- Fix issues in bashrc when sourced in a script (like the post-merge

git hook).
- Fix issue with failure to source bashrc in the post-merge git hook
(file not found issue).

.bashrc

@@ -7,7 +7,7 @@ export HISTCONTROL=ignoreboth:erasedups
 export HISTSIZE=100000
 export HISTFILESIZE=100000
 export PROMPT_COMMAND="history -a; $PROMPT_COMMAND"
-if [ -n "$BASH" ]
+if [ -n "${BASH:-}" ]
 then
     shopt -s histappend
     shopt -s checkwinsize
@@ -26,7 +26,7 @@ fi
 [ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"
 
 # set variable identifying the chroot you work in (used in the prompt below)
-if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
+if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
     debian_chroot=$(cat /etc/debian_chroot)
 fi
 

.githooks/post-merge

 #!/bin/sh
 set -eu
-. .bashrc
+cd "$(git rev-parse --show-toplevel)"
+. ./.bashrc
 gen-ssh-config