diff --git a/tools/aapt/Bundle.h b/tools/aapt/Bundle.h
index a5aa0b5..be08291 100644
--- a/tools/aapt/Bundle.h
+++ b/tools/aapt/Bundle.h
@@ -61,7 +61,7 @@
           mMinSdkVersion(NULL), mTargetSdkVersion(NULL), mMaxSdkVersion(NULL),
           mVersionCode(NULL), mVersionName(NULL), mCustomPackage(NULL), mExtraPackages(NULL),
           mMaxResVersion(NULL), mDebugMode(false), mNonConstantId(false), mProduct(NULL),
-          mUseCrunchCache(false), mArgc(0), mArgv(NULL)
+          mUseCrunchCache(false), mErrorOnFailedInsert(false), mArgc(0), mArgv(NULL)
         {}
     ~Bundle(void) {}
 
@@ -110,6 +110,8 @@
     void setAutoAddOverlay(bool val) { mAutoAddOverlay = val; }
     bool getGenDependencies() { return mGenDependencies; }
     void setGenDependencies(bool val) { mGenDependencies = val; }
+    bool getErrorOnFailedInsert() { return mErrorOnFailedInsert; }
+    void setErrorOnFailedInsert(bool val) { mErrorOnFailedInsert = val; }
 
     bool getUTF16StringsOption() {
         return mWantUTF16 || !isMinSdkAtLeast(SDK_FROYO);
@@ -276,6 +278,7 @@
     bool        mNonConstantId;
     const char* mProduct;
     bool        mUseCrunchCache;
+    bool        mErrorOnFailedInsert;
 
     /* file specification */
     int         mArgc;
diff --git a/tools/aapt/Main.cpp b/tools/aapt/Main.cpp
index 9570c66..1773f48 100644
--- a/tools/aapt/Main.cpp
+++ b/tools/aapt/Main.cpp
@@ -177,6 +177,11 @@
         "       Make the resources ID non constant. This is required to make an R java class\n"
         "       that does not contain the final value but is used to make reusable compiled\n"
         "       libraries that need to access resources.\n"
+        "   --error-on-failed-insert\n"
+        "       Forces aapt to return an error if it fails to insert values into the manifest\n"
+        "       with --debug-mode, --min-sdk-version, --target-sdk-version --version-code\n"
+        "       and --version-name.\n"
+        "       Insertion typically fails if the manifest already defines the attribute.\n"
         "   --ignore-assets\n"
         "       Assets to be ignored. Default pattern is:\n"
         "       %s\n",
@@ -542,6 +547,8 @@
                     bundle.setInstrumentationPackageNameOverride(argv[0]);
                 } else if (strcmp(cp, "-auto-add-overlay") == 0) {
                     bundle.setAutoAddOverlay(true);
+                } else if (strcmp(cp, "-error-on-failed-insert") == 0) {
+                    bundle.setErrorOnFailedInsert(true);
                 } else if (strcmp(cp, "-product") == 0) {
                     argc--;
                     argv++;
diff --git a/tools/aapt/Resource.cpp b/tools/aapt/Resource.cpp
index a69adc1..e2e0dc3 100644
--- a/tools/aapt/Resource.cpp
+++ b/tools/aapt/Resource.cpp
@@ -673,24 +673,40 @@
     return true;
 }
 
-void addTagAttribute(const sp<XMLNode>& node, const char* ns8,
-        const char* attr8, const char* value)
+/*
+ * Inserts an attribute in a given node, only if the attribute does not
+ * exist.
+ * If errorOnFailedInsert is true, and the attribute already exists, returns false.
+ * Returns true otherwise, even if the attribute already exists.
+ */
+bool addTagAttribute(const sp<XMLNode>& node, const char* ns8,
+        const char* attr8, const char* value, bool errorOnFailedInsert)
 {
     if (value == NULL) {
-        return;
+        return true;
     }
-    
+
     const String16 ns(ns8);
     const String16 attr(attr8);
-    
+
     if (node->getAttribute(ns, attr) != NULL) {
+        if (errorOnFailedInsert) {
+            fprintf(stderr, "Error: AndroidManifest.xml already defines %s (in %s);"
+                            " cannot insert new value %s.\n",
+                    String8(attr).string(), String8(ns).string(), value);
+            return false;
+        }
+
         fprintf(stderr, "Warning: AndroidManifest.xml already defines %s (in %s);"
                         " using existing value in manifest.\n",
                 String8(attr).string(), String8(ns).string());
-        return;
+
+        // don't stop the build.
+        return true;
     }
     
     node->addAttribute(ns, attr, String16(value));
+    return true;
 }
 
 static void fullyQualifyClassName(const String8& package, sp<XMLNode> node,
@@ -728,11 +744,17 @@
         fprintf(stderr, "No <manifest> tag.\n");
         return UNKNOWN_ERROR;
     }
-    
-    addTagAttribute(root, RESOURCES_ANDROID_NAMESPACE, "versionCode",
-            bundle->getVersionCode());
-    addTagAttribute(root, RESOURCES_ANDROID_NAMESPACE, "versionName",
-            bundle->getVersionName());
+
+    bool errorOnFailedInsert = bundle->getErrorOnFailedInsert();
+
+    if (!addTagAttribute(root, RESOURCES_ANDROID_NAMESPACE, "versionCode",
+            bundle->getVersionCode(), errorOnFailedInsert)) {
+        return UNKNOWN_ERROR;
+    }
+    if (!addTagAttribute(root, RESOURCES_ANDROID_NAMESPACE, "versionName",
+            bundle->getVersionName(), errorOnFailedInsert)) {
+        return UNKNOWN_ERROR;
+    }
     
     if (bundle->getMinSdkVersion() != NULL
             || bundle->getTargetSdkVersion() != NULL
@@ -743,18 +765,27 @@
             root->insertChildAt(vers, 0);
         }
         
-        addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "minSdkVersion",
-                bundle->getMinSdkVersion());
-        addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "targetSdkVersion",
-                bundle->getTargetSdkVersion());
-        addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "maxSdkVersion",
-                bundle->getMaxSdkVersion());
+        if (!addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "minSdkVersion",
+                bundle->getMinSdkVersion(), errorOnFailedInsert)) {
+            return UNKNOWN_ERROR;
+        }
+        if (!addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "targetSdkVersion",
+                bundle->getTargetSdkVersion(), errorOnFailedInsert)) {
+            return UNKNOWN_ERROR;
+        }
+        if (!addTagAttribute(vers, RESOURCES_ANDROID_NAMESPACE, "maxSdkVersion",
+                bundle->getMaxSdkVersion(), errorOnFailedInsert)) {
+            return UNKNOWN_ERROR;
+        }
     }
 
     if (bundle->getDebugMode()) {
         sp<XMLNode> application = root->getChildElement(String16(), String16("application"));
         if (application != NULL) {
-            addTagAttribute(application, RESOURCES_ANDROID_NAMESPACE, "debuggable", "true");
+            if (!addTagAttribute(application, RESOURCES_ANDROID_NAMESPACE, "debuggable", "true",
+                    errorOnFailedInsert)) {
+                return UNKNOWN_ERROR;
+            }
         }
     }