Imghdr doesnt recognise some jpeg

[pierrechopin]

BPO	37629
Nosy	@vstinner, @kmoza, @pierrechopin
PRs	gh-60716: Update judgment method for jpeg. #15955
Files	e2006bd7-51d7-4554-9738-ea13207fd104.jpg cpython_imghdr_issue.txt

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2019-07-19.14:21:41.643>
created_at = <Date 2019-07-19.09:50:28.427>
labels = ['3.7', 'type-bug', 'library']
title = 'Imghdr doesnt recognise some jpeg'
updated_at = <Date 2019-09-11.14:00:27.538>
user = 'https://github.com/pierrechopin'

bugs.python.org fields:

activity = <Date 2019-09-11.14:00:27.538>
actor = 'python-dev'
assignee = 'none'
closed = True
closed_date = <Date 2019-07-19.14:21:41.643>
closer = 'pchopin'
components = ['Library (Lib)']
creation = <Date 2019-07-19.09:50:28.427>
creator = 'pchopin'
dependencies = []
files = ['48491', '48492']
hgrepos = []
issue_num = 37629
keywords = []
message_count = 4.0
messages = ['348161', '348171', '348173', '348179']
nosy_count = 3.0
nosy_names = ['vstinner', 'Krishna Oza', 'pchopin']
pr_nums = ['15955']
priority = 'normal'
resolution = 'duplicate'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue37629'
versions = ['Python 3.7']

[pierrechopin]

the imghdr library only checks for the presence of (b'JFIF', b'Exif') in the header, which is excluding some valid JPEG file. This is an example of not recognised ile

[kmoza]

The documentation at https://docs.python.org/3/library/imghdr.html?highlight=imghdr#module-imghdr says that JPEG files with JPEG data in JFIF or Exif formats are only supported as of now. Pierre Chopin could help with what format of jpeg you have uploaded.

[kmoza]

Victor
I have debugged the issue and found that the jpg file shared doesnt have the information in its header to identify the file format of this file.
The imghdr module needs file format information in first 32 bytes when the jpg file is read in binary mode. However for the file "e2006bd7-51d7-4554-9738-ea13207fd104.jpg" there is no such information present and hence I would like to suggest that the issue be closed appropriately.

P.S. Attaching the dump of file "e2006bd7-51d7-4554-9738-ea13207fd104.jpg" when read in binary mode.

[pierrechopin]

This is actually a duplicate of bpo-16512, i am closing this.