From b1a3fdb99f5c577227fe80298f01bfbeb01322ad Mon Sep 17 00:00:00 2001
From: Yohei Yukawa <yukawa@google.com>
Date: Wed, 19 Dec 2018 14:12:42 -0800
Subject: [PATCH] Create /data/system/inputmethod/ directory lazily

With this CL, the directory /data/system/inputmethod/ is also created
only when necessary.  Also the /data/system/inputmethod/ will be
deleted automatically when it is empty.

There should be no developer-facing behavior change.

Bug: 121223050
Test: Manually verified as follows
  1. Build and flash aosp_taimen-userdebug into taimen
  2. Wait until the device fully boots up
  3. adb reboot  # to avoid Bug 121259290
  4. adb root
  5. adb shell cat /data/system/inputmethod/subtypes.xml
      -> make sure the content looks as follows:
         <subtypes>
           <imi id="com.android.inputmethod.latin/.LatinIME">
             <subtype ....>
             <subtype ....>
           </imi/>
         </subtypes>
  6. Open AOSP Keyboard settings
  7. Go to "Appearance & Layouts" -> "Custom input styles"
  8. Remove all layouts
  9. adb shell cat /data/system/inputmethod/subtypes.xml
      -> make sure the file no longer exists
 10. adb shell ls /data/system/inputmethod
      -> make sure the directory no longer exists
 11. Open AOSP Keyboard settings
 12. Go to "Appearance & Layouts" -> "Custom input styles"
 13. Add English (US) - Dvorak
 14. adb shell ls /data/system/inputmethod
      -> make sure the directory exists and only the system user can
         access it
Change-Id: I2307b5e4edf7b90d2fc03138f233d6051f80cf90
---
 .../inputmethod/InputMethodManagerService.java   | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
index 597d81ffab5c6..78dd2200f9a1c 100644
--- a/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -73,6 +73,7 @@ import android.os.Binder;
 import android.os.Bundle;
 import android.os.Debug;
 import android.os.Environment;
+import android.os.FileUtils;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.IInterface;
@@ -4299,9 +4300,6 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
                     ? new File(Environment.getDataDirectory(), SYSTEM_PATH)
                     : Environment.getUserSystemDirectory(userId);
             final File inputMethodDir = new File(systemDir, INPUT_METHOD_PATH);
-            if (!inputMethodDir.exists() && !inputMethodDir.mkdirs()) {
-                Slog.w(TAG, "Couldn't create dir.: " + inputMethodDir.getAbsolutePath());
-            }
             final File subtypeFile = new File(inputMethodDir, ADDITIONAL_SUBTYPES_FILE_NAME);
             mAdditionalInputMethodSubtypeFile = new AtomicFile(subtypeFile, "input-subtypes");
             readAdditionalInputMethodSubtypes(mAdditionalSubtypesMap,
@@ -4349,6 +4347,18 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
                 if (subtypesFile.exists()) {
                     subtypesFile.delete();
                 }
+                final File parentDir = subtypesFile.getBaseFile().getParentFile();
+                if (parentDir != null && FileUtils.listFilesOrEmpty(parentDir).length == 0) {
+                    if (!parentDir.delete()) {
+                        Slog.e(TAG, "Failed to delete the empty parent directory " + parentDir);
+                    }
+                }
+                return;
+            }
+
+            final File parentDir = subtypesFile.getBaseFile().getParentFile();
+            if (!parentDir.exists() && !parentDir.mkdirs()) {
+                Slog.e(TAG, "Failed to create a parent directory " + parentDir);
                 return;
             }