null)" ]; then
      if [ "true" = "$(git rev-parse --is-bare-repository 2>/dev/null)" ]; then
        c="BARE:"
      else
        b="GIT_DIR!"
      fi
    elif [ "true" = "$(git rev-parse --is-inside-work-tree 2>/dev/null)" ]; then
      if [ -n "${GIT_PS1_SHOWDIRTYSTATE-}" ]; then
        if [ "$(git config --bool bash.showDirtyState)" != "false" ]; then
          git diff --no-ext-diff --quiet --exit-code || w="*"
          if git rev-parse --quiet --verify HEAD >/dev/null; then
            git diff-index --cached --quiet HEAD -- || i="+"
          else
            i="#"
          fi
        fi
      fi
      if [ -n "${GIT_PS1_SHOWSTASHSTATE-}" ]; then
        git rev-parse --verify refs/stash >/dev/null 2>&1 && s="$"
      fi

      if [ -n "${GIT_PS1_SHOWUNTRACKEDFILES-}" ]; then
        if [ -n "$(git ls-files --others --exclude-standard)" ]; then
          u="%"
        fi
      fi

      if [ -n "${GIT_PS1_SHOWUPSTREAM-}" ]; then
        __git_ps1_show_upstream
      fi
    fi

    local f="$w$i$s$u"
    printf -- "${1:- (%s)}" "$c${b##refs/heads/}${f:+ $f}$r$p"
  fi
}