[gentoo-dev] [PATCH] python-utils-r1.eclass: python_export_utf8_locale(), ensure sane locale

["Michał Górny" <mgorny@gentoo.org>]

Ensure that the locale selected by python_export_utf8_locale() conforms
to POSIX-ish case conversions. Otherwise, we may accidentally force
a locale that will break random ebuilds and programs.
---
 eclass/python-utils-r1.eclass | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/eclass/python-utils-r1.eclass b/eclass/python-utils-r1.eclass
index 6ff1dd1..5e3338f 100644
--- a/eclass/python-utils-r1.eclass
+++ b/eclass/python-utils-r1.eclass
@@ -1141,6 +1141,24 @@ python_fix_shebang() {
 	done
 }
 
+# @FUNCTION: _python_check_locale_sanity
+# @USAGE: <locale>
+# @RETURN: 0 if sane, 1 otherwise
+# @DESCRIPTION:
+# Check whether the specified locale sanely maps between lowercase
+# and uppercase ASCII characters.
+_python_check_locale_sanity() {
+	local -x LC_CTYPE=${1}
+	local IFS=
+
+	local lc=( {a..z} )
+	local uc=( {A..Z} )
+	local input=${lc[*]}${uc[*]}
+
+	local output=$(tr '[:lower:][:upper:]' '[:upper:][:lower:]' <<<"${input}")
+	[[ ${output} == "${uc[*]}${lc[*]}" ]]
+}
+
 # @FUNCTION: python_export_utf8_locale
 # @RETURN: 0 on success, 1 on failure.
 # @DESCRIPTION:
@@ -1165,8 +1183,10 @@ python_export_utf8_locale() {
 
 		for lang in ${locales}; do
 			if [[ $(LC_CTYPE=${lang} locale charmap 2>/dev/null) == UTF-8 ]]; then
-				export LC_CTYPE=${lang}
-				return 0
+				if _python_check_locale_sanity "${lang}"; then
+					export LC_CTYPE=${lang}
+					return 0
+				fi
 			fi  
 		done
 
-- 
2.6.3