Fix backwards compat problem with AAPT public attrs

AAPT has traditionally assigned resource IDs to public attributes,
and then followed those public definitions with private attributes.

--- PUBLIC ---
| 0x01010234 | attr/color
| 0x01010235 | attr/background

--- PRIVATE ---
| 0x01010236 | attr/secret
| 0x01010237 | attr/shhh

Each release, when attributes are added, they take the place of the private
attributes and the private attributes are shifted down again.

--- PUBLIC ---
| 0x01010234 | attr/color
| 0x01010235 | attr/background
| 0x01010236 | attr/shinyNewAttr
| 0x01010237 | attr/highlyValuedFeature

--- PRIVATE ---
| 0x01010238 | attr/secret
| 0x01010239 | attr/shhh

Platform code may look for private attributes set in a theme. If an app
compiled against a newer version of the platform uses a new public
attribute that happens to have the same ID as the private attribute
the older platform is expecting, then the behavior is undefined.

We get around this by detecting any newly defined attributes (in L),
copy the resource into a -v21 qualified resource, and delete the
attribute from the original resource. This ensures that older platforms
don't see the new attribute, but when running on L+ platforms, the
attribute will be respected.

We still need to address this problem in the platform moving forward,
as this will only help us in the transition from pre L to L.

Bug:17520380
Change-Id: Ia2a985798b50006c21c7c3431d30d9598f27cd91

1 files changed, 21 insertions, 3 deletions

diff --git a/tools/aapt/Resource.cpp b/tools/aapt/Resource.cpp
index afec5edd3f0f..d60520284fa2 100644
--- a/tools/aapt/Resource.cpp
+++ b/tools/aapt/Resource.cpp
@@ -781,12 +781,18 @@ status_t massageManifest(Bundle* bundle, sp<XMLNode> root)
     if (!addTagAttribute(root, RESOURCES_ANDROID_NAMESPACE, "versionName",
             bundle->getVersionName(), errorOnFailedInsert, replaceVersion)) {
         return UNKNOWN_ERROR;
+    } else {
+        const XMLNode::attribute_entry* attr = root->getAttribute(
+                String16(RESOURCES_ANDROID_NAMESPACE), String16("versionName"));
+        if (attr != NULL) {
+            bundle->setVersionName(strdup(String8(attr->string).string()));
+        }
     }
     
+    sp<XMLNode> vers = root->getChildElement(String16(), String16("uses-sdk"));
     if (bundle->getMinSdkVersion() != NULL
             || bundle->getTargetSdkVersion() != NULL
             || bundle->getMaxSdkVersion() != NULL) {
-        sp<XMLNode> vers = root->getChildElement(String16(), String16("uses-sdk"));
         if (vers == NULL) {
             vers = XMLNode::newElement(root->getFilename(), String16(), String16("uses-sdk"));
             root->insertChildAt(vers, 0);
@@ -806,6 +812,14 @@ status_t massageManifest(Bundle* bundle, sp<XMLNode> root)
         }
     }
 
+    if (vers != NULL) {
+        const XMLNode::attribute_entry* attr = vers->getAttribute(
+                String16(RESOURCES_ANDROID_NAMESPACE), String16("minSdkVersion"));
+        if (attr != NULL) {
+            bundle->setMinSdkVersion(strdup(String8(attr->string).string()));
+        }
+    }
+
     if (bundle->getPlatformBuildVersionCode() != "") {
         if (!addTagAttribute(root, "", "platformBuildVersionCode",
                     bundle->getPlatformBuildVersionCode(), errorOnFailedInsert, true)) {
@@ -973,8 +987,8 @@ static ssize_t extractPlatformBuildVersion(ResXMLTree& tree, Bundle* bundle) {
 static ssize_t extractPlatformBuildVersion(AssetManager& assets, Bundle* bundle) {
     int32_t cookie = getPlatformAssetCookie(assets);
     if (cookie == 0) {
-        fprintf(stderr, "ERROR: Platform package not found\n");
-        return UNKNOWN_ERROR;
+        // No platform was loaded.
+        return NO_ERROR;
     }
 
     ResXMLTree tree;
@@ -1500,6 +1514,10 @@ status_t buildResources(Bundle* bundle, const sp<AaptAssets>& assets, sp<ApkBuil
         return err;
     }
 
+    if (table.modifyForCompat(bundle) != NO_ERROR) {
+        return UNKNOWN_ERROR;
+    }
+
     //block.restart();
     //printXMLBlock(&block);