AAPT2: Variety of small fixes to get the build working

- Add option to rename package in AndroidManifest.xml
- Support default versionName and versionCode
- Accept True and False as valid booleans

Change-Id: I400e350b9dcd0fd1c197d1929144299c7823617d
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index a81dc7b..04e8199 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -163,6 +163,11 @@
     }
 
     android::FileMap fileMap;
+    if (fileStats.st_size == 0) {
+        // mmap doesn't like a length of 0. Instead we return an empty FileMap.
+        return std::move(fileMap);
+    }
+
     if (!fileMap.create(path.data(), fd, 0, fileStats.st_size, true)) {
         if (outError) *outError = strerror(errno);
         return {};
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index 9ecc974..7b0c71d 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -175,10 +175,11 @@
         return {};
     }
 
-    std::u16string result(package.data(), package.size());
     if (className.data()[0] != u'.') {
-        result += u'.';
+        return {};
     }
+
+    std::u16string result(package.data(), package.size());
     result.append(className.data(), className.size());
     if (!isJavaClassName(result)) {
         return {};
diff --git a/tools/aapt2/util/Util_test.cpp b/tools/aapt2/util/Util_test.cpp
index 9208e07..1e0c7fa 100644
--- a/tools/aapt2/util/Util_test.cpp
+++ b/tools/aapt2/util/Util_test.cpp
@@ -144,8 +144,7 @@
 
 TEST(UtilTest, FullyQualifiedClassName) {
     Maybe<std::u16string> res = util::getFullyQualifiedClassName(u"android", u"asdf");
-    AAPT_ASSERT_TRUE(res);
-    EXPECT_EQ(res.value(), u"android.asdf");
+    AAPT_ASSERT_FALSE(res);
 
     res = util::getFullyQualifiedClassName(u"android", u".asdf");
     AAPT_ASSERT_TRUE(res);