From d3bfbc6a20d0eb27266a26356a87ae5a2d19584c Mon Sep 17 00:00:00 2001
From: Neil Fuller <nfuller@google.com>
Date: Mon, 30 May 2022 16:35:32 +0100
Subject: [PATCH] Add support for "empty" server-side flag values

Add support to ServerFlags for a special escape string for empty arrays.
Also adjust code to allow no entries in the "origin priorities" to help
test what happens when auto time isn't supported (see the associated
change in packages/apps/Settings/

Tested with:

adb shell cmd dumpsys time_detector
<Inspect the ConfigurationInternal>
<View SettingsUI Date & Time screen>

adb shell cmd device_config system_time time_detector_origin_priorities_override _[]_

adb shell cmd dumpsys time_detector
<Inspect the ConfigurationInternal>
<View SettingsUI Date & Time screen>

Bug: 172891783
Test: See above
Change-Id: I1e2573384055b2527f39b0134ace5f08019a3a40
---
 .../android/server/timedetector/ServerFlags.java   | 14 +++++++++++---
 .../timedetector/ServiceConfigAccessorImpl.java    |  2 +-
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/services/core/java/com/android/server/timedetector/ServerFlags.java b/services/core/java/com/android/server/timedetector/ServerFlags.java
index 417177fa903ef..773b5175c954b 100644
--- a/services/core/java/com/android/server/timedetector/ServerFlags.java
+++ b/services/core/java/com/android/server/timedetector/ServerFlags.java
@@ -278,11 +278,19 @@ public final class ServerFlags {
      */
     @NonNull
     public Optional<String[]> getOptionalStringArray(@DeviceConfigKey String key) {
-        Optional<String> string = getOptionalString(key);
-        if (!string.isPresent()) {
+        Optional<String> optionalString = getOptionalString(key);
+        if (!optionalString.isPresent()) {
             return Optional.empty();
         }
-        return Optional.of(string.get().split(","));
+
+        // DeviceConfig appears to have no way to specify an empty string, so we use "_[]_" as a
+        // special value to mean a zero-length array.
+        String value = optionalString.get();
+        if ("_[]_".equals(value)) {
+            return Optional.of(new String[0]);
+        }
+
+        return Optional.of(value.split(","));
     }
 
     /**
diff --git a/services/core/java/com/android/server/timedetector/ServiceConfigAccessorImpl.java b/services/core/java/com/android/server/timedetector/ServiceConfigAccessorImpl.java
index b161cc7204585..e4f3a80c03b5c 100644
--- a/services/core/java/com/android/server/timedetector/ServiceConfigAccessorImpl.java
+++ b/services/core/java/com/android/server/timedetector/ServiceConfigAccessorImpl.java
@@ -334,7 +334,7 @@ final class ServiceConfigAccessorImpl implements ServiceConfigAccessor {
                 }
 
                 int[] priorityInts = null;
-                if (priorityStrings != null && priorityStrings.length > 0) {
+                if (priorityStrings != null) {
                     priorityInts = new int[priorityStrings.length];
                     try {
                         for (int i = 0; i < priorityInts.length; i++) {