[BUG] temp file not being deleted when building

[MFinkBK]

Information

1. Apktool Version (apktool -version) - 2.6.0
2. Operating System (Mac, Linux, Windows) - Windows
3. APK From? (Playstore, ROM, Other) - probably not relevant

Steps to Reproduce

1. apktool b -o out extractedFolder
2. Monitor the %TEMP% folder; during build, two APKTOOL{longnumber}.tmp files are created, and one of the is removed again. The other stays there.

Note that this only occurs when (re-)building, not when decompiling an .apk. After digging a bit in the source, I suspect the following lines in buildManifest() to be the problem:

Apktool/brut.apktool/apktool-lib/src/main/java/brut/androlib/Androlib.java

Lines 548 to 549 in 9bdf385

	File apkFile = File.createTempFile("APKTOOL", null);
	apkFile.delete();

Here, the temporary file is being created and then deleted again (I guess to get the temp filename). Then the filename is used in a call to aaptPackage(), but afterwards it isn't deleted.

Note that buildResourcesFull() also creates a temp filename, but deletes the created file again in line 512, and that's the difference to buildManifest():

Apktool/brut.apktool/apktool-lib/src/main/java/brut/androlib/Androlib.java

Line 512 in 9bdf385

apkFile.delete();

[iBotPeaches]

Thanks for the research, I'll use this research and dig around in a bit and see what I can find.

[iBotPeaches]

Thanks, found em. PR is up.

[MFinkBK]

I just tested with the apktool .jar file built from the GitHub Action (the build artifact .jar named apktool-2.6.1-ddc4bb-SNAPSHOT-small.jar, from the run https://github.com/iBotPeaches/Apktool/actions/runs/1707904289). Unfortunately the code change doesn't fix the bug (yet). I have no skills in Java debugging, but I checked out what's logged in SysInternal's Process Monitor tool when a build runs. I attached the CSV export of the relevant log lines, here: apktool-procmon-logfile.csv

The APKTOOL.tmp file that isn't being removed is opened several times using Win32 API CreateFile(), which it seems is used for reading, writing, getting attributes from a file and even for deleting. The last CreateFile() call that should remove the file gets a Sharing Violation, so my guess is that some object still has a handle on the file. And there's a CreateFile call that isn't matched with a CloseFile call that may be the reason. From trying to match the calls to the code in buildResourcesFull(), my guess is that it's the call to new ExtFile() in this line that keeps the temp file open:

Apktool/brut.apktool/apktool-lib/src/main/java/brut/androlib/Androlib.java

Line 498 in 9bdf385

Directory tmpDir = new ExtFile(apkFile).getDirectory();

(I guess the GC at some point collects the object and closes the file, but the apkFile.delete() call happens earlier than that.

[iBotPeaches]

:(

Thanks will reopen.

[MFinkBK]

My guess is that something like that would help:

ExtFile apkFileExt = new ExtFile(apkFile);
Directory tmpDir = apkFileExt.getDirectory();
apkFileExt.close();

I'm not quite sure if there's another way to do that in Java.

[iBotPeaches]

Okay, next PR has to be perfect. I've done a looped build/decode of 10 applications 20 times and I have no files in /tmp. Additionally, scripted the actual building of Apktool 20 times and no /tmp files.

[MFinkBK]

I'd like to test the PR, but unfortunately the GitHub action doesn't provide a built apktool.jar, only when merged to master...

[MFinkBK]

Works! I tested with apktool-2.6.1-797fc3-SNAPSHOT-small.jar. Thanks for the effort to fix this bug, and for making apktool in the first place!