#ＩＮＴＲＯ
After digging up for a while I've found where the issue comes from for both
`.html` and `.py` (bug #1857824) files.
#ＳＨＯＲＴ
The culprit responsible for misidentification resides in `.xml` database which
specifies how to match mime-type against input data. It can be found here [2].
#ＬＯＮＧ
The `kmimetypefinder.cpp` pulls up [0] `QMimeDatabase db` apis by
`db.mimeTypeForFile(...)` which in turns bootstrup `QMimeDatabasePrivate ...`
XML database from .xml file.[1]
If we look carefully at the content of the `"text/x-perl"` entry we
would see the following:
```
<alias type="text/x-perl"/>
<magic priority="50">
...
<match value="use strict" type="string" offset="0:256"/>
...
</magic>
```
Did you notice the offset attribute `"0:256"`? Now if we run the
following two cases we will see that files whose content contains
keywords `use strict` in the range of 1..256 will be identified as
`text/x-perl` script and as `text/html` if the `use trict` is located
outside of such range otherwise, checkout:
💲 tee "index.html" <<eol ; echo -e "\n"; kmimetypefinder5 index.html
`printf "_"%.0s {1..256}`use strict
eol
application/x-perl # <- OUTPUT IS WRONG ⚠️
💲 tee "index.html" <<eol ; echo -e "\n"; kmimetypefinder5 index.html
`printf "_"%.0s {1..257}`use strict
eol
text/html # <- OUTPUT IS CORRECT!!! ✅ - Surprising, huh? 😏
#ＣＯＮＣＬＵＳＩＯＮ
This proves that the bug comes from QTBase database which wrongly identifies
`x-perl`'s keywords in JS scripts. The latter have `'use strict'` keyword that
specifically should be placed at the top of the script. It seems like that they
overlap for both languages. I think appropriate bug should be opened in the
QTBase bug registry.
[0]:
https://github.com/KDE/kde-cli-tools/blob/master/kmimetypefinder/kmimetypefinder.cpp
[1]:
https://github.com/qt/qtbase/blob/03dfd4199deb4a0f5123fb1eead42f7e1f85e9e3/src/corelib/mimetypes/qmimedatabase.cpp#L102
[2]:
https://github.com/qt/qtbase/tree/03dfd4199deb4a0f5123fb1eead42f7e1f85e9e3/src/corelib/mimetypes/mime/packages
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to shared-mime-info in
Ubuntu.
https://bugs.launchpad.net/bugs/1890716
Title:
misidentifies .html file as Perl script when it contains JavaScript
"use strict"
Status in shared-mime-info:
Unknown
Status in kde-cli-tools package in Ubuntu:
New
Status in shared-mime-info package in Ubuntu:
Fix Committed
Status in shared-mime-info package in Debian:
Confirmed
Bug description:
For .html files `xdg-mime` reports wrong type. The culprit is the
`"use strict"` phrase which is used in JavaScript. It should not
mistake .html files for anything else except of text/html !
STEPS TO REPRODUCE:
Run the following step by step in any folder:
1. $ echo "\"use strict\"" > index.html
2. $ xdg-mime query filetype index.html # -> application/x-perl - this should
be text/html!
Platform:
Ubuntu 20.04.1 LTS (Focal Fossa)"
Linux version 5.4.0-42-generic (buildd@lgw01-amd64-038) (gcc version 9.3.0
(Ubuntu 9.3.0-10ubuntu2))
xdg-utils: 1.1.3-2ubuntu1
To manage notifications about this bug go to:
https://bugs.launchpad.net/shared-mime-info/+bug/1890716/+subscriptions
--
Mailing list: https://launchpad.net/~touch-packages
Post to : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help : https://help.launchpad.net/ListHelp
