/etc/bash_completion.d/dpatch_edit_patch is in dpatch 2.0.34ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 | #-*- mode: shell-script;-*-
# Inputs:
#   $1 -- name of the command whose arguments are being completed
#   $2 -- word being completed
#   $3 -- word preceding the word being completed
#   $COMP_LINE  -- current command line
#   $COMP_PONT  -- cursor position
#   $COMP_WORDS -- array containing individual words in the current
#                  command line
#   $COMP_CWORD -- index into ${COMP_WORDS} of the word containing the
#                  current cursor position
# Output:
#   COMPREPLY array variable contains possible completions
#
# Syntax:
#   dpatch-edit-patch [options] command dpatchname [basepatch]
#
have dpatch-edit-patch &&
_dpatch_edit_patch()
{
    local shopt_aliases_opt i cur prev mode options rootcmds patches patchlist DPEP_DO_GETOPTION
    local DPEP_SOURCEDIR DPEP_OUTDIR DPEP_TMPDIR DPEP_ROOTCMD DPEP_NEWDESC DPEP_KEEPTEMP
    local conf_sourcedir conf_outdir conf_tmpdir conf_rootcmd conf_newdesc conf_keeptemp
    case "$(shopt expand_aliases)" in
	 *on) shopt_aliases_opt="-s";;
	*off) shopt_aliases_opt="-u";;
    esac
    shopt -u expand_aliases
    COMPREPLY=()
    cur=${COMP_WORDS[COMP_CWORD]}
    prev=${COMP_WORDS[COMP_CWORD-1]}
    # options
    options='-s -o -r -d -k -t --sourcedir --outdir --rootcmd \
             --description --keeptemp --tmpdir'
    rootcmds='fakeroot sudo'
    # commands (added to patches)
    patches=patch
    # Read in the user's configuration file, should it exist.
    [[ -f ~/.dpatch.conf ]] && . ~/.dpatch.conf
    # default dirs
    DPEP_SOURCEDIR=${DPEP_SOURCEDIR:-${conf_sourcedir:-$(pwd)}}
    DPEP_OUTDIR=${DPEP_OUTDIR:-${conf_outdir:-$DPEP_SOURCEDIR/debian/patches}}
    # parse options
    mode=all
    for (( i=1; i < ${#COMP_WORDS[@]}; i++ )); do
        arg="${COMP_WORDS[$i]}"
        #echo "i=$i arg=\"$arg\""
        if [ -z "$arg" ]; then
            if [ -z "$DPEP_DO_GETOPTION" ]; then
                mode=all
            fi
            continue
        fi
        if [ -n "$DPEP_DO_GETOPTION" ]; then
            eval "$DPEP_DO_GETOPTION$arg"
            DPEP_DO_GETOPTION=""
            continue
        fi
        case "$arg" in
        -s|--sourcedir)
            DPEP_DO_GETOPTION="DPEP_SOURCEDIR="
            options=${options//+(-s|--sourcedir)/}
            mode=file
            ;;
        --sourcedir=*)
            DPEP_SOURCEDIR="$(printf "%s" "$arg" | cut -f2- -d= )"
            options=${options//+(-s|--sourcedir)/}
            cur=${cur/--sourcedir=/}
            mode=file
            ;;
        -o|--outdir)
            DPEP_DO_GETOPTION="DPEP_OUTDIR="
            options=${options//+(-o|--outdir)/}
            mode=file
            ;;
        --outdir=*)
            DPEP_OUTDIR="$(printf "%s" "$arg" | cut -f2- -d= )"
            options=${options//+(-o|--outdir)/}
            cur=${cur/--outdir=/}
            mode=file
            ;;
        -t|--tmpdir)
            DPEP_DO_GETOPTION="DPEP_TMPDIR="
            options=${options//+(-t|--tmpdir)/}
            mode=file
            ;;
        --tmpdir=*)
            DPEP_TMPDIR="$(printf "%s" "$arg" | cut -f2- -d= )"
            options=${options//+(-t|--tmpdir)/}
            cur=${cur/--tmpdir=/}
            mode=file
            ;;
        -r|--rootcmd)
            DPEP_DO_GETOPTION="DPEP_ROOTCMD="
            options=${options//+(-r|--rootcmd)/}
            mode=rootcmd
            ;;
        --rootcmd=*)
            DPEP_ROOTCMD="$(printf "%s" "$arg" | cut -f2- -d= )"
            options=${options//+(-r|--rootcmd)/}
            mode=all
            ;;
        -d|--description)
            DPEP_DO_GETOPTION="DPEP_NEWDESC="
            options=${options//+(-d|--description)/}
            mode=file
            ;;
        --description=*)
            DPEP_NEWDESC="$(printf "%s" "$arg" | cut -f2- -d= )"
            options=${options//+(-d|--description)/}
            mode=file
            ;;
        -*)
            mode=options
            ;;
        patch)
            mode=patch
            patches=""
            ;;
        *)
            mode=patch
            ;;
        esac
    done
    #echo "mode=$mode"
    case "$mode" in
    options)
        # standard completion on options
        COMPREPLY=( $( compgen -W "$options" -- "$cur" ) )
        ;;
    none)
        # the user has to type a text
        return 0
        ;;
    file)
        # files and directories
        _filedir
        ;;
    rootcmd)
        # a root command
        COMPREPLY=( $( compgen -W "$rootcmds" -- "$cur" ) )
        ;;
    patch|all)
        # a list of patches ("patch") or all options and patches ("all")
        if [ "$mode" = "all" ]; then
            COMPREPLY=( $( compgen -W "$options" -- "$cur" ) )
        fi
        # check for debian source dir
        if [ ! -e "$DPEP_SOURCEDIR/debian/rules" ]; then
            return 0
        fi
        # check for output dir
        if [ ! -d "$DPEP_OUTDIR" ]; then
            return 0
        fi
        # search patches
        patchlist=$(ls $DPEP_OUTDIR/00list* 2>/dev/null)
        if [ -z "$patchlist" ]; then
            return 0
        fi
        patches="$(cat $patchlist | grep -v ^\# 2>/dev/null) $patches"
        COMPREPLY=( ${COMPREPLY[@]} $( compgen -W "$patches" -- "$cur" ) )
        ;;
    esac
    shopt "$shopt_aliases_opt" expand_aliases
    return 0
}
[ "$have" ] && complete -F _dpatch_edit_patch $filenames dpatch-edit-patch
# arch-tag: 448345aa-f5c7-4e20-89d7-4f7df0288228
 |