Bug 1196566

Summary:	IFS incorrectly splitting herestrings in bash 4.2
Product:	Red Hat Enterprise Linux 7	Reporter:	Ian Wienand <iwienand>
Component:	bash	Assignee:	Ondrej Oprala <ooprala>
Status:	CLOSED ERRATA	QA Contact:	Martin Kyral <mkyral>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.3	CC:	isenfeld, ovasik
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	bash-4.2.46-14.el7	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	1250070 (view as bug list)		Environment:
Last Closed:	2015-11-19 04:39:47 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Ian Wienand 2015-02-26 10:10:10 UTC

We hit this problem in devstack [1] and maybe it is worth a backport?

consider

---
foo="hello,there"

IFS=, read hello there <<< $foo

echo $hello
echo "---"
echo $there
echo "---"
---

this ends up outputting

hello there
---

---

on bash-4.2.  after some digging, the best reference is [2] .  To quote from it

---
The bug is that the here string appears to undergo partial splitting using the "leaked" value of IFS being passed to read. As a result, the string becomes hello world, but is still seen by read as a single word. Since that word does not contain a :, read does not split it into two words, and the entire string is assigned to var1.
---

Thus quoting "$foo" above works around this, but it is a issue when trying to write portable shell scripts

[1] https://review.openstack.org/#/c/159366
[2] http://stackoverflow.com/questions/20144593/trying-to-split-a-string-into-two-variables

Comment 1 Ian Wienand 2015-02-26 10:11:53 UTC

I should note here that this is fixed in 4.3

Comment 2 Ondrej Oprala 2015-02-26 12:25:01 UTC

Hmm thanks for the report, I'll look at it, shouldn't be hard to backport.

Comment 10 errata-xmlrpc 2015-11-19 04:39:47 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-2144.html