Merge branch 'master' of github.com:NixOS/nix

doc/manual/installation/installing-binary.xml

@@ -26,6 +26,14 @@ $ mkdir /nix
 $ chown alice /nix
 </screen>
 
+The install script will modify the first writable file from amongst
+<filename>.bash_profile</filename>, <filename>.bash_login</filename>
+and <filename>.profile</filename> to source
+<filename>~/.nix-profile/etc/profile.d/nix.sh</filename>. You can set
+the <command>NIX_INSTALLER_NO_MODIFY_PROFILE</command> environment
+variable before executing the install script to disable this
+behaviour.
+
 </para>
 
 <!--

scripts/install-nix-from-closure.sh

@@ -89,11 +89,13 @@ if [ -z "$_NIX_INSTALLER_TEST" ]; then
     $nix/bin/nix-channel --update nixpkgs
 fi
 
-# Make the shell source nix.sh during login.
-p=$HOME/.nix-profile/etc/profile.d/nix.sh
-
 added=
-for i in .bash_profile .bash_login .profile; do
+if [ -z "$NIX_INSTALLER_NO_MODIFY_PROFILE" ]; then
+
+    # Make the shell source nix.sh during login.
+    p=$HOME/.nix-profile/etc/profile.d/nix.sh
+
+    for i in .bash_profile .bash_login .profile; do
         fn="$HOME/$i"
         if [ -w "$fn" ]; then
             if ! grep -q "$p" "$fn"; then
@@ -103,7 +105,9 @@ for i in .bash_profile .bash_login .profile; do
             added=1
             break
         fi
-done
+    done
+
+fi
 
 if [ -z "$added" ]; then
     cat >&2 <<EOF