#
  # <public>
  proc stagePackageFiles { language version platform fileNames } {
    variable checkoutDirectory
    variable fossilAddCommand

    if {![verifyThereAreNoChanges]} then {
      error "cannot stage files: there are pending changes"
    }

    if {![verifyThisIsTheCorrectProject]} then {
      error "cannot stage files: wrong project"
    }

    if {![verifyThisIsTheCorrectBranch]} then {
      changeToTheCorrectBranch

      if {![verifyThisIsTheCorrectBranch]} then {
        error "cannot stage files: still on wrong branch"
      }
    }

    set newFileNames [list]

    foreach fileName $fileNames {
      if {![createOpenPgpSignature $fileName]} then {
        error [appendArgs \
            "cannot stage file \"" $fileName "\": OpenPGP signing failed"]
      }

      lappend newFileNames $fileName
      lappend newFileNames [appendArgs $fileName .asc]
    }

    set relativeFileNames [getRelativeFileNames $newFileNames]

    foreach fileName $newFileNames relativeFileName $relativeFileNames {
      file mkdir [file join \
          $checkoutDirectory $language $version $platform \
          [file dirname $relativeFileName]]

      file copy $fileName \
          [file join $checkoutDirectory $relativeFileName]

    variable argumentData

    if {[isEagle]} then {
      set sender [lindex $args 0]; # NOTE: Disposal.
      set e [lindex $args 1]; # NOTE: Disposal.
    }

    if {[haveArgumentData]} then {
      set apiKey $argumentData(apiKey)
      set package $argumentData(package)
      set patchLevel $argumentData(patchLevel)
      set language $argumentData(language)
      set version $argumentData(version)
      set platform $argumentData(platform)
      set fileNames $argumentData(fileNames)

      ::PackageRepository::probeForOpenPgpInstallation
      ::PackageRepository::openPgpMustBeInstalled

      #
      # NOTE: THIS BLOCK REFERS TO SEVERAL UNTESTED PROCEDURES.
      #
      if {0} then {
        stagePackageFiles $language $version $platform $fileNames

        if {![commitPackageFiles \
            $package $patchLevel $language $version checkin]} then {
          error "failed to commit package files"
        }

        set script [createRepositoryScript \
            "" $checkin $language $version $platform $fileNames [list]]

        set scriptFileName [file join \
            [::PackageRepository::getFileTempDirectory PKGR_UPLOAD_TEMP] \
            [appendArgs pkgr_upload_ [::PackageRepository::getUniqueSuffix]]]

        writeFile $scriptFileName $script

        if {![createOpenPgpSignature $scriptFileName]} then {
          error [appendArgs \
              "cannot submit package metadata: OpenPGP signing of \"" \
              $scriptFileName "\" failed"]
        }

        set certificate [readFile [appendArgs $scriptFileName .asc]]

        submitPackageMetadata \
            $apiKey $package $patchLevel $language $script $certificate
      }
    } else {
      error "cannot initiate package submission: one or more fields missing"
    }
  }

  #
  # NOTE: This procedure is an event handler.  It handles the clear button in
  #       Tk and Eagle.  It is used to clear the package submission data.  The
  #       args argument is not really used, it is a placeholder to make this
  #       procedure more portable between Tcl and Eagle.  This procedure may