[gentoo-dev] [PATCH 3/4] acct-user.eclass: use an eclass variable for the override variable name

[Michael Orlitzky <mjo@gentoo.org>]

If (after upcasing and replacing hyphens by underscores) ACCT_USER_NAME
is set to something that isn't valid in a bash variable name, the eclass
will crash: it uses ACCT_USER_NAME to construct the make.conf override
variables in pkg_pretend() and src_install().

This commit relocates the computation of the "override name" subsequent
to the definition of ACCT_USER_NAME="${PN}". In Gentoo, policy prohibits
redefinition of that variable; so nothing is changed. But in an overlay,
this allows the ebuild to define ACCT_USER_NAME to something that would
not be valid in a bash variable at the expense of violating expectations
about the override variable names.

Signed-off-by: Michael Orlitzky <mjo@gentoo.org>
---
 eclass/acct-user.eclass | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/eclass/acct-user.eclass b/eclass/acct-user.eclass
index a4fe5e9f5e34..fb3ccd2044da 100644
--- a/eclass/acct-user.eclass
+++ b/eclass/acct-user.eclass
@@ -64,6 +64,23 @@ inherit user-info
 # package naming restrictions would prohibit some otherwise-valid usernames.
 ACCT_USER_NAME=${PN}
 
+# @ECLASS_VARIABLE: _OVERRIDE_NAME
+# @INTERNAL
+# @DESCRIPTION:
+# A version of the user name suitable for use in a bash variable. This
+# is used to construct the names of the make.conf override variables and
+# it will always be uppercase $PN with the hyphens replaced by
+# underscores. It is defined once, here, so that in an overlay the
+# ebuild may set ACCT_USER_NAME to something other than $PN without
+# affecting the name of the override variable. This is necessary if the
+# username in question would lead to an invalid bash variable
+# name. Doing so does violate expectations with respect to the override
+# naming convention, but (a) your warranty is already void if you are
+# changing ACCT_USER_NAME or using make.conf overrides, and (b) you
+# shouldn't need make.conf overrides in an overlay.
+_OVERRIDE_NAME=${ACCT_USER_NAME^^}
+_OVERRIDE_NAME=${_OVERRIDE_NAME//-/_}
+
 # @ECLASS_VARIABLE: ACCT_USER_ID
 # @REQUIRED
 # @DESCRIPTION:
@@ -231,8 +248,7 @@ acct-user_pkg_pretend() {
 	local user_id=${ACCT_USER_ID}
 
 	# check for the override
-	local override_name=${ACCT_USER_NAME^^}
-	local override_var=ACCT_USER_${override_name//-/_}_ID
+	local override_var=ACCT_USER_${_OVERRIDE_NAME}_ID
 	if [[ -n ${!override_var} ]]; then
 		user_id=${!override_var}
 		[[ ${user_id} -ge -1 ]] || die "${override_var}=${user_id} invalid!"
@@ -274,11 +290,9 @@ acct-user_src_install() {
 	local ACCT_USER_GROUPS=${ACCT_USER_GROUPS[*]}
 
 	# support make.conf overrides
-	local override_name=${ACCT_USER_NAME^^}
-	override_name=${override_name//-/_}
 	local var
 	for var in ACCT_USER_{ID,COMMENT,SHELL,HOME{,_OWNER,_PERMS},GROUPS}; do
-		local var_name=ACCT_USER_${override_name}_${var#ACCT_USER_}
+		local var_name=ACCT_USER_${_OVERRIDE_NAME}_${var#ACCT_USER_}
 		if [[ -n ${!var_name} ]]; then
 			ewarn "${var_name}=${!var_name} override in effect, support will not be provided."
 		else
@@ -286,7 +300,7 @@ acct-user_src_install() {
 		fi
 		declare -g "_${var}=${!var_name}"
 	done
-	var_name=ACCT_USER_${override_name}_GROUPS_ADD
+	var_name=ACCT_USER_${_OVERRIDE_NAME}_GROUPS_ADD
 	if [[ -n ${!var_name} ]]; then
 		ewarn "${var_name}=${!var_name} override in effect, support will not be provided."
 		_ACCT_USER_GROUPS+=" ${!var_name}"
@@ -436,12 +450,10 @@ acct-user_pkg_postinst() {
 		has "${g}" "${groups[@]}" || del_groups+="${del_groups:+, }${g}"
 	done
 	if [[ -n ${del_groups} ]]; then
-		local override_name=${ACCT_USER_NAME^^}
-		override_name=${override_name//-/_}
 		ewarn "Removing user ${ACCT_USER_NAME} from group(s): ${del_groups}"
 		ewarn "To retain the user's group membership in the local system"
-		ewarn "config, override with ACCT_USER_${override_name}_GROUPS or"
-		ewarn "ACCT_USER_${override_name}_GROUPS_ADD in make.conf."
+		ewarn "config, override with ACCT_USER_${_OVERRIDE_NAME}_GROUPS or"
+		ewarn "ACCT_USER_${_OVERRIDE_NAME}_GROUPS_ADD in make.conf."
 		ewarn "Documentation reference:"
 		ewarn "https://wiki.gentoo.org/wiki/Practical_guide_to_the_GLEP_81_migration#Override_user_groups"
 	fi
-- 
2.43.2