Partial fix for the phonon/qt issue

This patch fixes the phonon/qt issue, if all to-be-upgraded packages are
explicit targets (ie. only not-yet-installed packages are pulled by
resolvedeps). This condition covers the most common situations, for example
it should hold with every -Su operation.

After this patch sync405.py passes, but sync406.py doesn't.

The work is inspired by the patch of Henning Garus, thanks for his work:
http://mailman.archlinux.org/pipermail/pacman-dev/2010-February/010429.html
(I moved the alpm_list_diff computation to sync.c in order to compute it
only once.)

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

lib/libalpm/deps.c

@@ -578,7 +578,7 @@ pmpkg_t *_alpm_resolvedep(pmdepend_t *dep, alpm_list_t *dbs,
 /* Computes resolvable dependencies for a given package and adds that package
  * and those resolvable dependencies to a list.
  *
- * @param local is the local database
+ * @param localpkgs is the list of local packages
  * @param dbs_sync are the sync databases
  * @param pkg is the package to resolve
  * @param packages is a pointer to a list of packages which will be
@@ -594,7 +594,7 @@ pmpkg_t *_alpm_resolvedep(pmdepend_t *dep, alpm_list_t *dbs,
  *         unresolvable dependency, in which case the [*packages] list will be
  *         unmodified by this function
  */
-int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
+int _alpm_resolvedeps(alpm_list_t *localpkgs, alpm_list_t *dbs_sync, pmpkg_t *pkg,
                       alpm_list_t *preferred, alpm_list_t **packages,
                       alpm_list_t *remove, alpm_list_t **data)
 {
@@ -605,10 +605,6 @@ int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
 
 	ALPM_LOG_FUNC;
 
-	if(local == NULL) {
-		return(-1);
-	}
-
 	if(_alpm_pkg_find(*packages, pkg->name) != NULL) {
 		return(0);
 	}
@@ -624,7 +620,7 @@ int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
 	for(i = alpm_list_last(*packages); i; i = i->next) {
 		pmpkg_t *tpkg = i->data;
 		targ = alpm_list_add(NULL, tpkg);
-		deps = alpm_checkdeps(_alpm_db_get_pkgcache(local), 0, remove, targ);
+		deps = alpm_checkdeps(localpkgs, 0, remove, targ);
 		alpm_list_free(targ);
 		for(j = deps; j; j = j->next) {
 			pmdepmissing_t *miss = j->data;

lib/libalpm/deps.h

@@ -49,7 +49,7 @@ void _alpm_depmiss_free(pmdepmissing_t *miss);
 alpm_list_t *_alpm_sortbydeps(alpm_list_t *targets, int reverse);
 void _alpm_recursedeps(pmdb_t *db, alpm_list_t *targs, int include_explicit);
 pmpkg_t *_alpm_resolvedep(pmdepend_t *dep, alpm_list_t *dbs, alpm_list_t *excluding, int prompt);
-int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
+int _alpm_resolvedeps(alpm_list_t *localpkgs, alpm_list_t *dbs_sync, pmpkg_t *pkg,
 		alpm_list_t *preferred, alpm_list_t **packages, alpm_list_t *remove,
 		alpm_list_t **data);
 int _alpm_dep_edge(pmpkg_t *pkg1, pmpkg_t *pkg2);

lib/libalpm/sync.c

@@ -431,17 +431,21 @@ int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync
 			}
 		}
 
+		/* Compute the fake local database for resolvedeps (partial fix for the phonon/qt issue) */
+		alpm_list_t *localpkgs = alpm_list_diff(_alpm_db_get_pkgcache(db_local), trans->add, _alpm_pkg_cmp);
+
 		/* Resolve packages in the transaction one at a time, in addtion
 		   building up a list of packages which could not be resolved. */
 		for(i = trans->add; i; i = i->next) {
 			pmpkg_t *pkg = i->data;
-			if(_alpm_resolvedeps(db_local, dbs_sync, pkg, trans->add,
+			if(_alpm_resolvedeps(localpkgs, dbs_sync, pkg, trans->add,
 						&resolved, remove, data) == -1) {
 				unresolvable = alpm_list_add(unresolvable, pkg);
 			}
 			/* Else, [resolved] now additionally contains [pkg] and all of its
 			   dependencies not already on the list */
 		}
+		alpm_list_free(localpkgs);
 
 		/* If there were unresolvable top-level packages, prompt the user to
 		   see if they'd like to ignore them rather than failing the sync */

pactest/tests/sync405.py

@@ -22,5 +22,3 @@ self.addrule("PKG_EXIST=kdelibs")
 self.addrule("PKG_EXIST=qt")
 self.addrule("PKG_EXIST=phonon")
 self.addrule("PKG_VERSION=qt|4.6.1-1")
-
-self.expectfailure = True