Bug 2029975

Summary:	Regression: file no longer detects javascript executables as application/javascript
Product:	[Fedora] Fedora	Reporter:	Miro Hrončok <mhroncok>
Component:	file	Assignee:	Vincent Mihalkovič <vmihalko>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	jkaluza, kdudka, odubaj, svashisht, vmihalko
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Fixed In Version:	file-5.41-2.fc36	Doc Type:	If docs needed, set a value
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Last Closed:	2021-12-08 15:07:14 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description Miro Hrončok 2021-12-07 17:38:05 UTC

Description of problem:
/usr/lib/node_modules/yarn/bin/yarn.js and other JavaScript files used to be detected as application/javascript in Fedora 34/35, but are detected as text/plain in Fedora 36.

Version-Release number of selected component:
file-5.41-1.fc36.x86_64

How reproducible: Easy

Steps to Reproduce:
1. mock -r fedora-36-x86_64 install yarnpkg file
2. mock -r fedora-36-x86_64 shell
3. file --mime-type /usr/lib/node_modules/yarn/bin/yarn.js

(You can also repeat with fedora-35-x86_64 for comparison.)

Actual results:
/usr/lib/node_modules/yarn/bin/yarn.js: text/plain

Expected results:
/usr/lib/node_modules/yarn/bin/yarn.js: application/javascript

Additional info:
I see no relevant notice in https://fossies.org/linux/misc/file-5.41.tar.gz/file-5.41/ChangeLog so I assume this is a regression.

Comment 1 Vincent Mihalkovič 2021-12-07 21:27:54 UTC

This regression was introduced with file-5.41-1.fc36, in file-5.40-9.fc35 JavaScript detection works as expected.

The problematic commit & line is https://github.com/file/file/commit/c07b2a18eb1c5d3854e3ecc72319a2336e361d9e#diff-85466710385fb2ac02303e18020a937c563abbea6d4050ba3aff96cf6c8e6866R100
This "wild-card match for interpreters" powerful (with huge strength) pattern is cause of the regression. After running file --checking-printout --list:

100: > 0 string/wt,=#! ,"a"]                                                <-- used detection pattern
101: >> 1 string,x,"%s script text executable"] 
...
16: > 0 search/1,=#!/usr/bin/env nodejs,"Node.js script text executable"]   <-- expected detection pattern

I'm going to ask the upstream about the proper fix for this - whether to increase the strength of the JavaScript detection patterns or to remove the "wild-card match for interpreters" pattern...

Comment 2 Vincent Mihalkovič 2021-12-08 15:07:14 UTC

upstream commit: https://github.com/file/file/commit/f687fa2b92cd923173126614516c1d07894affb3
dist-git commit: https://src.fedoraproject.org/rpms/file/c/0be129eb878837a656b8a990295103d446be01c9

Comment 3 Miro Hrončok 2021-12-08 15:13:56 UTC

That was fast. Thanks!