Bug#849638: diffoscope 66 does binary diff on APK files

[Hans-Christoph Steiner]

Reiner Herrmann:
> On Thu, Dec 29, 2016 at 12:41:16PM +0100, Hans-Christoph Steiner wrote:
>> When running diffoscope on two APKs using version 66, it now just does a
>> straight binary comparison of the direct file itself.  Running
>> diffoscope 64 generated a nice output of the individual files in the ZIP
>> (an APK is a signed JAR with some other special features). Attached is
>> the output from v66.  You can find v64 output here:
>>
>> http://37.218.242.117/
>>
>> You can download these two APKs to test with from here:
>>
>> http://37.218.242.117/aarddict.android_26.apk
>> https://f-droid.org/repo/aarddict.android_26.apk
> 
> Just had a short look at this. The reason is that file/libmagic detects
> the files differently:
> 
> $ file 1/aarddict.android_26.apk 2/aarddict.android_26.apk 
> 1/aarddict.android_26.apk: Java archive data (JAR)
> 2/aarddict.android_26.apk: Zip archive data, at least v2.0 to extract
> 
> So the APK comparator should probably also work on files detected as zip.
> 

Yeah, that makes sense as long as libmagic cannot reliably detect APKs
vs JAR vs ZIP.