AI 144413: am: CL 144342 Fix bag (string-array,etc) behavior with overlays.

We used to replace elements in the default with elements from
  the overlay.  This change causes us to empty the array first
  so if the overlay array is smaller we don't end up with elements
  from the default array showing through at the end of the array.
  Ex: [A,B,C] and overlay [D] should give [D] but used to give
  [D,B,C].
  Original author: rgreenwalt

Automated import of CL 144413

tools/aapt/ResourceTable.cpp

@@ -1109,7 +1109,8 @@ status_t compileResourceFile(Bundle* bundle,
 
                 if (!localHasErrors) {
                     err = outTable->startBag(SourcePos(in->getPrintableSource(), block.getLineNumber()),
-                                             myPackage, curType, ident, parentIdent, &curParams);
+                                             myPackage, curType, ident, parentIdent, &curParams, 
+                                             overwrite);
                     if (err != NO_ERROR) {
                         hasErrors = localHasErrors = true;
                     }
@@ -1409,6 +1410,8 @@ status_t ResourceTable::startBag(const SourcePos& sourcePos,
                                  const ResTable_config* params,
                                  bool replace, bool isId)
 {
+    status_t result = NO_ERROR;
+
     // Check for adding entries in other packages...  for now we do
     // nothing.  We need to do the right thing here to support skinning.
     uint32_t rid = mAssets->getIncludedResources()
@@ -1442,8 +1445,12 @@ status_t ResourceTable::startBag(const SourcePos& sourcePos,
         }
         e->setParent(bagParent);
     }
-    
-    return e->makeItABag(sourcePos);
+
+    if ((result = e->makeItABag(sourcePos)) != NO_ERROR) {
+        return result;
+    }
+ 
+    return e->emptyBag(sourcePos);
 }
 
 status_t ResourceTable::addBag(const SourcePos& sourcePos,
@@ -2798,6 +2805,17 @@ status_t ResourceTable::Entry::addToBag(const SourcePos& sourcePos,
     return NO_ERROR;
 }
 
+status_t ResourceTable::Entry::emptyBag(const SourcePos& sourcePos)
+{
+    status_t err = makeItABag(sourcePos);
+    if (err != NO_ERROR) {
+        return err;
+    }
+
+    mBag.clear();
+    return NO_ERROR;
+}
+
 status_t ResourceTable::Entry::generateAttributes(ResourceTable* table,
                                                   const String16& package)
 {

tools/aapt/ResourceTable.h

@@ -254,7 +254,9 @@ public:
         String16 getParent() const { return mParent; }
 
         status_t makeItABag(const SourcePos& sourcePos);
-        
+
+        status_t emptyBag(const SourcePos& sourcePos);
+ 
         status_t setItem(const SourcePos& pos,
                          const String16& value,
                          const Vector<StringPool::entry_style_span>* style = NULL,