Show 'Required By' in -Sii output

Just as we do in -Qi, we can compute required by information for sync
database packages. The behavior seems sane; for a given package, the -Sii
required by will show all packages in *any* sync database that require it.

Implements FS#16244.

Signed-off-by: Dan McGee <dan@archlinux.org>

lib/libalpm/package.c

@@ -555,6 +555,21 @@ int SYMEXPORT alpm_pkg_has_scriptlet(pmpkg_t *pkg)
 	return pkg->scriptlet;
 }
 
+static void find_requiredby(pmpkg_t *pkg, pmdb_t *db, alpm_list_t **reqs)
+{
+	const alpm_list_t *i;
+	for(i = _alpm_db_get_pkgcache(db); i; i = i->next) {
+		if(!i->data) {
+			continue;
+		}
+		pmpkg_t *cachepkg = i->data;
+		if(_alpm_dep_edge(cachepkg, pkg)) {
+			const char *cachepkgname = cachepkg->name;
+			*reqs = alpm_list_add(*reqs, strdup(cachepkgname));
+		}
+	}
+}
+
 /**
  * @brief Compute the packages requiring a given package.
  * @param pkg a package
@@ -564,16 +579,23 @@ alpm_list_t SYMEXPORT *alpm_pkg_compute_requiredby(pmpkg_t *pkg)
 {
 	const alpm_list_t *i;
 	alpm_list_t *reqs = NULL;
+	pmdb_t *db;
 
-	pmdb_t *localdb = alpm_option_get_localdb();
-	for(i = _alpm_db_get_pkgcache(localdb); i; i = i->next) {
-		if(!i->data) {
-			continue;
-		}
-		pmpkg_t *cachepkg = i->data;
-		if(_alpm_dep_edge(cachepkg, pkg)) {
-			const char *cachepkgname = cachepkg->name;
-			reqs = alpm_list_add(reqs, strdup(cachepkgname));
+	if(pkg->origin == PKG_FROM_FILE) {
+		/* The sane option; search locally for things that require this. */
+		db = alpm_option_get_localdb();
+		find_requiredby(pkg, db, &reqs);
+	} else {
+		/* We have a DB package. if it is a local package, then we should
+		 * only search the local DB; else search all known sync databases. */
+		db = pkg->origin_data.db;
+		if(db->is_local) {
+			find_requiredby(pkg, db, &reqs);
+		} else {
+			for(i = handle->dbs_sync; i; i = i->next) {
+				db = i->data;
+				find_requiredby(pkg, db, &reqs);
+			}
 		}
 	}
 	return(reqs);

src/pacman/package.c

@@ -38,7 +38,9 @@
 
 /* Display the content of a package
  *
- * level: <0 - sync package [-Si]
+ * levels:
+ *       <-1 - sync package, extra information (required by) [-Sii]
+ *        -1 - sync package, normal level [-Si]
  *        =0 - file query [-Qip]
  *         1 - localdb query, normal level [-Qi]
  *        >1 - localdb query, extra information (backup files) [-Qii]
@@ -83,7 +85,7 @@ void dump_pkg_full(pmpkg_t *pkg, int level)
 		depstrings = alpm_list_add(depstrings, alpm_dep_compute_string(dep));
 	}
 
-	if(level>0) {
+	if(level > 0 || level < -1) {
 		/* compute this here so we don't get a pause in the middle of output */
 		requiredby = alpm_pkg_compute_requiredby(pkg);
 	}
@@ -97,10 +99,8 @@ void dump_pkg_full(pmpkg_t *pkg, int level)
 	list_display(_("Provides       :"), alpm_pkg_get_provides(pkg));
 	list_display(_("Depends On     :"), depstrings);
 	list_display_linebreak(_("Optional Deps  :"), alpm_pkg_get_optdepends(pkg));
-	/* Only applicable if installed */
-	if(level > 0) {
+	if(level > 0 || level < -1) {
 		list_display(_("Required By    :"), requiredby);
-		FREELIST(requiredby);
 	}
 	list_display(_("Conflicts With :"), alpm_pkg_get_conflicts(pkg));
 	list_display(_("Replaces       :"), alpm_pkg_get_replaces(pkg));
@@ -142,17 +142,19 @@ void dump_pkg_full(pmpkg_t *pkg, int level)
 	printf("\n");
 
 	FREELIST(depstrings);
+	FREELIST(requiredby);
 }
 
 /* Display the content of a sync package
  */
-void dump_pkg_sync(pmpkg_t *pkg, const char *treename)
+void dump_pkg_sync(pmpkg_t *pkg, const char *treename, int level)
 {
 	if(pkg == NULL) {
 		return;
 	}
 	string_display(_("Repository     :"), treename);
-	dump_pkg_full(pkg, -1);
+	/* invert the level since we are a sync package */
+	dump_pkg_full(pkg, -level);
 }
 
 /* Display list of backup files and their modification states

src/pacman/package.h

@@ -23,7 +23,7 @@
 #include <alpm.h>
 
 void dump_pkg_full(pmpkg_t *pkg, int level);
-void dump_pkg_sync(pmpkg_t *pkg, const char *treename);
+void dump_pkg_sync(pmpkg_t *pkg, const char *treename, int level);
 
 void dump_pkg_backups(pmpkg_t *pkg);
 void dump_pkg_files(pmpkg_t *pkg, int quiet);

src/pacman/sync.c

@@ -453,7 +453,7 @@ static int sync_info(alpm_list_t *syncs, alpm_list_t *targets)
 					pmpkg_t *pkg = alpm_list_getdata(k);
 
 					if(strcmp(alpm_pkg_get_name(pkg), pkgstr) == 0) {
-						dump_pkg_sync(pkg, alpm_db_get_name(db));
+						dump_pkg_sync(pkg, alpm_db_get_name(db), config->op_s_info);
 						foundpkg = 1;
 						break;
 					}
@@ -474,7 +474,7 @@ static int sync_info(alpm_list_t *syncs, alpm_list_t *targets)
 						pmpkg_t *pkg = alpm_list_getdata(k);
 
 						if(strcmp(alpm_pkg_get_name(pkg), pkgstr) == 0) {
-							dump_pkg_sync(pkg, alpm_db_get_name(db));
+							dump_pkg_sync(pkg, alpm_db_get_name(db), config->op_s_info);
 							foundpkg = 1;
 							break;
 						}
@@ -492,7 +492,7 @@ static int sync_info(alpm_list_t *syncs, alpm_list_t *targets)
 			pmdb_t *db = alpm_list_getdata(i);
 
 			for(j = alpm_db_get_pkgcache(db); j; j = alpm_list_next(j)) {
-				dump_pkg_sync(alpm_list_getdata(j), alpm_db_get_name(db));
+				dump_pkg_sync(alpm_list_getdata(j), alpm_db_get_name(db), config->op_s_info);
 			}
 		}
 	}