Updated fix of array_rshift() in array.c

[William Park]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/local/share/locale' -DPACKAGE='bash' 
-DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib   -O4
uname output: Linux node1 2.6.11-smp #2 SMP Thu Mar 3 09:53:04 EST 2005 i686 
unknown unknown GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.0
Patch Level: 0
Release Status: release

Description:
        It's not visible to user.  But, I remember submitting a fix for
        this problem.  Here is an updated patch.

        In array_rshift() in array.c, 'max_index' is incremented, even
        if array is empty.  So, if shift is greater than 1 (say, 5),
        then 'max_index' will end up being fictitious.  You won't be
        able to insert any item from 1 to 5.  You have to insert at
        index greater than 5 in order to force 'max_index' to be real
        again.  Then, you can insert as normal.

Fix:

--- ../bash-3.0/array.c 2004-05-06 08:24:13.000000000 -0400
+++ array.c     2005-05-31 16:21:24.000000000 -0400
@@ -255,7 +255,9 @@
                a->num_elements++;
        }
 
+#if 0          /* Move to the end.  --William */
        a->max_index += n;
+#endif
 
        /*
         * Renumber all elements in the array except the one we just added.
@@ -263,6 +265,14 @@
        for ( ; ae != a->head; ae = element_forw(ae))
                element_index(ae) += n;
 
+       /* Fix:  If array is empty and you shift 5, then 'max_index' increases
+        * from -1 to 4.  But, you still have empty array (if S is NULL) or have
+        * only element (ie. array[0]=S).  Later on, array_insert() cannot find
+        * place to insert for array[1] to array[4].  Adjust 'max_index' after
+        * all other indexes have been incremented.  --William
+        */
+       a->max_index = element_index (a->head->prev);
+
        return (a->num_elements);
 }
 
@@ -451,7 +461,10 @@
                         */
                        array_dispose_element(new);
                        free(element_value(ae));
-                       ae->value = savestring(v);
+
+                       /* Fix: savestring() cannot take NULL argument  
--William */
+                       ae->value = v ? savestring(v) : (char *)NULL;
+
                        return(0);
                } else if (element_index(ae) > i) {
                        ADD_BEFORE(ae, new);