Introduce -Suu

If the user switches from unstable repo to a stable one, it is quite hard to
sync its system with the new repo (the user will see many "Local is newer
than stable" messages, nothing more). That's why I introduced -Suu, which
treats a sync package like an upgrade, iff the package version doesn't match
with the local one's.

I added a new pactest (sync104.py) to test this, and I updated the
documentation of -Su.

Signed-off-by: Nagy Gabor <ngaba@bibl.u-szeged.hu>
[Dan: slight doc reword]
Signed-off-by: Dan McGee <dan@archlinux.org>

doc/pacman.8.txt

@@ -327,7 +327,10 @@ linkman:pacman.conf[5].
 	report of all packages to upgrade will be presented and  the operation
 	will not proceed without user confirmation. Dependencies are
 	automatically resolved at this level and will be installed/upgraded if
-	necessary.
+	necessary. Pass this option twice to enable package downgrade; in this
+	case pacman will select sync packages whose version does not match with
+	the local version. This can be useful when the user switches from a testing
+	repo to a stable one.
 
 *-w, \--downloadonly*::
 	Retrieve all packages from the server, but do not install/upgrade

lib/libalpm/alpm.h

@@ -397,7 +397,7 @@ alpm_list_t * alpm_trans_get_pkgs();
 int alpm_trans_init(pmtranstype_t type, pmtransflag_t flags,
                     alpm_trans_cb_event cb_event, alpm_trans_cb_conv conv,
                     alpm_trans_cb_progress cb_progress);
-int alpm_trans_sysupgrade(void);
+int alpm_trans_sysupgrade(int enable_downgrade);
 int alpm_trans_addtarget(char *target);
 int alpm_trans_prepare(alpm_list_t **data);
 int alpm_trans_commit(alpm_list_t **data);

lib/libalpm/sync.c

@@ -80,7 +80,7 @@ pmpkg_t SYMEXPORT *alpm_sync_newversion(pmpkg_t *pkg, alpm_list_t *dbs_sync)
 	return(NULL);
 }
 
-int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync)
+int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, int enable_downgrade)
 {
 	alpm_list_t *i, *j, *k;
 
@@ -116,8 +116,20 @@ int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_s
 						trans->packages = alpm_list_add(trans->packages, spkg);
 					}
 				} else if(cmp < 0) {
-					_alpm_log(PM_LOG_WARNING, _("%s: local (%s) is newer than %s (%s)\n"),
-							lpkg->name, lpkg->version, sdb->treename, spkg->version);
+					if(enable_downgrade) {
+						/* check IgnorePkg/IgnoreGroup */
+						if(_alpm_pkg_should_ignore(spkg) || _alpm_pkg_should_ignore(lpkg)) {
+							_alpm_log(PM_LOG_WARNING, _("%s: ignoring package downgrade (%s => %s)\n"),
+											lpkg->name, lpkg->version, spkg->version);
+						} else {
+							_alpm_log(PM_LOG_WARNING, _("%s: downgrading from version %s to version %s\n"),
+											lpkg->name, lpkg->version, spkg->version);
+							trans->packages = alpm_list_add(trans->packages, spkg);
+						}
+					} else {
+						_alpm_log(PM_LOG_WARNING, _("%s: local (%s) is newer than %s (%s)\n"),
+								lpkg->name, lpkg->version, sdb->treename, spkg->version);
+					}
 				}
 				break; /* jump to next local package */
 			} else { /* 2. search for replacers in sdb */

lib/libalpm/sync.h

@@ -24,7 +24,7 @@
 
 #include "alpm.h"
 
-int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync);
+int _alpm_sync_sysupgrade(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, int enable_downgrade);
 
 int _alpm_sync_addtarget(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, char *name);
 int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, alpm_list_t **data);

lib/libalpm/trans.c

@@ -89,7 +89,7 @@ int SYMEXPORT alpm_trans_init(pmtranstype_t type, pmtransflag_t flags,
 /** Search for packages to upgrade and add them to the transaction.
  * @return 0 on success, -1 on error (pm_errno is set accordingly)
  */
-int SYMEXPORT alpm_trans_sysupgrade()
+int SYMEXPORT alpm_trans_sysupgrade(int enable_downgrade)
 {
 	pmtrans_t *trans;
 
@@ -102,7 +102,7 @@ int SYMEXPORT alpm_trans_sysupgrade()
 	ASSERT(trans->state == STATE_INITIALIZED, RET_ERR(PM_ERR_TRANS_NOT_INITIALIZED, -1));
 	ASSERT(trans->type == PM_TRANS_TYPE_SYNC, RET_ERR(PM_ERR_TRANS_TYPE, -1));
 
-	return(_alpm_sync_sysupgrade(trans, handle->db_local, handle->dbs_sync));
+	return(_alpm_sync_sysupgrade(trans, handle->db_local, handle->dbs_sync, enable_downgrade));
 }
 
 /** Add a target to the transaction.

pactest/tests/sync104.py

@@ -0,0 +1,12 @@
+self.description = "-Suu"
+
+sp = pmpkg("dummy", "0.9-1")
+lp = pmpkg("dummy", "1.0-1")
+
+self.addpkg2db("sync", sp)
+self.addpkg2db("local", lp)
+
+self.args = "-Suu"
+
+self.addrule("PACMAN_RETCODE=0")
+self.addrule("PKG_VERSION=dummy|0.9-1")

src/pacman/pacman.c

@@ -130,7 +130,7 @@ static void usage(int op, const char * const myname)
 			printf(_("  -l, --list <repo>    view a list of packages in a repo\n"));
 			printf(_("  -p, --print-uris     print out URIs for given packages and their dependencies\n"));
 			printf(_("  -s, --search <regex> search remote repositories for matching strings\n"));
-			printf(_("  -u, --sysupgrade     upgrade all packages that are out of date\n"));
+			printf(_("  -u, --sysupgrade     upgrade all outdated packages (-uu enables downgrade)\n"));
 			printf(_("  -w, --downloadonly   download packages but do not install/upgrade anything\n"));
 			printf(_("  -y, --refresh        download fresh package databases from the server\n"));
 			printf(_("      --needed         don't reinstall up to date packages\n"));
@@ -508,7 +508,7 @@ static int parseargs(int argc, char *argv[])
 				config->op_q_unrequired = 1;
 				break;
 			case 'u':
-				config->op_s_upgrade = 1;
+				(config->op_s_upgrade)++;
 				config->op_q_upgrade = 1;
 				config->flags |= PM_TRANS_FLAG_UNNEEDED;
 				break;

src/pacman/sync.c

@@ -563,7 +563,7 @@ static int sync_trans(alpm_list_t *targets)
 	if(config->op_s_upgrade) {
 		printf(_(":: Starting full system upgrade...\n"));
 		alpm_logaction("starting full system upgrade\n");
-		if(alpm_trans_sysupgrade() == -1) {
+		if(alpm_trans_sysupgrade(config->op_s_upgrade >= 2) == -1) {
 			pm_fprintf(stderr, PM_LOG_ERROR, "%s\n", alpm_strerrorlast());
 			retval = 1;
 			goto cleanup;