updated for version 7.4.191

Problem:    Escaping a file name for shell commands can't be done without a
            function.
Solution:   Add the :S file name modifier.

src/eval.c

@@ -16950,7 +16950,7 @@ f_shellescape(argvars, rettv)
     typval_T	*rettv;
 {
     rettv->vval.v_string = vim_strsave_shellescape(
-		       get_tv_string(&argvars[0]), non_zero_arg(&argvars[1]));
+		get_tv_string(&argvars[0]), non_zero_arg(&argvars[1]), TRUE);
     rettv->v_type = VAR_STRING;
 }
 
@@ -24355,6 +24355,17 @@ repeat:
 	}
     }
 
+    if (src[*usedlen] == ':' && src[*usedlen + 1] == 'S')
+    {
+	p = vim_strsave_shellescape(*fnamep, FALSE, FALSE);
+	if (p == NULL)
+	    return -1;
+	vim_free(*bufp);
+	*bufp = *fnamep = p;
+	*fnamelen = (int)STRLEN(p);
+	*usedlen += 2;
+    }
+
     return valid;
 }