alpm_list_add == alpm_list_add_last

It's time to define that alpm_list_add(list, foo) adds 'foo' to the end of
'list' and returns with 'list', because:
1. list is a list, not a set.
2. sortbydeps _needs_ an alpm_list_add definition to work properly.

As a first step, I used this definition in recursedeps.

Signed-off-by: Nagy Gabor <ngaba@bibl.u-szeged.hu>
[Dan: punctuation cleanup in commit message and code comments, added comment
to alpm_list_add]
Signed-off-by: Dan McGee <dan@archlinux.org>

4 files changed, 24 insertions, 33 deletions

diff --git a/lib/libalpm/alpm_list.c b/lib/libalpm/alpm_list.c
index 465c1a8f..774d1dbe 100644
--- a/lib/libalpm/alpm_list.c
+++ b/lib/libalpm/alpm_list.c
@@ -98,7 +98,7 @@ void SYMEXPORT alpm_list_free_inner(alpm_list_t *list, alpm_list_fn_free fn)
 /* Mutators */
 
 /**
- * @brief Add a new item to the list.
+ * @brief Add a new item to the end of the list.
  *
  * @param list the list to add to
  * @param data the new item to be added to the list
diff --git a/lib/libalpm/deps.c b/lib/libalpm/deps.c
index b551681a..63775d20 100644
--- a/lib/libalpm/deps.c
+++ b/lib/libalpm/deps.c
@@ -596,12 +596,13 @@ static int can_remove_package(pmdb_t *db, pmpkg_t *pkg, alpm_list_t *targets,
  * @brief Adds unneeded dependencies to an existing list of packages.
  * By unneeded, we mean dependencies that are only required by packages in the
  * target list, so they can be safely removed.
+ * If the input list was topo sorted, the output list will be topo sorted too.
  *
  * @param db package database to do dependency tracing in
  * @param *targs pointer to a list of packages
  * @param include_explicit if 0, explicitly installed packages are not included
  */
-void _alpm_recursedeps(pmdb_t *db, alpm_list_t **targs, int include_explicit)
+void _alpm_recursedeps(pmdb_t *db, alpm_list_t *targs, int include_explicit)
 {
 	alpm_list_t *i, *j, *k;
 
@@ -611,34 +612,24 @@ void _alpm_recursedeps(pmdb_t *db, alpm_list_t **targs, int include_explicit)
 		return;
 	}
 
-	/* TODO: the while loop should be removed if we can assume
-	 * that alpm_list_add (or another function) adds to the end of the list,
-	 * and that the target list is topo sorted (by _alpm_sortbydeps()).
-	 */
-	int ready = 0;
-	while(!ready) {
-		ready = 1;
-		for(i = *targs; i; i = i->next) {
-			pmpkg_t *pkg = i->data;
-			for(j = alpm_pkg_get_depends(pkg); j; j = j->next) {
-				pmdepend_t *depend = alpm_splitdep(j->data);
-				if(depend == NULL) {
-					continue;
-				}
-				for(k = _alpm_db_get_pkgcache(db); k; k = k->next) {
-					pmpkg_t *deppkg = k->data;
-					if(alpm_depcmp(deppkg,depend)
-							&& can_remove_package(db, deppkg, *targs, include_explicit)) {
-						_alpm_log(PM_LOG_DEBUG, "adding '%s' to the targets\n",
-								alpm_pkg_get_name(deppkg));
-
+	for(i = targs; i; i = i->next) {
+		pmpkg_t *pkg = i->data;
+		for(j = alpm_pkg_get_depends(pkg); j; j = j->next) {
+			pmdepend_t *depend = alpm_splitdep(j->data);
+			if(depend == NULL) {
+				continue;
+			}
+			for(k = _alpm_db_get_pkgcache(db); k; k = k->next) {
+				pmpkg_t *deppkg = k->data;
+				if(alpm_depcmp(deppkg,depend)
+						&& can_remove_package(db, deppkg, targs, include_explicit)) {
+					_alpm_log(PM_LOG_DEBUG, "adding '%s' to the targets\n",
+							alpm_pkg_get_name(deppkg));
 						/* add it to the target list */
-						*targs = alpm_list_add(*targs, _alpm_pkg_dup(deppkg));
-						ready = 0;
-					}
+					targs = alpm_list_add(targs, _alpm_pkg_dup(deppkg));
 				}
-				FREE(depend);
 			}
+			FREE(depend);
 		}
 	}
 }
diff --git a/lib/libalpm/deps.h b/lib/libalpm/deps.h
index 59b26307..f11a8d88 100644
--- a/lib/libalpm/deps.h
+++ b/lib/libalpm/deps.h
@@ -58,7 +58,7 @@ int _alpm_depmiss_isin(pmdepmissing_t *needle, alpm_list_t *haystack);
 alpm_list_t *_alpm_sortbydeps(alpm_list_t *targets, pmtranstype_t mode);
 alpm_list_t *_alpm_checkdeps(pmdb_t *db, pmtranstype_t op,
                              alpm_list_t *packages);
-void _alpm_recursedeps(pmdb_t *db, alpm_list_t **targs, int include_explicit);
+void _alpm_recursedeps(pmdb_t *db, alpm_list_t *targs, int include_explicit);
 int _alpm_resolvedeps(pmdb_t *local, alpm_list_t *dbs_sync, pmpkg_t *syncpkg,
                       alpm_list_t **list, pmtrans_t *trans, alpm_list_t **data);
 
diff --git a/lib/libalpm/remove.c b/lib/libalpm/remove.c
index c4e44398..86cfee68 100644
--- a/lib/libalpm/remove.c
+++ b/lib/libalpm/remove.c
@@ -137,11 +137,6 @@ int _alpm_remove_prepare(pmtrans_t *trans, pmdb_t *db, alpm_list_t **data)
 		}
 	}
 
-	if(trans->flags & PM_TRANS_FLAG_RECURSE) {
-		_alpm_log(PM_LOG_DEBUG, "finding removable dependencies\n");
-		_alpm_recursedeps(db, &trans->packages, 0);
-	}
-
 	/* re-order w.r.t. dependencies */ 
 	_alpm_log(PM_LOG_DEBUG, "sorting by dependencies\n");
 	lp = _alpm_sortbydeps(trans->packages, PM_TRANS_TYPE_REMOVE);
@@ -149,6 +144,11 @@ int _alpm_remove_prepare(pmtrans_t *trans, pmdb_t *db, alpm_list_t **data)
 	alpm_list_free(trans->packages);
 	trans->packages = lp;
 
+	if(trans->flags & PM_TRANS_FLAG_RECURSE) {
+		_alpm_log(PM_LOG_DEBUG, "finding removable dependencies\n");
+		_alpm_recursedeps(db, trans->packages, 0);
+	}
+
 	EVENT(trans, PM_TRANS_EVT_CHECKDEPS_DONE, NULL, NULL);
 
 	return(0);