From 28e96db99fd1589e60ac1e7a71f4cfaff4d44147 Mon Sep 17 00:00:00 2001
From: Iain Patterson <me@iain.cx>
Date: Wed, 20 Apr 2016 15:36:02 +0100
Subject: [PATCH] Restore environment variables when becoming.

Environment variables listed in .become/environment/user will be passed
to the sudo shell.
---
 opt/bin/become | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/opt/bin/become b/opt/bin/become
index d958646..4b1c0dc 100755
--- a/opt/bin/become
+++ b/opt/bin/become
@@ -59,6 +59,29 @@ for candidate in "$HOME" "$PROFILE_HOME"; do
   [ -f "$userprofile" ] || userprofile=
 done
 
+# Preserve environment variables.
+ignore_environment_user=0
+for candidate in "$HOME" "$PROFILE_HOME"; do
+  [ -n "$candidate" ] || continue
+  BECOME="$candidate/.become/environment"
+  [ -d "$BECOME" ] || continue
+
+  # Script to run when becoming any user.
+  [ -z "$allusersenvironment" ] && allusersenvironment="$BECOME/all"
+  [ -f "$allusersenvironment" ] || allusersenvironment=
+
+  # Set $HOME/all sticky to ignore $PROFILE_HOME/$user.
+  if [ "$candidate" = "$HOME" ]; then
+    [ -k "$BECOME/all" ] && ignore_environment_user=1
+  else
+    [ $ignore_environment_user = 1 ] && continue
+  fi
+
+  # Environment variables to preserve when becomeing this user.
+  [ -z "$userenvironment" ] && userenvironment="$BECOME/$user"
+  [ -f "$userenvironment" ] || userenvironment=
+done
+
 file="${TMPDIR:-/tmp}/$USER.become.$user.$RANDOM.$$"
 umask=$(builtin umask -p)
 builtin umask 077
@@ -93,8 +116,16 @@ else
 fi
 
 echo >&3 ". ${PROFILE_HOME:-$HOME}/.bash_profile"
-[ -f "$allusersprofile" ] && cat >&3 2>/dev/null "$allusersprofile"
-[ -f "$userprofile" ] && cat >&3 2>/dev/null "$userprofile"
+for profile in "$allusersprofile" "$userprofile"; do
+  [ -f "$profile" ] && cat >&3 2>/dev/null "$profile"
+done
+for environment in "$allusersenvironment" "$userenvironment"; do
+  [ -f "$environment" ] || continue
+  while read -d $'\n' variable; do
+    variable=${variable%%=*}
+    eval "[ -z \${$variable:+set} ] || echo >&3 \"$variable='\$$variable'\""
+  done < "$environment"
+done
 [ $chdir = 1 ] && echo >&3 2>/dev/null "cd - &>/dev/null"
 
 exec 3>&-
-- 
2.7.4