package-installed-p broken

[Sebastian Wiesner]

Hello,

after "package-install", "package-installed-p" still returns nil for
the package that was just installed.  Consider:

ELISP> (package-installed-p 'nrepl)
nil
ELISP> (package-install (cdr (assq 'nrepl package-archive-contents)))
nil
ELISP> (package-installed-p 'nrepl)
nil
ELISP> (package-initialize)
t
ELISP> (package-installed-p 'nrepl)
t

Also, before "package-initialize", the newly installed "nrepl" package
still appears as "available", but not as "installed" in "M-x
list-packages".

Even worse, dependency resolution is now broken, likely as a result of
this misbehavior of "package-installed-p".  Consider "hardhat" and
"ignoramus", where "hardhat" depends on "ignoramus".  If I explicitly
install "ignoramus", "hardhat" cannot be installed afterwards:

ELISP> (package-installed-p 'ignoramus)
nil
ELISP> (package-installed-p 'hardhat)
nil
ELISP> (cdr (assq 'hardhat package-archive-contents))
[cl-struct-package-desc hardhat
                        (20130522 1243)
                        "Protect against clobbering user-writable
files [github]"
                        ((ignoramus
                          (0 6 2)))
                        single "melpa" nil]

ELISP> (package-install (cdr (assq 'ignoramus package-archive-contents)))
nil
ELISP> (package-install (cdr (assq 'hardhat package-archive-contents)))
*** Eval error ***  File exists:
/Users/swiesner/.emacs.d/elpa/ignoramus-20130522.1245/ignoramus-pkg.el
ELISP> (package-initialize)
t
ELISP> (package-installed-p 'ignoramus)
t
ELISP> (package-install (cdr (assq 'hardhat package-archive-contents)))
nil

As you can see, when installing "hardhat", package.el still attempts
to install ignoramus though this package is already installed.

The packages mentioned in this mail are from the MELPA archive.

Sincerely,
Sebastian Wiesner