Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox seems to add bytes to some cached items and the beginning and at the end. When I download and compare the source, it's different. Bug 1000338 occurs too

  • 5 cavab
  • 1 has this problem
  • 3 views
  • Last reply by FredMcD

more options

Some binary items cached by FF when viewed in a hex editor have 15 bytes added at the beginning, some bytes are added at the end and some bytes are scattered around the cached file. When I download the original file and compare the original file with the cached file, they differ in these added byte sequences. No application is launched that could have modified the cache files. What could be the problem? When I reload Firefox and open cache manager, I get bug 1000338 for these files. I'm not sure these two things are related though.

Some binary items cached by FF when viewed in a hex editor have 15 bytes added at the beginning, some bytes are added at the end and some bytes are scattered around the cached file. When I download the original file and compare the original file with the cached file, they differ in these added byte sequences. No application is launched that could have modified the cache files. What could be the problem? When I reload Firefox and open cache manager, I get bug 1000338 for these files. I'm not sure these two things are related though.

Chosen solution

Yes, it's gzipped. Since the binary content was already compressed, gzip just added some header and random bytes here and there.

Read this answer in context 👍 0

All Replies (5)

more options

Are you talking about; Bug 1000338 - nsICacheEntry.lastModified not properly implemented  ?

What is your computer system and Firefox?

Have you been having crashes? Please post them.

more options

FredMcD said

Are you talking about; Bug 1000338 - nsICacheEntry.lastModified not properly implemented  ?

Yes, but that's a minor issue for me. I wonder why some cache elements get corrupted. My FF version is 49.0.1. Windows 10 64bit. I had no crashes. I cleaned my cache several times.

more options

I just had an idea. Could it be that the file is transferred and stored compressed by gzip? Its content encoding is "gzip".

more options

Seçilmiş Həll

Yes, it's gzipped. Since the binary content was already compressed, gzip just added some header and random bytes here and there.

more options

That was very good work. Well done.