AAPT2: Fix R.java for styleable in different package

When generating the R.java file, attributes of styleables do not always
have package names on them. This caused a problem where when an apk
that was previously linked and that also contained a declare-styleable
is linked again to an AndroidManifest.xml with a different package name,
styleable attributes' resource symbols could not be looked up correctly.

This change does not rename the resources but makes sure that the java
generator finds the attribute symbols correctly.

Bug: 110877419
Test: Created a test in aapt2_tests and verified correct behavior of
repro example from bug

Change-Id: Ib99d84cbe44dadca86603bc610ad3f4e09e3fb11

2 files changed, 63 insertions, 3 deletions

diff --git a/tools/aapt2/java/JavaClassGenerator.cpp b/tools/aapt2/java/JavaClassGenerator.cpp
index db1561e17f16..d1a70a75a44e 100644
--- a/tools/aapt2/java/JavaClassGenerator.cpp
+++ b/tools/aapt2/java/JavaClassGenerator.cpp
@@ -256,9 +256,20 @@ void JavaClassGenerator::ProcessStyleable(const ResourceNameRef& name, const Res
     styleable_attr.field_name =
         TransformNestedAttr(attr.name.value(), array_field_name, package_name_to_generate);
 
+    Reference ref = attr;
+    if (attr.name.value().package.empty()) {
+
+      // If the resource does not have a package name, set the package to the unmangled package name
+      // of the styleable declaration because attributes without package names would have been
+      // declared in the same package as the styleable.
+      ref.name = ResourceName(package_name_to_generate, ref.name.value().type,
+                              ref.name.value().entry);
+    }
+
     // Look up the symbol so that we can write out in the comments what are possible legal values
     // for this attribute.
-    const SymbolTable::Symbol* symbol = context_->GetExternalSymbols()->FindByReference(attr);
+    const SymbolTable::Symbol* symbol = context_->GetExternalSymbols()->FindByReference(ref);
+
     if (symbol && symbol->attribute) {
       // Copy the symbol data structure because the returned instance can be destroyed.
       styleable_attr.symbol = *symbol;
@@ -303,7 +314,7 @@ void JavaClassGenerator::ProcessStyleable(const ResourceNameRef& name, const Res
       const ResourceName& attr_name = entry.attr_ref->name.value();
       styleable_comment << "<tr><td><code>{@link #" << entry.field_name << " "
                         << (!attr_name.package.empty() ? attr_name.package
-                                                       : context_->GetCompilationPackage())
+                                                       : package_name_to_generate)
                         << ":" << attr_name.entry << "}</code></td>";
 
       // Only use the comment up until the first '.'. This is to stay compatible with
@@ -374,7 +385,7 @@ void JavaClassGenerator::ProcessStyleable(const ResourceNameRef& name, const Res
 
       StringPiece package_name = attr_name.package;
       if (package_name.empty()) {
-        package_name = context_->GetCompilationPackage();
+        package_name = package_name_to_generate;
       }
 
       std::unique_ptr<IntMember> index_member =
diff --git a/tools/aapt2/java/JavaClassGenerator_test.cpp b/tools/aapt2/java/JavaClassGenerator_test.cpp
index 10a97d84f59d..fa208be120ed 100644
--- a/tools/aapt2/java/JavaClassGenerator_test.cpp
+++ b/tools/aapt2/java/JavaClassGenerator_test.cpp
@@ -107,6 +107,55 @@ TEST(JavaClassGeneratorTest, CorrectPackageNameIsUsed) {
   EXPECT_THAT(output, Not(HasSubstr("com_foo$two")));
 }
 
+TEST(JavaClassGeneratorTest, StyleableAttributesWithDifferentPackageName) {
+  std::unique_ptr<ResourceTable> table =
+      test::ResourceTableBuilder()
+          .SetPackageId("android", 0x01)
+          .SetPackageId("app", 0x7f)
+          .AddValue("app:attr/foo", ResourceId(0x7f010000),
+                    test::AttributeBuilder().Build())
+          .AddValue("app:attr/bar", ResourceId(0x7f010001),
+                    test::AttributeBuilder().Build())
+          .AddValue("android:attr/baz", ResourceId(0x01010000),
+                    test::AttributeBuilder().Build())
+          .AddValue("app:styleable/MyStyleable", ResourceId(0x7f030000),
+                    test::StyleableBuilder()
+                        .AddItem("app:attr/foo", ResourceId(0x7f010000))
+                        .AddItem("attr/bar", ResourceId(0x7f010001))
+                        .AddItem("android:attr/baz", ResourceId(0x01010000))
+                        .Build())
+          .Build();
+
+  std::unique_ptr<IAaptContext> context =
+      test::ContextBuilder()
+          .AddSymbolSource(util::make_unique<ResourceTableSymbolSource>(table.get()))
+          .SetNameManglerPolicy(NameManglerPolicy{"custom"})
+          .SetCompilationPackage("custom")
+          .Build();
+  JavaClassGenerator generator(context.get(), table.get(), {});
+
+  std::string output;
+  StringOutputStream out(&output);
+  EXPECT_TRUE(generator.Generate("app", &out));
+  out.Flush();
+
+  EXPECT_THAT(output, Not(HasSubstr("public static final int baz=0x01010000;")));
+  EXPECT_THAT(output, HasSubstr("public static final int foo=0x7f010000;"));
+  EXPECT_THAT(output, HasSubstr("public static final int bar=0x7f010001;"));
+
+  EXPECT_THAT(output, HasSubstr("public static final int MyStyleable_android_baz=0;"));
+  EXPECT_THAT(output, HasSubstr("public static final int MyStyleable_foo=1;"));
+  EXPECT_THAT(output, HasSubstr("public static final int MyStyleable_bar=2;"));
+
+  EXPECT_THAT(output, HasSubstr("@link #MyStyleable_android_baz android:baz"));
+  EXPECT_THAT(output, HasSubstr("@link #MyStyleable_foo app:foo"));
+  EXPECT_THAT(output, HasSubstr("@link #MyStyleable_bar app:bar"));
+
+  EXPECT_THAT(output, HasSubstr("@link android.R.attr#baz"));
+  EXPECT_THAT(output, HasSubstr("@link app.R.attr#foo"));
+  EXPECT_THAT(output, HasSubstr("@link app.R.attr#bar"));
+}
+
 TEST(JavaClassGeneratorTest, AttrPrivateIsWrittenAsAttr) {
   std::unique_ptr<ResourceTable> table =
       test::ResourceTableBuilder()