AAPT2: Fix processing of quotes in XML

When processing attributes in XML, quotes can't be used to mark a
section as whitespace preserving, so the assumption should be that the
entire string is whitespace preserving, which makes quote characters
literals.

Bug: 62840718
Bug: 62840406
Test: make aapt2_tests
Change-Id: I4afff02148b5b8e78833abf1f323c2f5325d6155

10 files changed, 233 insertions, 253 deletions

diff --git a/libs/androidfw/include/androidfw/StringPiece.h b/libs/androidfw/include/androidfw/StringPiece.h
index a873d66803e7..99b424568a1f 100644
--- a/libs/androidfw/include/androidfw/StringPiece.h
+++ b/libs/androidfw/include/androidfw/StringPiece.h
@@ -37,6 +37,7 @@ class BasicStringPiece {
  public:
   using const_iterator = const TChar*;
   using difference_type = size_t;
+  using size_type = size_t;
 
   // End of string marker.
   constexpr static const size_t npos = static_cast<size_t>(-1);
diff --git a/tools/aapt2/flatten/XmlFlattener.cpp b/tools/aapt2/flatten/XmlFlattener.cpp
index 0711749d0378..bfebedef2a1e 100644
--- a/tools/aapt2/flatten/XmlFlattener.cpp
+++ b/tools/aapt2/flatten/XmlFlattener.cpp
@@ -257,9 +257,11 @@ class XmlFlattenerVisitor : public xml::Visitor {
 
       // Process plain strings to make sure they get properly escaped.
       StringPiece raw_value = xml_attr->value;
-      util::StringBuilder str_builder;
+
+      util::StringBuilder str_builder(true /*preserve_spaces*/);
+      str_builder.Append(xml_attr->value);
+
       if (!options_.keep_raw_values) {
-        str_builder.Append(xml_attr->value);
         raw_value = str_builder.ToString();
       }
 
diff --git a/tools/aapt2/flatten/XmlFlattener_test.cpp b/tools/aapt2/flatten/XmlFlattener_test.cpp
index f1e903f2151e..a57e3178accd 100644
--- a/tools/aapt2/flatten/XmlFlattener_test.cpp
+++ b/tools/aapt2/flatten/XmlFlattener_test.cpp
@@ -23,7 +23,13 @@
 #include "util/BigBuffer.h"
 #include "util/Util.h"
 
-using android::StringPiece16;
+using ::aapt::test::StrEq;
+using ::android::StringPiece16;
+using ::testing::Eq;
+using ::testing::Ge;
+using ::testing::IsNull;
+using ::testing::Ne;
+using ::testing::NotNull;
 
 namespace aapt {
 
@@ -72,163 +78,138 @@ class XmlFlattenerTest : public ::testing::Test {
 };
 
 TEST_F(XmlFlattenerTest, FlattenXmlWithNoCompiledAttributes) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
-            <View xmlns:test="http://com.test"
-                  attr="hey">
-              <Layout test:hello="hi" />
-              <Layout>Some text\\</Layout>
-            </View>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
+      <View xmlns:test="http://com.test" attr="hey">
+          <Layout test:hello="hi" />
+          <Layout>Some text\\</Layout>
+      </View>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
-
-  ASSERT_EQ(android::ResXMLTree::START_NAMESPACE, tree.next());
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_NAMESPACE));
 
   size_t len;
-  const char16_t* namespace_prefix = tree.getNamespacePrefix(&len);
-  EXPECT_EQ(StringPiece16(u"test"), StringPiece16(namespace_prefix, len));
-
-  const char16_t* namespace_uri = tree.getNamespaceUri(&len);
-  ASSERT_EQ(StringPiece16(u"http://com.test"), StringPiece16(namespace_uri, len));
-
-  ASSERT_EQ(android::ResXMLTree::START_TAG, tree.next());
-
-  ASSERT_EQ(nullptr, tree.getElementNamespace(&len));
-  const char16_t* tag_name = tree.getElementName(&len);
-  EXPECT_EQ(StringPiece16(u"View"), StringPiece16(tag_name, len));
-
-  ASSERT_EQ(1u, tree.getAttributeCount());
-  ASSERT_EQ(nullptr, tree.getAttributeNamespace(0, &len));
-  const char16_t* attr_name = tree.getAttributeName(0, &len);
-  EXPECT_EQ(StringPiece16(u"attr"), StringPiece16(attr_name, len));
-
-  EXPECT_EQ(0, tree.indexOfAttribute(nullptr, 0, u"attr", StringPiece16(u"attr").size()));
+  EXPECT_THAT(tree.getNamespacePrefix(&len), StrEq(u"test"));
+  EXPECT_THAT(tree.getNamespaceUri(&len), StrEq(u"http://com.test"));
 
-  ASSERT_EQ(android::ResXMLTree::START_TAG, tree.next());
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_TAG));
+  EXPECT_THAT(tree.getElementNamespace(&len), IsNull());
+  EXPECT_THAT(tree.getElementName(&len), StrEq(u"View"));
 
-  ASSERT_EQ(nullptr, tree.getElementNamespace(&len));
-  tag_name = tree.getElementName(&len);
-  EXPECT_EQ(StringPiece16(u"Layout"), StringPiece16(tag_name, len));
+  ASSERT_THAT(tree.getAttributeCount(), Eq(1u));
+  EXPECT_THAT(tree.getAttributeNamespace(0, &len), IsNull());
+  EXPECT_THAT(tree.getAttributeName(0, &len), StrEq(u"attr"));
 
-  ASSERT_EQ(1u, tree.getAttributeCount());
-  const char16_t* attr_namespace = tree.getAttributeNamespace(0, &len);
-  EXPECT_EQ(StringPiece16(u"http://com.test"), StringPiece16(attr_namespace, len));
+  const StringPiece16 kAttr(u"attr");
+  EXPECT_THAT(tree.indexOfAttribute(nullptr, 0, kAttr.data(), kAttr.size()), Eq(0));
 
-  attr_name = tree.getAttributeName(0, &len);
-  EXPECT_EQ(StringPiece16(u"hello"), StringPiece16(attr_name, len));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_TAG));
+  EXPECT_THAT(tree.getElementNamespace(&len), IsNull());
+  EXPECT_THAT(tree.getElementName(&len), StrEq(u"Layout"));
 
-  ASSERT_EQ(android::ResXMLTree::END_TAG, tree.next());
-  ASSERT_EQ(android::ResXMLTree::START_TAG, tree.next());
+  ASSERT_THAT(tree.getAttributeCount(), Eq(1u));
+  EXPECT_THAT(tree.getAttributeNamespace(0, &len), StrEq(u"http://com.test"));
+  EXPECT_THAT(tree.getAttributeName(0, &len), StrEq(u"hello"));
 
-  ASSERT_EQ(nullptr, tree.getElementNamespace(&len));
-  tag_name = tree.getElementName(&len);
-  EXPECT_EQ(StringPiece16(u"Layout"), StringPiece16(tag_name, len));
-  ASSERT_EQ(0u, tree.getAttributeCount());
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::END_TAG));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_TAG));
 
-  ASSERT_EQ(android::ResXMLTree::TEXT, tree.next());
-  const char16_t* text = tree.getText(&len);
-  EXPECT_EQ(StringPiece16(u"Some text\\"), StringPiece16(text, len));
+  EXPECT_THAT(tree.getElementNamespace(&len), IsNull());
+  EXPECT_THAT(tree.getElementName(&len), StrEq(u"Layout"));
+  ASSERT_THAT(tree.getAttributeCount(), Eq(0u));
 
-  ASSERT_EQ(android::ResXMLTree::END_TAG, tree.next());
-  ASSERT_EQ(nullptr, tree.getElementNamespace(&len));
-  tag_name = tree.getElementName(&len);
-  EXPECT_EQ(StringPiece16(u"Layout"), StringPiece16(tag_name, len));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::TEXT));
+  EXPECT_THAT(tree.getText(&len), StrEq(u"Some text\\"));
 
-  ASSERT_EQ(android::ResXMLTree::END_TAG, tree.next());
-  ASSERT_EQ(nullptr, tree.getElementNamespace(&len));
-  tag_name = tree.getElementName(&len);
-  EXPECT_EQ(StringPiece16(u"View"), StringPiece16(tag_name, len));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::END_TAG));
+  EXPECT_THAT(tree.getElementNamespace(&len), IsNull());
+  EXPECT_THAT(tree.getElementName(&len), StrEq(u"Layout"));
 
-  ASSERT_EQ(android::ResXMLTree::END_NAMESPACE, tree.next());
-  namespace_prefix = tree.getNamespacePrefix(&len);
-  EXPECT_EQ(StringPiece16(u"test"), StringPiece16(namespace_prefix, len));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::END_TAG));
+  EXPECT_THAT(tree.getElementNamespace(&len), IsNull());
+  EXPECT_THAT(tree.getElementName(&len), StrEq(u"View"));
 
-  namespace_uri = tree.getNamespaceUri(&len);
-  ASSERT_EQ(StringPiece16(u"http://com.test"), StringPiece16(namespace_uri, len));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::END_NAMESPACE));
+  EXPECT_THAT(tree.getNamespacePrefix(&len), StrEq(u"test"));
+  EXPECT_THAT(tree.getNamespaceUri(&len), StrEq(u"http://com.test"));
 
-  ASSERT_EQ(android::ResXMLTree::END_DOCUMENT, tree.next());
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::END_DOCUMENT));
 }
 
 TEST_F(XmlFlattenerTest, FlattenCompiledXmlAndStripOnlyTools) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
-            <View xmlns:tools="http://schemas.android.com/tools"
-                xmlns:foo="http://schemas.android.com/foo"
-                foo:bar="Foo"
-                tools:ignore="MissingTranslation"/>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
+      <View xmlns:tools="http://schemas.android.com/tools"
+          xmlns:foo="http://schemas.android.com/foo"
+          foo:bar="Foo"
+          tools:ignore="MissingTranslation"/>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
-
-  ASSERT_EQ(tree.next(), android::ResXMLTree::START_NAMESPACE);
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_NAMESPACE));
 
   size_t len;
-  const char16_t* namespace_prefix = tree.getNamespacePrefix(&len);
-  EXPECT_EQ(StringPiece16(namespace_prefix, len), u"foo");
-
-  const char16_t* namespace_uri = tree.getNamespaceUri(&len);
-  ASSERT_EQ(StringPiece16(namespace_uri, len),
-            u"http://schemas.android.com/foo");
-
-  ASSERT_EQ(tree.next(), android::ResXMLTree::START_TAG);
+  EXPECT_THAT(tree.getNamespacePrefix(&len), StrEq(u"foo"));
+  EXPECT_THAT(tree.getNamespaceUri(&len), StrEq(u"http://schemas.android.com/foo"));
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::START_TAG));
 
-  EXPECT_EQ(tree.indexOfAttribute("http://schemas.android.com/tools", "ignore"),
-            android::NAME_NOT_FOUND);
-  EXPECT_GE(tree.indexOfAttribute("http://schemas.android.com/foo", "bar"), 0);
+  EXPECT_THAT(tree.indexOfAttribute("http://schemas.android.com/tools", "ignore"),
+              Eq(android::NAME_NOT_FOUND));
+  EXPECT_THAT(tree.indexOfAttribute("http://schemas.android.com/foo", "bar"), Ge(0));
 }
 
 TEST_F(XmlFlattenerTest, AssignSpecialAttributeIndices) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
-            <View xmlns:android="http://schemas.android.com/apk/res/android"
-                  android:id="@id/id"
-                  class="str"
-                  style="@id/id"/>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
+      <View xmlns:android="http://schemas.android.com/apk/res/android"
+          android:id="@id/id"
+          class="str"
+          style="@id/id"/>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
 
   while (tree.next() != android::ResXMLTree::START_TAG) {
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::BAD_DOCUMENT);
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::END_DOCUMENT);
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::BAD_DOCUMENT));
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::END_DOCUMENT));
   }
 
-  EXPECT_EQ(tree.indexOfClass(), 0);
-  EXPECT_EQ(tree.indexOfStyle(), 1);
+  EXPECT_THAT(tree.indexOfClass(), Eq(0));
+  EXPECT_THAT(tree.indexOfStyle(), Eq(1));
 }
 
 // The device ResXMLParser in libandroidfw differentiates between empty namespace and null
 // namespace.
 TEST_F(XmlFlattenerTest, NoNamespaceIsNotTheSameAsEmptyNamespace) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom("<View package=\"android\"/>");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(<View package="android"/>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
 
   while (tree.next() != android::ResXMLTree::START_TAG) {
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::BAD_DOCUMENT);
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::END_DOCUMENT);
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::BAD_DOCUMENT));
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::END_DOCUMENT));
   }
 
   const StringPiece16 kPackage = u"package";
-  EXPECT_GE(tree.indexOfAttribute(nullptr, 0, kPackage.data(), kPackage.size()), 0);
+  EXPECT_THAT(tree.indexOfAttribute(nullptr, 0, kPackage.data(), kPackage.size()), Ge(0));
 }
 
 TEST_F(XmlFlattenerTest, EmptyStringValueInAttributeIsNotNull) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom("<View package=\"\"/>");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(<View package=""/>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
 
   while (tree.next() != android::ResXMLTree::START_TAG) {
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::BAD_DOCUMENT);
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::END_DOCUMENT);
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::BAD_DOCUMENT));
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::END_DOCUMENT));
   }
 
   const StringPiece16 kPackage = u"package";
   ssize_t idx = tree.indexOfAttribute(nullptr, 0, kPackage.data(), kPackage.size());
-  ASSERT_GE(idx, 0);
+  ASSERT_THAT(idx, Ge(0));
 
   size_t len;
-  EXPECT_NE(nullptr, tree.getAttributeStringValue(idx, &len));
+  EXPECT_THAT(tree.getAttributeStringValue(idx, &len), NotNull());
 }
 
 TEST_F(XmlFlattenerTest, FlattenNonStandardPackageId) {
@@ -236,11 +217,11 @@ TEST_F(XmlFlattenerTest, FlattenNonStandardPackageId) {
   context_->SetPackageId(0x80);
   context_->SetNameManglerPolicy({"com.app.test.feature"});
 
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"EOF(
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDomForPackageName(context_.get(), R"(
       <View xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:app="http://schemas.android.com/apk/res-auto"
             android:id="@id/foo"
-            app:foo="@id/foo" />)EOF");
+            app:foo="@id/foo" />)");
 
   XmlReferenceLinker linker;
   ASSERT_TRUE(linker.Consume(context_.get(), doc.get()));
@@ -253,59 +234,57 @@ TEST_F(XmlFlattenerTest, FlattenNonStandardPackageId) {
   ASSERT_TRUE(Flatten(doc.get(), &tree));
 
   while (tree.next() != android::ResXMLTree::START_TAG) {
-    ASSERT_NE(android::ResXMLTree::BAD_DOCUMENT, tree.getEventType());
-    ASSERT_NE(android::ResXMLTree::END_DOCUMENT, tree.getEventType());
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::BAD_DOCUMENT));
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::END_DOCUMENT));
   }
 
   ssize_t idx;
 
   idx = tree.indexOfAttribute(xml::kSchemaAndroid, "id");
-  ASSERT_GE(idx, 0);
-  EXPECT_EQ(idx, tree.indexOfID());
-  EXPECT_EQ(ResourceId(0x010100d0), ResourceId(tree.getAttributeNameResID(idx)));
+  ASSERT_THAT(idx, Ge(0));
+  EXPECT_THAT(tree.indexOfID(), Eq(idx));
+  EXPECT_THAT(tree.getAttributeNameResID(idx), Eq(0x010100d0u));
 
   idx = tree.indexOfAttribute(xml::kSchemaAuto, "foo");
-  ASSERT_GE(idx, 0);
-  EXPECT_EQ(ResourceId(0x80010000), ResourceId(tree.getAttributeNameResID(idx)));
-  EXPECT_EQ(android::Res_value::TYPE_REFERENCE, tree.getAttributeDataType(idx));
-  EXPECT_EQ(ResourceId(0x80020000), tree.getAttributeData(idx));
+  ASSERT_THAT(idx, Ge(0));
+  EXPECT_THAT(tree.getAttributeNameResID(idx), Eq(0x80010000u));
+  EXPECT_THAT(tree.getAttributeDataType(idx), Eq(android::Res_value::TYPE_REFERENCE));
+  EXPECT_THAT(tree.getAttributeData(idx), Eq(int32_t(0x80020000)));
 }
 
 TEST_F(XmlFlattenerTest, ProcessEscapedStrings) {
   std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(
-      R"EOF(<element value="\?hello" pattern="\\d{5}">\\d{5}</element>)EOF");
+      R"(<element value="\?hello" pattern="\\d{5}" other="&quot;">\\d{5}</element>)");
 
   android::ResXMLTree tree;
   ASSERT_TRUE(Flatten(doc.get(), &tree));
 
   while (tree.next() != android::ResXMLTree::START_TAG) {
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::BAD_DOCUMENT);
-    ASSERT_NE(tree.getEventType(), android::ResXMLTree::END_DOCUMENT);
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::BAD_DOCUMENT));
+    ASSERT_THAT(tree.getEventType(), Ne(android::ResXMLTree::END_DOCUMENT));
   }
 
   const StringPiece16 kValue = u"value";
   const StringPiece16 kPattern = u"pattern";
+  const StringPiece16 kOther = u"other";
 
   size_t len;
   ssize_t idx;
-  const char16_t* str16;
 
   idx = tree.indexOfAttribute(nullptr, 0, kValue.data(), kValue.size());
-  ASSERT_GE(idx, 0);
-  str16 = tree.getAttributeStringValue(idx, &len);
-  ASSERT_NE(nullptr, str16);
-  EXPECT_EQ(StringPiece16(u"?hello"), StringPiece16(str16, len));
+  ASSERT_THAT(idx, Ge(0));
+  EXPECT_THAT(tree.getAttributeStringValue(idx, &len), StrEq(u"?hello"));
 
   idx = tree.indexOfAttribute(nullptr, 0, kPattern.data(), kPattern.size());
-  ASSERT_GE(idx, 0);
-  str16 = tree.getAttributeStringValue(idx, &len);
-  ASSERT_NE(nullptr, str16);
-  EXPECT_EQ(StringPiece16(u"\\d{5}"), StringPiece16(str16, len));
-
-  ASSERT_EQ(android::ResXMLTree::TEXT, tree.next());
-  str16 = tree.getText(&len);
-  ASSERT_NE(nullptr, str16);
-  EXPECT_EQ(StringPiece16(u"\\d{5}"), StringPiece16(str16, len));
+  ASSERT_THAT(idx, Ge(0));
+  EXPECT_THAT(tree.getAttributeStringValue(idx, &len), StrEq(u"\\d{5}"));
+
+  idx = tree.indexOfAttribute(nullptr, 0, kOther.data(), kOther.size());
+  ASSERT_THAT(idx, Ge(0));
+  EXPECT_THAT(tree.getAttributeStringValue(idx, &len), StrEq(u"\""));
+
+  ASSERT_THAT(tree.next(), Eq(android::ResXMLTree::TEXT));
+  EXPECT_THAT(tree.getText(&len), StrEq(u"\\d{5}"));
 }
 
 }  // namespace aapt
diff --git a/tools/aapt2/readme.md b/tools/aapt2/readme.md
index 01d4a4160615..e128c13460d7 100644
--- a/tools/aapt2/readme.md
+++ b/tools/aapt2/readme.md
@@ -11,6 +11,8 @@
   the set of Proguard keep rules. (bug 62216174)
 - Automatically version XML `<adaptive-icon>` resources to v26. (bug 62316340)
 - Fixed issue where escaped unicode characters would generate malformed UTF-8. (bug 62839202)
+- Fixed issue where apostrophes or quotes used in XML attribute values were ignored.
+  (bug 62840406, 62840718)
 
 ## Version 2.17
 ### `aapt2 ...`
diff --git a/tools/aapt2/test/Common.h b/tools/aapt2/test/Common.h
index 11821031b131..d7b46caf8c94 100644
--- a/tools/aapt2/test/Common.h
+++ b/tools/aapt2/test/Common.h
@@ -136,6 +136,12 @@ void PrintTo(const Maybe<T>& value, std::ostream* out) {
 
 namespace test {
 
+MATCHER_P(StrEq, a,
+          std::string(negation ? "isn't" : "is") + " equal to " +
+              ::testing::PrintToString(android::StringPiece16(a))) {
+  return android::StringPiece16(arg) == a;
+}
+
 MATCHER_P(ValueEq, a,
           std::string(negation ? "isn't" : "is") + " equal to " + ::testing::PrintToString(a)) {
   return arg.Equals(&a);
diff --git a/tools/aapt2/util/Maybe.h b/tools/aapt2/util/Maybe.h
index b43f8e87fd68..9a82418e0a5a 100644
--- a/tools/aapt2/util/Maybe.h
+++ b/tools/aapt2/util/Maybe.h
@@ -281,16 +281,12 @@ inline Maybe<T> make_nothing() {
   return Maybe<T>();
 }
 
-/**
- * Define the == operator between Maybe<T> and Maybe<U> only if the operator T
- * == U is defined.
- * That way the compiler will show an error at the callsite when comparing two
- * Maybe<> objects
- * whose inner types can't be compared.
- */
+// Define the == operator between Maybe<T> and Maybe<U> only if the operator T == U is defined.
+// That way the compiler will show an error at the callsite when comparing two Maybe<> objects
+// whose inner types can't be compared.
 template <typename T, typename U>
-typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator==(
-    const Maybe<T>& a, const Maybe<U>& b) {
+typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator==(const Maybe<T>& a,
+                                                                       const Maybe<U>& b) {
   if (a && b) {
     return a.value() == b.value();
   } else if (!a && !b) {
@@ -299,18 +295,22 @@ typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator==(
   return false;
 }
 
-/**
- * Same as operator== but negated.
- */
 template <typename T, typename U>
-typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator!=(
-    const Maybe<T>& a, const Maybe<U>& b) {
+typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator==(const Maybe<T>& a,
+                                                                       const U& b) {
+  return a ? a.value() == b : false;
+}
+
+// Same as operator== but negated.
+template <typename T, typename U>
+typename std::enable_if<has_eq_op<T, U>::value, bool>::type operator!=(const Maybe<T>& a,
+                                                                       const Maybe<U>& b) {
   return !(a == b);
 }
 
 template <typename T, typename U>
-typename std::enable_if<has_lt_op<T, U>::value, bool>::type operator<(
-    const Maybe<T>& a, const Maybe<U>& b) {
+typename std::enable_if<has_lt_op<T, U>::value, bool>::type operator<(const Maybe<T>& a,
+                                                                      const Maybe<U>& b) {
   if (a && b) {
     return a.value() < b.value();
   } else if (!a && !b) {
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index 9fde1b474bf3..51a75d7556ad 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -327,6 +327,9 @@ static bool IsCodepointSpace(char32_t codepoint) {
   return isspace(static_cast<char>(codepoint));
 }
 
+StringBuilder::StringBuilder(bool preserve_spaces) : preserve_spaces_(preserve_spaces) {
+}
+
 StringBuilder& StringBuilder::Append(const StringPiece& str) {
   if (!error_.empty()) {
     return *this;
@@ -372,14 +375,12 @@ StringBuilder& StringBuilder::Append(const StringPiece& str) {
       }
       last_char_was_escape_ = false;
 
-    } else if (codepoint == U'"') {
+    } else if (!preserve_spaces_ && codepoint == U'"') {
       if (!quote_ && trailing_space_) {
-        // We found an opening quote, and we have
-        // trailing space, so we should append that
+        // We found an opening quote, and we have trailing space, so we should append that
         // space now.
         if (trailing_space_) {
-          // We had trailing whitespace, so
-          // replace with a single space.
+          // We had trailing whitespace, so replace with a single space.
           if (!str_.empty()) {
             str_ += ' ';
           }
@@ -388,7 +389,7 @@ StringBuilder& StringBuilder::Append(const StringPiece& str) {
       }
       quote_ = !quote_;
 
-    } else if (codepoint == U'\'' && !quote_) {
+    } else if (!preserve_spaces_ && codepoint == U'\'' && !quote_) {
       // This should be escaped.
       error_ = "unescaped apostrophe";
       return *this;
@@ -405,7 +406,7 @@ StringBuilder& StringBuilder::Append(const StringPiece& str) {
       }
       last_char_was_escape_ = true;
     } else {
-      if (quote_) {
+      if (preserve_spaces_ || quote_) {
         // Quotes mean everything is taken, including whitespace.
         AppendCodepointToUtf8String(codepoint, &str_);
       } else {
diff --git a/tools/aapt2/util/Util.h b/tools/aapt2/util/Util.h
index 8bca9dd739bf..410258c40209 100644
--- a/tools/aapt2/util/Util.h
+++ b/tools/aapt2/util/Util.h
@@ -171,6 +171,8 @@ bool VerifyJavaStringFormat(const android::StringPiece& str);
 
 class StringBuilder {
  public:
+  explicit StringBuilder(bool preserve_spaces = false);
+
   StringBuilder& Append(const android::StringPiece& str);
   const std::string& ToString() const;
   const std::string& Error() const;
@@ -184,6 +186,7 @@ class StringBuilder {
   explicit operator bool() const;
 
  private:
+  bool preserve_spaces_;
   std::string str_;
   size_t utf16_len_ = 0;
   bool quote_ = false;
diff --git a/tools/aapt2/util/Util_test.cpp b/tools/aapt2/util/Util_test.cpp
index a09001a71efc..adb52911ab82 100644
--- a/tools/aapt2/util/Util_test.cpp
+++ b/tools/aapt2/util/Util_test.cpp
@@ -20,16 +20,17 @@
 
 #include "test/Test.h"
 
-using android::StringPiece;
+using ::android::StringPiece;
+using ::testing::Eq;
+using ::testing::Ne;
+using ::testing::SizeIs;
 
 namespace aapt {
 
 TEST(UtilTest, TrimOnlyWhitespace) {
-  const std::string full = "\n        ";
-
-  StringPiece trimmed = util::TrimWhitespace(full);
+  const StringPiece trimmed = util::TrimWhitespace("\n        ");
   EXPECT_TRUE(trimmed.empty());
-  EXPECT_EQ(0u, trimmed.size());
+  EXPECT_THAT(trimmed, SizeIs(0u));
 }
 
 TEST(UtilTest, StringEndsWith) {
@@ -41,85 +42,74 @@ TEST(UtilTest, StringStartsWith) {
 }
 
 TEST(UtilTest, StringBuilderSplitEscapeSequence) {
-  EXPECT_EQ(StringPiece("this is a new\nline."), util::StringBuilder()
-                                                     .Append("this is a new\\")
-                                                     .Append("nline.")
-                                                     .ToString());
+  EXPECT_THAT(util::StringBuilder().Append("this is a new\\").Append("nline.").ToString(),
+              Eq("this is a new\nline."));
 }
 
 TEST(UtilTest, StringBuilderWhitespaceRemoval) {
-  EXPECT_EQ(StringPiece("hey guys this is so cool"),
-            util::StringBuilder()
-                .Append("    hey guys ")
-                .Append(" this is so cool ")
-                .ToString());
-
-  EXPECT_EQ(StringPiece(" wow,  so many \t spaces. what?"),
-            util::StringBuilder()
-                .Append(" \" wow,  so many \t ")
-                .Append("spaces. \"what? ")
-                .ToString());
-
-  EXPECT_EQ(StringPiece("where is the pie?"), util::StringBuilder()
-                                                  .Append("  where \t ")
-                                                  .Append(" \nis the "
-                                                          " pie?")
-                                                  .ToString());
+  EXPECT_THAT(util::StringBuilder().Append("    hey guys ").Append(" this is so cool ").ToString(),
+              Eq("hey guys this is so cool"));
+  EXPECT_THAT(
+      util::StringBuilder().Append(" \" wow,  so many \t ").Append("spaces. \"what? ").ToString(),
+      Eq(" wow,  so many \t spaces. what?"));
+  EXPECT_THAT(util::StringBuilder().Append("  where \t ").Append(" \nis the pie?").ToString(),
+              Eq("where is the pie?"));
 }
 
 TEST(UtilTest, StringBuilderEscaping) {
-  EXPECT_EQ(StringPiece("hey guys\n this \t is so\\ cool"),
-            util::StringBuilder()
-                .Append("    hey guys\\n ")
-                .Append(" this \\t is so\\\\ cool ")
-                .ToString());
-
-  EXPECT_EQ(StringPiece("@?#\\\'"),
-            util::StringBuilder().Append("\\@\\?\\#\\\\\\'").ToString());
+  EXPECT_THAT(util::StringBuilder()
+                  .Append("    hey guys\\n ")
+                  .Append(" this \\t is so\\\\ cool ")
+                  .ToString(),
+              Eq("hey guys\n this \t is so\\ cool"));
+  EXPECT_THAT(util::StringBuilder().Append("\\@\\?\\#\\\\\\'").ToString(), Eq("@?#\\\'"));
 }
 
 TEST(UtilTest, StringBuilderMisplacedQuote) {
-  util::StringBuilder builder{};
+  util::StringBuilder builder;
   EXPECT_FALSE(builder.Append("they're coming!"));
 }
 
 TEST(UtilTest, StringBuilderUnicodeCodes) {
-  EXPECT_EQ(std::string("\u00AF\u0AF0 woah"),
-            util::StringBuilder().Append("\\u00AF\\u0AF0 woah").ToString());
-
+  EXPECT_THAT(util::StringBuilder().Append("\\u00AF\\u0AF0 woah").ToString(),
+              Eq("\u00AF\u0AF0 woah"));
   EXPECT_FALSE(util::StringBuilder().Append("\\u00 yo"));
 }
 
+TEST(UtilTest, StringBuilderPreserveSpaces) {
+  EXPECT_THAT(util::StringBuilder(true /*preserve_spaces*/).Append("\"").ToString(), Eq("\""));
+}
+
 TEST(UtilTest, TokenizeInput) {
   auto tokenizer = util::Tokenize(StringPiece("this| is|the|end"), '|');
   auto iter = tokenizer.begin();
-  ASSERT_EQ(*iter, StringPiece("this"));
+  ASSERT_THAT(*iter, Eq("this"));
   ++iter;
-  ASSERT_EQ(*iter, StringPiece(" is"));
+  ASSERT_THAT(*iter, Eq(" is"));
   ++iter;
-  ASSERT_EQ(*iter, StringPiece("the"));
+  ASSERT_THAT(*iter, Eq("the"));
   ++iter;
-  ASSERT_EQ(*iter, StringPiece("end"));
+  ASSERT_THAT(*iter, Eq("end"));
   ++iter;
-  ASSERT_EQ(tokenizer.end(), iter);
+  ASSERT_THAT(iter, Eq(tokenizer.end()));
 }
 
 TEST(UtilTest, TokenizeEmptyString) {
   auto tokenizer = util::Tokenize(StringPiece(""), '|');
   auto iter = tokenizer.begin();
-  ASSERT_NE(tokenizer.end(), iter);
-  ASSERT_EQ(StringPiece(), *iter);
+  ASSERT_THAT(iter, Ne(tokenizer.end()));
+  ASSERT_THAT(*iter, Eq(StringPiece()));
   ++iter;
-  ASSERT_EQ(tokenizer.end(), iter);
+  ASSERT_THAT(iter, Eq(tokenizer.end()));
 }
 
 TEST(UtilTest, TokenizeAtEnd) {
   auto tokenizer = util::Tokenize(StringPiece("one."), '.');
   auto iter = tokenizer.begin();
-  ASSERT_EQ(*iter, StringPiece("one"));
+  ASSERT_THAT(*iter, Eq("one"));
   ++iter;
-  ASSERT_NE(iter, tokenizer.end());
-  ASSERT_EQ(*iter, StringPiece());
+  ASSERT_THAT(iter, Ne(tokenizer.end()));
+  ASSERT_THAT(*iter, Eq(StringPiece()));
 }
 
 TEST(UtilTest, IsJavaClassName) {
@@ -146,52 +136,34 @@ TEST(UtilTest, IsJavaPackageName) {
 }
 
 TEST(UtilTest, FullyQualifiedClassName) {
-  Maybe<std::string> res = util::GetFullyQualifiedClassName("android", ".asdf");
-  ASSERT_TRUE(res);
-  EXPECT_EQ(res.value(), "android.asdf");
-
-  res = util::GetFullyQualifiedClassName("android", ".a.b");
-  ASSERT_TRUE(res);
-  EXPECT_EQ(res.value(), "android.a.b");
-
-  res = util::GetFullyQualifiedClassName("android", "a.b");
-  ASSERT_TRUE(res);
-  EXPECT_EQ(res.value(), "a.b");
-
-  res = util::GetFullyQualifiedClassName("", "a.b");
-  ASSERT_TRUE(res);
-  EXPECT_EQ(res.value(), "a.b");
-
-  res = util::GetFullyQualifiedClassName("android", "Class");
-  ASSERT_TRUE(res);
-  EXPECT_EQ(res.value(), "android.Class");
-
-  res = util::GetFullyQualifiedClassName("", "");
-  ASSERT_FALSE(res);
-
-  res = util::GetFullyQualifiedClassName("android", "./Apple");
-  ASSERT_FALSE(res);
+  EXPECT_THAT(util::GetFullyQualifiedClassName("android", ".asdf"), Eq("android.asdf"));
+  EXPECT_THAT(util::GetFullyQualifiedClassName("android", ".a.b"), Eq("android.a.b"));
+  EXPECT_THAT(util::GetFullyQualifiedClassName("android", "a.b"), Eq("a.b"));
+  EXPECT_THAT(util::GetFullyQualifiedClassName("", "a.b"), Eq("a.b"));
+  EXPECT_THAT(util::GetFullyQualifiedClassName("android", "Class"), Eq("android.Class"));
+  EXPECT_FALSE(util::GetFullyQualifiedClassName("", ""));
+  EXPECT_FALSE(util::GetFullyQualifiedClassName("android", "./Apple"));
 }
 
 TEST(UtilTest, ExtractResourcePathComponents) {
   StringPiece prefix, entry, suffix;
   ASSERT_TRUE(util::ExtractResFilePathParts("res/xml-sw600dp/entry.xml", &prefix, &entry, &suffix));
-  EXPECT_EQ(prefix, "res/xml-sw600dp/");
-  EXPECT_EQ(entry, "entry");
-  EXPECT_EQ(suffix, ".xml");
+  EXPECT_THAT(prefix, Eq("res/xml-sw600dp/"));
+  EXPECT_THAT(entry, Eq("entry"));
+  EXPECT_THAT(suffix, Eq(".xml"));
 
   ASSERT_TRUE(util::ExtractResFilePathParts("res/xml-sw600dp/entry.9.png", &prefix, &entry, &suffix));
-  EXPECT_EQ(prefix, "res/xml-sw600dp/");
-  EXPECT_EQ(entry, "entry");
-  EXPECT_EQ(suffix, ".9.png");
+  EXPECT_THAT(prefix, Eq("res/xml-sw600dp/"));
+  EXPECT_THAT(entry, Eq("entry"));
+  EXPECT_THAT(suffix, Eq(".9.png"));
+
+  ASSERT_TRUE(util::ExtractResFilePathParts("res//.", &prefix, &entry, &suffix));
+  EXPECT_THAT(prefix, Eq("res//"));
+  EXPECT_THAT(entry, Eq(""));
+  EXPECT_THAT(suffix, Eq("."));
 
   EXPECT_FALSE(util::ExtractResFilePathParts("AndroidManifest.xml", &prefix, &entry, &suffix));
   EXPECT_FALSE(util::ExtractResFilePathParts("res/.xml", &prefix, &entry, &suffix));
-
-  ASSERT_TRUE(util::ExtractResFilePathParts("res//.", &prefix, &entry, &suffix));
-  EXPECT_EQ(prefix, "res//");
-  EXPECT_EQ(entry, "");
-  EXPECT_EQ(suffix, ".");
 }
 
 TEST(UtilTest, VerifyJavaStringFormat) {
diff --git a/tools/aapt2/xml/XmlDom_test.cpp b/tools/aapt2/xml/XmlDom_test.cpp
index c1aa10b89a2f..f0122e8c617a 100644
--- a/tools/aapt2/xml/XmlDom_test.cpp
+++ b/tools/aapt2/xml/XmlDom_test.cpp
@@ -21,7 +21,9 @@
 
 #include "test/Test.h"
 
+using ::testing::Eq;
 using ::testing::NotNull;
+using ::testing::SizeIs;
 
 namespace aapt {
 
@@ -30,47 +32,59 @@ constexpr const char* kXmlPreamble =
 
 TEST(XmlDomTest, Inflate) {
   std::stringstream in(kXmlPreamble);
-  in << R"EOF(
-        <Layout xmlns:android="http://schemas.android.com/apk/res/android"
-                android:layout_width="match_parent"
-                android:layout_height="wrap_content">
-            <TextView android:id="@+id/id"
-                      android:layout_width="wrap_content"
-                      android:layout_height="wrap_content" />
-        </Layout>
-    )EOF";
-
-  const Source source = {"test.xml"};
+  in << R"(
+      <Layout xmlns:android="http://schemas.android.com/apk/res/android"
+          android:layout_width="match_parent"
+          android:layout_height="wrap_content">
+        <TextView android:id="@+id/id"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content" />
+      </Layout>)";
+
+  const Source source("test.xml");
   StdErrDiagnostics diag;
   std::unique_ptr<xml::XmlResource> doc = xml::Inflate(&in, &diag, source);
   ASSERT_THAT(doc, NotNull());
 
   xml::Namespace* ns = xml::NodeCast<xml::Namespace>(doc->root.get());
   ASSERT_THAT(ns, NotNull());
-  EXPECT_EQ(ns->namespace_uri, xml::kSchemaAndroid);
-  EXPECT_EQ(ns->namespace_prefix, "android");
+  EXPECT_THAT(ns->namespace_uri, Eq(xml::kSchemaAndroid));
+  EXPECT_THAT(ns->namespace_prefix, Eq("android"));
 }
 
 // Escaping is handled after parsing of the values for resource-specific values.
 TEST(XmlDomTest, ForwardEscapes) {
-  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"EOF(
-      <element value="\?hello" pattern="\\d{5}">\\d{5}</element>)EOF");
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(
+      <element value="\?hello" pattern="\\d{5}">\\d{5}</element>)");
 
-  xml::Element* el = xml::FindRootElement(doc->root.get());
+  xml::Element* el = xml::FindRootElement(doc.get());
   ASSERT_THAT(el, NotNull());
 
   xml::Attribute* attr = el->FindAttribute({}, "pattern");
   ASSERT_THAT(attr, NotNull());
-  EXPECT_EQ("\\\\d{5}", attr->value);
+  EXPECT_THAT(attr->value, Eq("\\\\d{5}"));
 
   attr = el->FindAttribute({}, "value");
   ASSERT_THAT(attr, NotNull());
-  EXPECT_EQ("\\?hello", attr->value);
+  EXPECT_THAT(attr->value, Eq("\\?hello"));
+
+  ASSERT_THAT(el->children, SizeIs(1u));
 
-  ASSERT_EQ(1u, el->children.size());
   xml::Text* text = xml::NodeCast<xml::Text>(el->children[0].get());
   ASSERT_THAT(text, NotNull());
-  EXPECT_EQ("\\\\d{5}", text->text);
+  EXPECT_THAT(text->text, Eq("\\\\d{5}"));
+}
+
+TEST(XmlDomTest, XmlEscapeSequencesAreParsed) {
+  std::unique_ptr<xml::XmlResource> doc = test::BuildXmlDom(R"(<element value="&quot;" />)");
+
+  xml::Element* el = xml::FindRootElement(doc.get());
+  ASSERT_THAT(el, NotNull());
+
+  xml::Attribute* attr = el->FindAttribute({}, "value");
+  ASSERT_THAT(attr, NotNull());
+
+  EXPECT_THAT(attr->value, Eq("\""));
 }
 
 }  // namespace aapt