[pacman-dev] some notes + new pactest file

[Nagy Gabor]

Hi!
1. As I see, can_remove_package should be replaced with direct call of
_alpm_checkdeps with TRANS_TYPE_REMOVE + check the reason flag
by hand, because the dependency check is not really sophisticated in
this function /and reimplemented/ .
2. _alpm_checkdeps doesn't really need trans param (neither in my
patched version nor the original imho <- its usage in cvs version
is messy for me)
3. Some words about speed again: We must make the "usual" decision
again:
a.) We prefer speed: we don't care about the fact
multiple provisions can exist on the system and we don't let pacman
remove the provision even if other package provides it too (current
state).
b.) We prefer "perfection": this is notably slower of course (if only
if the current version reports: package cannot be removed)
4. I repeat myself: all dependency check stuff from sync.c should be
moved (and rewritten) to deps.c.
5. That is very common in libalpm, that we search for a
depend-satisfyer, in most cases we forget check version number or
provides etc., so I think a "search_for_satisfyer" function would
vanish these bugs and reduce redundancies in the source (it's just a
for "pkg in pkgcache" alpm_depcmp(pkg,depend)). To show this, here is a
sync300.py file (see _alpm_resolvedeps for the "negligent"
search_for_satisfyer):
----------
Bye, ngaba
----------
self.description = "Corrupt database (broken deps)"

sp1 = pmpkg("pkg1")
sp1.depends = ["pkg2=1.0-2"]
self.addpkg2db("sync", sp1)

sp2 = pmpkg("pkg2", "1.0-1")
self.addpkg2db("sync", sp2)

self.args = "-S %s" % sp1.name

self.addrule("PACMAN_RETCODE=1")
self.addrule("!PKG_EXIST=pkg1")
self.addrule("!PKG_EXIST=pkg2")