bug#19851: 25.0.50; package-install-{file,from-buffer} broken

[Mark Oteiza <mvoteiza@udel.edu>]

In GNU Emacs 25.0.50.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw scroll bars)
 of 2015-02-12 on logos
Repository revision: e39d96ebe4c342885433afc28232197ce398fe71

Hi,

These functions are broken on master.  For instance,

1. ~ $ git clone http://mumble.net/~campbell/git/paredit.git
2. emacs -Q
3. M-x package-install-file RET ~/paredit RET

Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
  package-install-from-buffer()
  package-install-file("~/paredit/")
  funcall-interactively(package-install-file "~/paredit/")
  call-interactively(package-install-file record nil)
  command-execute(package-install-file record)
  execute-extended-command(nil "package-install-file" "package-install-fi")
  funcall-interactively(execute-extended-command nil "package-install-file" "package-install-fi")
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)