Look in target-list first to resolve dependencies

This fixes a bug introduced by my previous changes which changes the
behavior of IgnorePkg/IgnoreGroup to allow the user to remove unresolvable
packages from the transaction.  The bug is that the target-list was no
longer being consulted first to resolve dependencies, which means that if
two packages in the sync database satisfied a dependency, and the user
explicitly requested one of those two packages in the sync, the other
package was still being pulled in.

A new test was added, sync993.py, to verify the desired behavior.

Signed-off-by: Bryan Ischo <bji-keyword-pacman.3644cb@www.ischo.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

lib/libalpm/deps.c

@@ -594,8 +594,8 @@ pmpkg_t *_alpm_resolvedep(pmdepend_t *dep, alpm_list_t *dbs,
  *         unmodified by this function
  */
 int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
-                      alpm_list_t **packages, alpm_list_t *remove,
+                      alpm_list_t *preferred, alpm_list_t **packages,
-                      alpm_list_t **data)
+                      alpm_list_t *remove, alpm_list_t **data)
 {
 	alpm_list_t *i, *j;
 	alpm_list_t *targ;
@@ -632,17 +632,21 @@ int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
 			if(_alpm_find_dep_satisfier(*packages, missdep)) {
 				continue;
 			}
-			/* find a satisfier package in the given repositories */
+			/* check if one of the packages in the [preferred] list already satisfies this dependency */
-			pmpkg_t *spkg = _alpm_resolvedep(missdep, dbs_sync, *packages, 0);
+			pmpkg_t *spkg = _alpm_find_dep_satisfier(preferred, missdep);
+			if(!spkg) {
+				/* find a satisfier package in the given repositories */
+				spkg = _alpm_resolvedep(missdep, dbs_sync, *packages, 0);
+			}
 			if(!spkg) {
 				pm_errno = PM_ERR_UNSATISFIED_DEPS;
 				char *missdepstring = alpm_dep_compute_string(missdep);
 				_alpm_log(PM_LOG_WARNING, _("cannot resolve \"%s\", a dependency of \"%s\"\n"),
-			                               missdepstring, tpkg->name);
+						missdepstring, tpkg->name);
 				free(missdepstring);
 				if(data) {
 					pmdepmissing_t *missd = _alpm_depmiss_new(miss->target,
-					                           miss->depend, miss->causingpkg);
+							miss->depend, miss->causingpkg);
 					if(missd) {
 						*data = alpm_list_add(*data, missd);
 					}
@@ -654,7 +658,7 @@ int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *pkg,
 				return(-1);
 			} else {
 				_alpm_log(PM_LOG_DEBUG, "pulling dependency %s (needed by %s)\n",
-					  alpm_pkg_get_name(spkg), alpm_pkg_get_name(tpkg));
+						alpm_pkg_get_name(spkg), alpm_pkg_get_name(tpkg));
 				*packages = alpm_list_add(*packages, spkg);
 			}
 		}

lib/libalpm/deps.h

@@ -49,7 +49,8 @@ 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,
-		      alpm_list_t **packages, alpm_list_t *remove, alpm_list_t **data);
+		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);
 pmdepend_t *_alpm_splitdep(const char *depstring);
 pmpkg_t *_alpm_find_dep_satisfier(alpm_list_t *pkgs, pmdepend_t *dep);

lib/libalpm/sync.c

@@ -348,6 +348,7 @@ static int compute_download_size(pmpkg_t *newpkg)
 int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync, alpm_list_t **data)
 {
 	alpm_list_t *deps = NULL;
+	alpm_list_t *preferred = NULL;
 	alpm_list_t *unresolvable = NULL;
 	alpm_list_t *remove = NULL; /* allow checkdeps usage with trans->packages */
 	alpm_list_t *i, *j;
@@ -370,19 +371,21 @@ int _alpm_sync_prepare(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t *dbs_sync
 		EVENT(trans, PM_TRANS_EVT_RESOLVEDEPS_START, NULL, NULL);
 		_alpm_log(PM_LOG_DEBUG, "resolving target's dependencies\n");
 
-		/* build remove list for resolvedeps */
+		/* build remove list and preferred list for resolvedeps */
 		for(i = trans->packages; i; i = i->next) {
 			pmpkg_t *spkg = i->data;
 			for(j = spkg->removes; j; j = j->next) {
 				remove = alpm_list_add(remove, j->data);
 			}
+			preferred = alpm_list_add(preferred, spkg);
 		}
 
 		/* 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->packages; i; i = i->next) {
 			pmpkg_t *pkg = i->data;
-			if(_alpm_resolvedeps(db_local, dbs_sync, pkg, &resolved, remove, data) == -1) {
+			if(_alpm_resolvedeps(db_local, dbs_sync, pkg, preferred,
+						&resolved, remove, data) == -1) {
 				unresolvable = alpm_list_add(unresolvable, pkg);
 			}
 			/* Else, [resolved] now additionally contains [pkg] and all of its

pactest/tests/sync993.py

@@ -0,0 +1,20 @@
+self.description = "Choose a dependency satisfier (target-list vs. database)"
+
+sp1 = pmpkg("pkg1")
+sp1.depends = ["dep"]
+
+sp2 = pmpkg("pkg2")
+sp2.provides = ["dep"]
+
+sp3 = pmpkg("pkg3")
+sp3.provides = ["dep"]
+
+for p in sp1, sp2, sp3:
+        self.addpkg2db("sync", p)
+
+self.args = "-S pkg1 pkg3"
+
+self.addrule("PACMAN_RETCODE=0")
+self.addrule("PKG_EXIST=pkg1")
+self.addrule("!PKG_EXIST=pkg2")
+self.addrule("PKG_EXIST=pkg3")