I've had an issue reported by users on the Jenkins system I've installed at my new company. When downloading release files with the extension ".tgz" (tar'd gzip'd files from Linux), these files are having their file extension renamed to ".gz" by MS Internet Explorer and Edge browsers when we download them.
I've reproduced this on IE. If you just left-click on the download link, it automatically and silently renames the file it downloads to ".gz". If you right-click and select "Save target as", the default extension is ".gz". I don't have anything with Edge, but I've no reason to doubt the report.
I did some investigation to see whether I could narrow it down...
I wondered if this was an issue with the Nginx reverse proxy doing something strange with MIME types, so I turned off the Nginx service and pointed IE at "http://my.internal.jenkins.server:8080" (not the real name of the link, of course, but you can't see it because it's behind our firewall). Again though, IE saved the ".tgz" files with extension ".gz".
I wondered if it was an issue with Jenkins, so I went looking for another file to download. Downloading a Moodle release as tgz, again I get it saved with extension ".gz". So it seems to be a general issue with the browser, not with my Jenkins server.
Edit: Repeated this with files from other locations online...
- https://varnish-cache.org/_downloads/varnish-5.2.1.tgz downloads correctly on Edge.
- https://www.arb-silva.de/fileadmin/silva_databases/qiime/Silva_104_release.tgz downloads correctly on Edge.
- https://files.zimbra.com/downloads/8.6.0_GA/zcs-patch-8.6.0_GA_1162.tgz downloads correctly on Edge.
- https://www.coin-or.org/download/source/Ipopt/Ipopt-3.3.3.tgz does not download correctly on Edge.
- http://www.netlib.org/lapack/lapack-3.7.0.tgz does not download correctly on Edge.
- http://gmsh.info/src/gmsh-1.49.0-source.tgz does not download correctly on Edge.
I've tried the same thing on Chrome (on Windows) and Firefox (on Ubuntu). Both download the ".tgz" file correctly. So it seems to be specific to MS browsers.
Selecting "Copy shortcut", the URL definitely finishes ".tgz". Even if you download the file and let IE rename it to ".gz", if you go to the "Downloads" list and check the link, again it reports the URL is ".tgz".
The file content is unchanged. Changing the name back when downloading, or renaming the file after downloading, it works fine.
I've hit Google, of course. The following are the closest I've found, but they don't seem to have a solution.
This is not an issue I noticed with the Jenkins setup at my previous company. That said though, at my previous company we had a policy of using Chrome or Firefox in preferences to IE, so it's entirely possible that the issue existed there and we just never noticed it. My real job is embedded software, so devops is not something I have deep skills in.
Does anyone have any insights into this, please?