Improper array name validation for the 'mapfile' builtin

[Eduardo A . Bustamante López]

Hi Chet,

It seems like the variable name validation for the mapfile builtin is a bit
wrong. I hope the patch below fixes it.

Demonstration:

| dualbus@hp ...local/src/bash % : before patch
| dualbus@hp ...local/src/bash % /bin/bash -c 'mapfile -t "a[\$(ls)]" <<< ""; 
declare -p'|grep -F '[$('
| declare -a a[$(ls)]='([0]="")'
| 
| dualbus@hp ...local/src/bash % : after patch
| dualbus@hp ...local/src/bash % ./bash -c 'mapfile -t "a[\$(ls)]" <<< ""; 
declare -p'|grep -F '[$('
| ./bash: line 0: mapfile: `a[$(ls)]': not a valid identifier


Patch:

diff --git a/builtins/mapfile.def b/builtins/mapfile.def
index 5e258bb..51e37c6 100644
--- a/builtins/mapfile.def
+++ b/builtins/mapfile.def
@@ -349,7 +349,7 @@ mapfile_builtin (list)
   else
     array_name = list->word->word;
   
-  if (legal_identifier (array_name) == 0 && valid_array_reference (array_name) 
== 0)
+  if (legal_identifier (array_name) == 0)
     {
       sh_invalidid (array_name);
       return (EXECUTION_FAILURE);