DO NOT MERGE: Do not allow overlaying of attributes with conflicting formats

aapt(1) does not allow for attributes to be redefined with a different
format. Also, attributes declared with enums or flags are never allowed to be
redefined. This change will not allow attributes to be redefined with a
conflicting format in aapt2.

Bug: 129146717
Test: aapt2_tests
Change-Id: Idc43d6d689199ba2cdc672d009ede22eaa75a10c
diff --git a/tools/aapt2/ResourceTable.cpp b/tools/aapt2/ResourceTable.cpp
index 1773b5a..836e199 100644
--- a/tools/aapt2/ResourceTable.cpp
+++ b/tools/aapt2/ResourceTable.cpp
@@ -267,7 +267,8 @@
 // A DECL will override a USE without error. Two DECLs must match in their format for there to be
 // no error.
 ResourceTable::CollisionResult ResourceTable::ResolveValueCollision(Value* existing,
-                                                                    Value* incoming) {
+                                                                    Value* incoming,
+                                                                    bool overlay) {
   Attribute* existing_attr = ValueCast<Attribute>(existing);
   Attribute* incoming_attr = ValueCast<Attribute>(incoming);
   if (!incoming_attr) {
@@ -281,7 +282,7 @@
     }
     // The existing and incoming values are strong, this is an error
     // if the values are not both attributes.
-    return CollisionResult::kConflict;
+    return overlay ? CollisionResult::kTakeNew : CollisionResult::kConflict;
   }
 
   if (!existing_attr) {
@@ -292,7 +293,7 @@
     }
     // The existing value is not an attribute and it is strong,
     // so the incoming attribute value is an error.
-    return CollisionResult::kConflict;
+    return overlay ? CollisionResult::kTakeNew : CollisionResult::kConflict;
   }
 
   CHECK(incoming_attr != nullptr && existing_attr != nullptr);
@@ -323,8 +324,9 @@
   return CollisionResult::kConflict;
 }
 
-ResourceTable::CollisionResult ResourceTable::IgnoreCollision(Value* /** existing **/,
-                                                              Value* /** incoming **/) {
+ResourceTable::CollisionResult ResourceTable::IgnoreCollision(Value* /* existing */,
+                                                              Value* /* incoming */,
+                                                              bool /* overlay */) {
   return CollisionResult::kKeepBoth;
 }
 
@@ -440,7 +442,7 @@
     // Resource does not exist, add it now.
     config_value->value = std::move(value);
   } else {
-    switch (conflict_resolver(config_value->value.get(), value.get())) {
+    switch (conflict_resolver(config_value->value.get(), value.get(), false /* overlay */)) {
       case CollisionResult::kKeepBoth:
         // Insert the value ignoring for duplicate configurations
         entry->values.push_back(util::make_unique<ResourceConfigValue>(config, product));
diff --git a/tools/aapt2/ResourceTable.h b/tools/aapt2/ResourceTable.h
index 30ba1ae..e879380 100644
--- a/tools/aapt2/ResourceTable.h
+++ b/tools/aapt2/ResourceTable.h
@@ -228,13 +228,13 @@
 
   enum class CollisionResult { kKeepBoth, kKeepOriginal, kConflict, kTakeNew };
 
-  using CollisionResolverFunc = std::function<CollisionResult(Value*, Value*)>;
+  using CollisionResolverFunc = std::function<CollisionResult(Value*, Value*, bool)>;
 
   // When a collision of resources occurs, this method decides which value to keep.
-  static CollisionResult ResolveValueCollision(Value* existing, Value* incoming);
+  static CollisionResult ResolveValueCollision(Value* existing, Value* incoming, bool overlay);
 
   // When a collision of resources occurs, this method keeps both values
-  static CollisionResult IgnoreCollision(Value* existing, Value* incoming);
+  static CollisionResult IgnoreCollision(Value* existing, Value* incoming, bool overlay);
 
   bool AddResource(const ResourceNameRef& name, const android::ConfigDescription& config,
                    const android::StringPiece& product, std::unique_ptr<Value> value,
diff --git a/tools/aapt2/ResourceValues.cpp b/tools/aapt2/ResourceValues.cpp
index 34b46c5..6960127 100644
--- a/tools/aapt2/ResourceValues.cpp
+++ b/tools/aapt2/ResourceValues.cpp
@@ -574,6 +574,10 @@
 }
 
 bool Attribute::IsCompatibleWith(const Attribute& attr) const {
+  if (Equals(&attr)) {
+    return true;
+  }
+
   // If the high bits are set on any of these attribute type masks, then they are incompatible.
   // We don't check that flags and enums are identical.
   if ((type_mask & ~android::ResTable_map::TYPE_ANY) != 0 ||
diff --git a/tools/aapt2/link/TableMerger.cpp b/tools/aapt2/link/TableMerger.cpp
index c0802e6..3f65e86 100644
--- a/tools/aapt2/link/TableMerger.cpp
+++ b/tools/aapt2/link/TableMerger.cpp
@@ -188,7 +188,7 @@
     }
   }
   // Delegate to the default handler.
-  return ResourceTable::ResolveValueCollision(existing, incoming);
+  return ResourceTable::ResolveValueCollision(existing, incoming, true /* overlay */);
 }
 
 static ResourceTable::CollisionResult MergeConfigValue(IAaptContext* context,
@@ -206,15 +206,11 @@
   if (overlay) {
     collision_result = ResolveMergeCollision(dst_value, src_value, pool);
   } else {
-    collision_result = ResourceTable::ResolveValueCollision(dst_value, src_value);
+    collision_result = ResourceTable::ResolveValueCollision(dst_value, src_value,
+                                                            false /* overlay */);
   }
 
   if (collision_result == CollisionResult::kConflict) {
-    if (overlay) {
-      return CollisionResult::kTakeNew;
-    }
-
-    // Error!
     context->GetDiagnostics()->Error(DiagMessage(src_value->GetSource())
                                      << "resource '" << res_name << "' has a conflicting value for "
                                      << "configuration (" << src_config_value->config << ")");
diff --git a/tools/aapt2/link/TableMerger_test.cpp b/tools/aapt2/link/TableMerger_test.cpp
index 9dd31e6..be9c84b 100644
--- a/tools/aapt2/link/TableMerger_test.cpp
+++ b/tools/aapt2/link/TableMerger_test.cpp
@@ -352,6 +352,110 @@
   ASSERT_TRUE(merger.Merge({}, table_b.get(), false /*overlay*/));
 }
 
+TEST_F(TableMergerTest, OverrideAttributeSameFormatsWithOverlay) {
+  std::unique_ptr<ResourceTable> base =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_STRING)
+              .SetWeak(false)
+              .Build())
+          .Build();
+
+  std::unique_ptr<ResourceTable> overlay =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_STRING)
+              .SetWeak(false)
+              .Build())
+          .Build();
+
+  ResourceTable final_table;
+  TableMergerOptions options;
+  options.auto_add_overlay = false;
+  TableMerger merger(context_.get(), &final_table, options);
+
+  ASSERT_TRUE(merger.Merge({}, base.get(), false /*overlay*/));
+  ASSERT_TRUE(merger.Merge({}, overlay.get(), true /*overlay*/));
+}
+
+TEST_F(TableMergerTest, FailToOverrideConflictingAttributeFormatsWithOverlay) {
+  std::unique_ptr<ResourceTable> base =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_ANY)
+              .SetWeak(false)
+              .Build())
+          .Build();
+
+  std::unique_ptr<ResourceTable> overlay =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_STRING)
+              .SetWeak(false)
+              .Build())
+          .Build();
+
+  ResourceTable final_table;
+  TableMergerOptions options;
+  options.auto_add_overlay = false;
+  TableMerger merger(context_.get(), &final_table, options);
+
+  ASSERT_TRUE(merger.Merge({}, base.get(), false /*overlay*/));
+  ASSERT_FALSE(merger.Merge({}, overlay.get(), true /*overlay*/));
+}
+
+TEST_F(TableMergerTest, FailToOverrideConflictingFlagsAndEnumsWithOverlay) {
+  std::unique_ptr<ResourceTable> base =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_FLAGS)
+              .Build())
+          .Build();
+
+  std::unique_ptr<ResourceTable> overlay =
+      test::ResourceTableBuilder()
+          .SetPackageId("", 0x7f)
+          .AddValue("attr/foo", test::AttributeBuilder()
+              .SetTypeMask(android::ResTable_map::TYPE_FLAGS)
+              .SetWeak(false)
+              .Build())
+          .Build();
+
+  ResourceTable final_table;
+  TableMergerOptions options;
+  options.auto_add_overlay = false;
+  TableMerger merger(context_.get(), &final_table, options);
+
+  ASSERT_TRUE(merger.Merge({}, base.get(), false /*overlay*/));
+  ASSERT_FALSE(merger.Merge({}, overlay.get(), true /*overlay*/));
+
+  base = test::ResourceTableBuilder()
+      .SetPackageId("", 0x7f)
+      .AddValue("attr/foo", test::AttributeBuilder()
+          .SetTypeMask(android::ResTable_map::TYPE_ENUM)
+          .Build())
+        .Build();
+
+  overlay = test::ResourceTableBuilder()
+      .SetPackageId("", 0x7f)
+      .AddValue("attr/foo", test::AttributeBuilder()
+          .SetTypeMask(android::ResTable_map::TYPE_ENUM)
+          .SetWeak(false)
+          .Build())
+      .Build();
+
+  ResourceTable final_table2;
+  TableMerger merger2(context_.get(), &final_table2, options);
+
+  ASSERT_TRUE(merger2.Merge({}, base.get(), false /*overlay*/));
+  ASSERT_FALSE(merger2.Merge({}, overlay.get(), true /*overlay*/));
+}
+
 TEST_F(TableMergerTest, FailToMergeNewResourceWithoutAutoAddOverlay) {
   std::unique_ptr<ResourceTable> table_a =
       test::ResourceTableBuilder().SetPackageId("", 0x7f).Build();