solver: fix installation of non-repository packages during tmpfs boot

allow packages in the cache's installed to be selected for installation
by the solver. add test case for the issue.

src/apk_package.h

@@ -114,9 +114,10 @@ struct apk_package {
 	struct apk_dependency_array *depends, *install_if, *provides;
 	size_t installed_size, size;
 	time_t build_time;
+	unsigned repos : APK_MAX_REPOS;
 	unsigned marked : 1;
 	unsigned uninstallable : 1;
-	unsigned repos : APK_MAX_REPOS;
+	unsigned cached_non_repository : 1;
 	struct apk_checksum csum;
 };
 APK_ARRAY(apk_package_array, struct apk_package *);

src/commit.c

@@ -379,6 +379,9 @@ static void print_pinning_errors(struct print_state *ps, struct apk_package *pkg
 	if (!(pkg->repos & db->available_repos)) {
 		label_start(ps, "masked in:");
 		apk_print_indented_fmt(&ps->i, "--no-network");
+	} else if (pkg->repos == BIT(APK_REPOSITORY_CACHED)) {
+		label_start(ps, "masked in:");
+		apk_print_indented_fmt(&ps->i, "cache");
 	} else {
 		if (pkg->repos & apk_db_get_pinning_mask_repos(db, APK_DEFAULT_PINNING_MASK | BIT(tag)))
 			return;

src/database.c

@@ -760,6 +760,8 @@ int apk_db_index_read(struct apk_database *db, struct apk_bstream *bs, int repo)
 
 			if (repo >= 0) {
 				pkg->repos |= BIT(repo);
+			} else if (repo == -2) {
+				pkg->cached_non_repository = 1;
 			} else if (repo == -1 && ipkg == NULL) {
 				/* Installed package without files */
 				ipkg = apk_pkg_install(db, pkg);

src/solver.c

@@ -197,6 +197,7 @@ static void discover_name(struct apk_solver_state *ss, struct apk_name *name)
 		 * or it's a 'virtual' package with install_size zero */
 		pkg->ss.pkg_selectable =
 			(pkg->repos & db->available_repos) ||
+			pkg->cached_non_repository ||
 			pkg->ipkg;
 
 		/* Prune install_if packages that are no longer available,
@@ -212,8 +213,11 @@ static void discover_name(struct apk_solver_state *ss, struct apk_name *name)
 		pkg->ss.tag_preferred =
 			(pkg->filename != NULL) ||
 			(pkg->installed_size == 0) ||
-			!!(repos & ss->default_repos);
-		pkg->ss.tag_ok = pkg->ss.tag_preferred || pkg->ipkg;
+			(repos & ss->default_repos);
+		pkg->ss.tag_ok =
+			pkg->ss.tag_preferred ||
+			pkg->cached_non_repository ||
+			pkg->ipkg;
 
 		foreach_array_item(dep, pkg->depends) {
 			discover_name(ss, dep->name);

test/basic16.test

+@ARGS
+--no-network
+--test-repo !basic.repo
+add a
+@EXPECT
+(1/2) Installing b (2)
+(2/2) Installing a (2)
+OK: 0 MiB in 0 packages