Bug 27996

Summary:	setlocale should fail if the required gconv module is missing
Product:	glibc	Reporter:	Florian Weimer <fweimer>
Component:	locale	Assignee:	Siddhesh Poyarekar <siddhesh>
Status:	NEW ---
Severity:	normal	CC:	carlos, fweimer, siddhesh, victor.stinner
Priority:	P2	Flags:	fweimer: security-
Version:	unspecified
Target Milestone:	---
See Also:	https://bugzilla.redhat.com/show_bug.cgi?id=1973663
Host:		Target:
Build:		Last reconfirmed:
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Description Florian Weimer 2021-06-18 14:29:49 UTC

setlocale succeeds:

$ LC_ALL=lv_LV locale
LANG=
LC_CTYPE="lv_LV"
LC_NUMERIC="lv_LV"
LC_TIME="lv_LV"
LC_COLLATE="lv_LV"
LC_MONETARY="lv_LV"
LC_MESSAGES="lv_LV"
LC_PAPER="lv_LV"
LC_NAME="lv_LV"
LC_ADDRESS="lv_LV"
LC_TELEPHONE="lv_LV"
LC_MEASUREMENT="lv_LV"
LC_IDENTIFICATION="lv_LV"
LC_ALL=lv_LV

The locale uses a somewhat unusual charset:

# LC_ALL=lv_LV locale -k charmap
charmap="ISO-8859-13"

But the charset is not installed:

# iconv -f UTF-8 -t ISO-8859-13
iconv: failed to start conversion processing

So mbstowcs fails to work.

Pointed out by Victor Stinner here: https://bugzilla.redhat.com/show_bug.cgi?id=1973663#c11

Comment 1 Carlos O'Donell 2021-06-18 19:49:29 UTC

I agree setlocale should fail in this case.

Comment 2 Siddhesh Poyarekar 2021-06-30 08:57:47 UTC

Calling locale that way does not actually call setlocale().  I've got a test with a patch which does; sending soon.

Comment 3 Florian Weimer 2022-02-21 11:20:25 UTC

It may be prudent to turn ISO-8859-1 and ISO-8859-15 into internal converts, too, so that we don't encounter additional overhead due to early converter loading for these (somewhat common) character sets.