WebRequest Reader is not closed

[asmirnov]

Environment

The reader in AndroidWebRequest (​https://github.com/adblockplus/libadblockplus-android/blob/master/libadblockplus-android/src/org/adblockplus/libadblockplus/android/AndroidWebRequest.java#L138) is not closed after reading, allowing possible leak of internal reader buffer (up to 8192 bytes). The bug comes from original adblockplusandroid sources ​https://github.com/adblockplus/adblockplusandroid/blob/master/src/org/adblockplus/android/AndroidWebRequest.java#L92

It can be detected in StrictMode with

StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
      .detectAll()
      .penaltyLog()
      .penaltyDeath()
      .build());

and can be seen in the log:

10-12 14:19:26.899 5984-5999 E/StrictMode: A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks.
                                           java.lang.Throwable: Explicit termination method 'end' not called
                                               at dalvik.system.CloseGuard.open(CloseGuard.java:184)
                                               at java.util.zip.Inflater.<init>(Inflater.java:82)
                                               at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:103)
                                               at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:88)
                                               at org.adblockplus.libadblockplus.android.AndroidWebRequest.httpGET(AndroidWebRequest.java:137)
                                               at org.adblockplus.libadblockplus.android.AndroidWebRequestResourceWrapper.httpGET(AndroidWebRequestResourceWrapper.java:140)

Actually there is no serious leak as our files are text files and are read from the beginning to the end, but it would be better to fix it anyway. Note input stream is NOT leaked as it's closed in connection.disconnect() so it relates to reader only. Closing reader forces closing input stream (including GZIPInputStream).

How to reproduce

1. Enable strict mode (see the code above)
2. Clean app cache in order to force redownload subscriptions using WebRequest
3. Make sure you can see output in the log

...

Observed behaviour

Reader is not closed (and leaked).

Expected behaviour

Reader is closed, no log output.

[abpbot]

A commit referencing this issue has landed:
​Issue 5858 - WebRequest Reader is not closed

[abpbot]

A commit referencing this issue has landed:
​Issue 5858 - WebRequest Reader is not closed