test: 07-variable-or-empty.

check.sh

@@ -45,6 +45,7 @@ tests='
 07-variable-or-slash
 07-variable-or-variable
 07-variable-or-doublequote
+07-variable-or-empty
 
 08-variable-and
 08-variable-not-and

gash/environment.scm

@@ -41,7 +41,8 @@
 ;; FIXME: export/env vs set
 (define %global-variables
   (map identity ;; FIXME: make mutable
-       `(,(cons "SHELLOPTS" "")
+       `(,(cons "SHELL" (car (command-line)))
+         ,(cons "SHELLOPTS" "")
          ,(cons "PIPESTATUS" "([0]=\"0\"")
          ,(cons "?" "0")
          ,@(map (lambda (key-value)

gash/grammar.scm

@@ -139,7 +139,7 @@
      variable-subst   <-  dollar lbrace (variable-or / variable-and / variable-regex) rbrace
      variable-or      <-- name min variable-word variable-word*
      variable-and     <-- name plus variable-word variable-word*
-     variable-word    <-  variable-regex / substitution / variable-subst / variable / variable-literal !slash / variable-string
+     variable-word    <-  variable-regex / substitution / variable-subst / variable / variable-literal !slash / variable-string / sp*
      variable-regex   <-- name &slash regex-sep variable-literal '/' variable-string &rbrace /
                           name regex-sep variable-string
      slash            <   '/'

test/07-variable-or-empty.sh

@@ -0,0 +1 @@
+echo ${bindir-}

test/07-variable-or-empty.stdout

@@ -0,0 +1 @@
+