Fix segfault with sparse encoding
The native code that underlies `Resources#getIdentifier()` did not take
sparse encoding into account when calculating offsets, resulting in
either garbage or SEGV_MAPERR whenever a resource is first encountered
in a sparsely encoded configuration.
Bug: 197976367
Test: atest libandroidfw_tests --host
Change-Id: Ib7550fe2e05005550f59129a06be5712b74bc9c8
diff --git a/libs/androidfw/tests/LoadedArsc_test.cpp b/libs/androidfw/tests/LoadedArsc_test.cpp
index f356c8130..d214e2d 100644
--- a/libs/androidfw/tests/LoadedArsc_test.cpp
+++ b/libs/androidfw/tests/LoadedArsc_test.cpp
@@ -95,6 +95,38 @@
ASSERT_TRUE(LoadedPackage::GetEntry(type.type, entry_index).has_value());
}
+TEST(LoadedArscTest, FindSparseEntryApp) {
+ std::string contents;
+ ASSERT_TRUE(ReadFileFromZipToString(GetTestDataPath() + "/sparse/sparse.apk", "resources.arsc",
+ &contents));
+
+ std::unique_ptr<const LoadedArsc> loaded_arsc = LoadedArsc::Load(contents.data(),
+ contents.length());
+ ASSERT_THAT(loaded_arsc, NotNull());
+
+ const LoadedPackage* package =
+ loaded_arsc->GetPackageById(get_package_id(sparse::R::string::only_v26));
+ ASSERT_THAT(package, NotNull());
+
+ const uint8_t type_index = get_type_id(sparse::R::string::only_v26) - 1;
+ const uint16_t entry_index = get_entry_id(sparse::R::string::only_v26);
+
+ const TypeSpec* type_spec = package->GetTypeSpecByTypeIndex(type_index);
+ ASSERT_THAT(type_spec, NotNull());
+ ASSERT_THAT(type_spec->type_entries.size(), Ge(1u));
+
+ // Ensure that AAPT2 sparsely encoded the v26 config as expected.
+ auto type_entry = std::find_if(
+ type_spec->type_entries.begin(), type_spec->type_entries.end(),
+ [](const TypeSpec::TypeEntry& x) { return x.config.sdkVersion == 26; });
+ ASSERT_NE(type_entry, type_spec->type_entries.end());
+ ASSERT_NE(type_entry->type->flags & ResTable_type::FLAG_SPARSE, 0);
+
+ // Test fetching a resource with only sparsely encoded configs by name.
+ auto id = package->FindEntryByName(u"string", u"only_v26");
+ ASSERT_EQ(id.value(), fix_package_id(sparse::R::string::only_v26, 0));
+}
+
TEST(LoadedArscTest, LoadSharedLibrary) {
std::string contents;
ASSERT_TRUE(ReadFileFromZipToString(GetTestDataPath() + "/lib_one/lib_one.apk", "resources.arsc",