Add SyncFirst option.

This patch offers a way to fix FS#9228.
By putting "SyncFirst = pacman" in pacman.conf, the version check will
happen before the transaction really starts, and before any replacements is
made.
Otherwise, no version check is done.

The sync301 pactest was updated to use this SyncFirst option.

Example session with SyncFirst = pacman, and a newer pacman version
available :
$ pacman -Su (or pacman -S <any targets>)
:: the following packages should be upgraded first :
    pacman
:: Do you want to cancel the current operation
:: and upgrade these packages now? [Y/n]

resolving dependencies...
looking for inter-conflicts...

Targets: pacman-x.y.z-t

Total Download Size:    x.xx MB
Total Installed Size:   x.xx MB

Proceed with installation? [Y/n] n

As Nagy previously noted, doing this check on any -S operations might look
intrusive, but it can be required.
For example, the case where you want to install a package with versioned
provisions, using a pacman version which didn't support that feature yet
(and there is already a newer pacman in sync db supporting it).

Signed-off-by: Chantry Xavier <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/doc/pacman.conf.5.txt b/doc/pacman.conf.5.txt
index 5514e2c0..eb9285c3 100644
--- a/doc/pacman.conf.5.txt
+++ b/doc/pacman.conf.5.txt
@@ -82,6 +82,12 @@ Options
 	Instructs pacman to ignore any upgrades for this package when performing
 	a '\--sysupgrade'.
 
+*SyncFirst =* package ...::
+	Instructs pacman to check for newer version of these packages before any
+	sync operation. The user will have the choice to either cancel the current
+	operation and upgrade these packages first or go on with the current operation.
+	This option is typically used with the 'pacman' package.
+
 *IgnoreGroup =* group ...::
 	Instructs pacman to ignore any upgrades for all packages in this
 	group when performing a '\--sysupgrade'.