diff options
Diffstat (limited to 'lisp/env.el')
| -rw-r--r-- | lisp/env.el | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/lisp/env.el b/lisp/env.el index c2cf0888eb7..6de90385a35 100644 --- a/lisp/env.el +++ b/lisp/env.el @@ -68,10 +68,10 @@ with a character not a letter, digit or underscore; otherwise, enclose the entire variable name in braces. For instance, in `ab$cd-x', `$cd' is treated as an environment variable. -If WHEN-UNDEFINED is nil, references to undefined environment variables -are replaced by the empty string; if it is a function, the function is called -with the variable name as argument and should return the text with which -to replace it or nil to leave it unchanged. +If WHEN-UNDEFINED is omitted or nil, references to undefined environment +variables are replaced by the empty string; if it is a function, the +function is called with the variable's name as argument, and should return +the text with which to replace it, or nil to leave it unchanged. If it is non-nil and not a function, references to undefined variables are left unchanged. |