0000554: .eml file identified as text/html (should be message/rfc822) when "Subject:" header is first - MantisBT

ID	Project	Category	View Status	Date Submitted	Last Update

0000554	file	General	public	2024-08-25 06:48	2024-08-25 13:30

Reporter	Slush9	Assigned To
Priority	normal	Severity	minor	Reproducibility	always
Status	new	Resolution	open
Platform	Linux	OS	Debian	OS Version	12
Product Version	5.44

Summary	0000554: .eml file identified as text/html (should be message/rfc822) when "Subject:" header is first
Description	Hi, I have a .eml file generated by Apple Mail which seems to fully conform to RFC 5322 but is being identified by file-5.44 as text/html: $ file --mime-type Re_\ We\'ve\ made\ changes\ to\ your\ bill.eml Re_ We've made changes to your bill.eml: text/html $ file -v file-5.44 magic file from /etc/magic:/usr/share/misc/magic I've determined that the false identification is caused by the fact that the first header in the file is a "Subject:" header: $ head -1 Re_\ We\'ve\ made\ changes\ to\ your\ bill.eml Subject: Re: We've made changes to your bill If I move the "Date:" header to the top and run the command again, I get the expected identification: $ head -1 Re_\ We\'ve\ made\ changes\ to\ your\ bill.eml Date: Mon, 18 Dec 2023 23:34:30 +1100 $ file --mime-type Re_\ We\'ve\ made\ changes\ to\ your\ bill.eml Re_ We've made changes to your bill.eml: message/rfc822 False identifications also occur for these headers when first-billed:
Additional Information	Out of all the headers in this particular email, only "Date:" and "From:" cause `file` to correctly identify the file as message/rfc822, and only when one of those is first-billed. Any of the other headers in this email: - Cc: - Content-Type: - In-Reply-To: - Message-Id: - Mime-Version: - References: - Subject: - To: - X-Apple-Base-Url: - X-Apple-Mail-Remote-Attachments: - X-Apple-Mail-Signature: - X-Apple-Windows-Friendly: - X-Uniform-Type-Identifier: - X-Universally-Unique-Identifier: if first-billed, cause the file to be misidentified as either text/html or text/plain. I appreciate that it wouldn't be possible for the libmagic maintainers to predict every possible first header in a .eml file, but "To:", "Cc:", and "Subject:" are all highly prevalent and should perhaps be checked.
Tags	No tags attached.

Date Modified	Username	Field	Change
2024-08-25 06:48	Slush9	New Issue