Ensure the resource name is validated

According to the comment of FabricatedOverlaysTests#setResourcesValue,
it describes that the param `resourceName` should be in the form
"[package]:type/entry". However, there is no validation for it.

This patch adds the function ensureValidResourceName to validate the
input param resourceName.

Bug: 205919743

Test: atest OverlayDeviceTests
      # result is http://ab/I87000010106296791

Change-Id: I3327feafe297b697ae295e7a417cba581c482726

core/java/android/content/om/FabricatedOverlay.java

@@ -26,6 +26,7 @@ import android.text.TextUtils;
 import com.android.internal.util.Preconditions;
 
 import java.util.ArrayList;
+import java.util.Objects;
 
 /**
  * Fabricated Runtime Resource Overlays (FRROs) are overlays generated ar runtime.
@@ -88,6 +89,27 @@ public class FabricatedOverlay {
             return this;
         }
 
+        /**
+         * Ensure the resource name is in the form [package]:type/entry.
+         *
+         * @param name name of the target resource to overlay (in the form [package]:type/entry)
+         * @return the valid name
+         */
+        private static String ensureValidResourceName(@NonNull String name) {
+            Objects.requireNonNull(name);
+            final int slashIndex = name.indexOf('/'); /* must contain '/' */
+            final int colonIndex = name.indexOf(':'); /* ':' should before '/' if ':' exist */
+
+            // The minimum length of resource type is "id".
+            Preconditions.checkArgument(
+                    slashIndex >= 0 /* It must contain the type name */
+                    && colonIndex != 0 /* 0 means the package name is empty */
+                    && (slashIndex - colonIndex) > 2 /* The shortest length of type is "id" */,
+                    "\"%s\" is invalid resource name",
+                    name);
+            return name;
+        }
+
         /**
          * Sets the value of the fabricated overlay
          *
@@ -99,6 +121,8 @@ public class FabricatedOverlay {
          * @see android.util.TypedValue#type
          */
         public Builder setResourceValue(@NonNull String resourceName, int dataType, int value) {
+            ensureValidResourceName(resourceName);
+
             final FabricatedOverlayInternalEntry entry = new FabricatedOverlayInternalEntry();
             entry.resourceName = resourceName;
             entry.dataType = dataType;
@@ -120,6 +144,8 @@ public class FabricatedOverlay {
          */
         public Builder setResourceValue(@NonNull String resourceName, int dataType, int value,
                 String configuration) {
+            ensureValidResourceName(resourceName);
+
             final FabricatedOverlayInternalEntry entry = new FabricatedOverlayInternalEntry();
             entry.resourceName = resourceName;
             entry.dataType = dataType;
@@ -140,6 +166,8 @@ public class FabricatedOverlay {
          * @see android.util.TypedValue#type
          */
         public Builder setResourceValue(@NonNull String resourceName, int dataType, String value) {
+            ensureValidResourceName(resourceName);
+
             final FabricatedOverlayInternalEntry entry = new FabricatedOverlayInternalEntry();
             entry.resourceName = resourceName;
             entry.dataType = dataType;
@@ -161,6 +189,8 @@ public class FabricatedOverlay {
          */
         public Builder setResourceValue(@NonNull String resourceName, int dataType, String value,
                 String configuration) {
+            ensureValidResourceName(resourceName);
+
             final FabricatedOverlayInternalEntry entry = new FabricatedOverlayInternalEntry();
             entry.resourceName = resourceName;
             entry.dataType = dataType;
@@ -180,6 +210,8 @@ public class FabricatedOverlay {
          */
         public Builder setResourceValue(@NonNull String resourceName, ParcelFileDescriptor value,
                 String configuration) {
+            ensureValidResourceName(resourceName);
+
             final FabricatedOverlayInternalEntry entry = new FabricatedOverlayInternalEntry();
             entry.resourceName = resourceName;
             entry.binaryData = value;

core/tests/overlaytests/device/src/com/android/overlaytest/FabricatedOverlaysTest.java

@@ -18,7 +18,6 @@ package com.android.overlaytest;
 
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
-import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertFalse;
 import static org.testng.Assert.assertNull;
 import static org.testng.Assert.assertThrows;
@@ -45,7 +44,6 @@ import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 import java.util.Collections;
-import java.util.List;
 import java.util.concurrent.TimeoutException;
 
 @RunWith(JUnit4.class)
@@ -220,12 +218,57 @@ public class FabricatedOverlaysTest {
         }
     }
 
+    @Test
+    public void setResourceValue_withNullResourceName() throws Exception {
+        final FabricatedOverlay.Builder builder = new FabricatedOverlay.Builder(
+                "android", TEST_OVERLAY_NAME, mContext.getPackageName());
+
+        assertThrows(NullPointerException.class,
+                () -> builder.setResourceValue(null, TypedValue.TYPE_INT_DEC, 1));
+    }
+
+    @Test
+    public void setResourceValue_withEmptyResourceName() throws Exception {
+        final FabricatedOverlay.Builder builder = new FabricatedOverlay.Builder(
+                "android", TEST_OVERLAY_NAME, mContext.getPackageName());
+
+        assertThrows(IllegalArgumentException.class,
+                () -> builder.setResourceValue("", TypedValue.TYPE_INT_DEC, 1));
+    }
+
+    @Test
+    public void setResourceValue_withEmptyPackageName() throws Exception {
+        final FabricatedOverlay.Builder builder = new FabricatedOverlay.Builder(
+                "android", TEST_OVERLAY_NAME, mContext.getPackageName());
+
+        assertThrows(IllegalArgumentException.class,
+                () -> builder.setResourceValue(":color/mycolor", TypedValue.TYPE_INT_DEC, 1));
+    }
+
+    @Test
+    public void setResourceValue_withInvalidTypeName() throws Exception {
+        final FabricatedOverlay.Builder builder = new FabricatedOverlay.Builder(
+                "android", TEST_OVERLAY_NAME, mContext.getPackageName());
+
+        assertThrows(IllegalArgumentException.class,
+                () -> builder.setResourceValue("c/mycolor", TypedValue.TYPE_INT_DEC, 1));
+    }
+
+    @Test
+    public void setResourceValue_withEmptyTypeName() throws Exception {
+        final FabricatedOverlay.Builder builder = new FabricatedOverlay.Builder(
+                "android", TEST_OVERLAY_NAME, mContext.getPackageName());
+
+        assertThrows(IllegalArgumentException.class,
+                () -> builder.setResourceValue("/mycolor", TypedValue.TYPE_INT_DEC, 1));
+    }
+
     @Test
     public void testInvalidResourceValues() throws Exception {
         final FabricatedOverlay overlay = new FabricatedOverlay.Builder(
                 "android", TEST_OVERLAY_NAME, mContext.getPackageName())
                 .setResourceValue(TEST_RESOURCE, TypedValue.TYPE_INT_DEC, 1)
-                .setResourceValue("something", TypedValue.TYPE_INT_DEC, 1)
+                .setResourceValue("color/something", TypedValue.TYPE_INT_DEC, 1)
                 .build();
 
         waitForResourceValue(0);