Fix aclexplode to not explode on a zero-entry ACL array.

(An Assert is no substitute for thinking clearly :-()

Minor style kibitzing too.

Per report from Robert Treat.

diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index f705d0eac10db5d521b51920ae12c06f6e88efe6..52e49999003c707d24a34ebe612fb2d3b445ec13 100644 (file)
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/utils/adt/acl.c,v 1.154 2010/01/02 16:57:53 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/utils/adt/acl.c,v 1.155 2010/01/12 02:39:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1680,9 +1680,9 @@ convert_aclright_to_string(int aclright)
 Datum
 aclexplode(PG_FUNCTION_ARGS)
 {
+   Acl        *acl = PG_GETARG_ACL_P(0);
    FuncCallContext *funcctx;
    int        *idx;
-   Acl        *acl = PG_GETARG_ACL_P(0);
    AclItem    *aidat;
 
    if (SRF_IS_FIRSTCALL())
@@ -1722,34 +1722,36 @@ aclexplode(PG_FUNCTION_ARGS)
 
    funcctx = SRF_PERCALL_SETUP();
    idx = (int *) funcctx->user_fctx;
-
    aidat = ACL_DAT(acl);
-   while (1)
+
+   /* need test here in case acl has no items */
+   while (idx[0] < ACL_NUM(acl))
    {
+       AclItem    *aidata;
+       AclMode     priv_bit;
+
        idx[1]++;
        if (idx[1] == N_ACL_RIGHTS)
        {
            idx[1] = 0;
            idx[0]++;
-           if (idx[0] == ACL_NUM(acl))
-               /* done */
+           if (idx[0] >= ACL_NUM(acl))             /* done */
                break;
        }
+       aidata = &aidat[idx[0]];
+       priv_bit = 1 << idx[1];
 
-       Assert(idx[0] < ACL_NUM(acl));
-       Assert(idx[1] < N_ACL_RIGHTS);
-
-       if (ACLITEM_GET_PRIVS(aidat[idx[0]]) & (1 << idx[1]))
+       if (ACLITEM_GET_PRIVS(*aidata) & priv_bit)
        {
            Datum       result;
            Datum       values[4];
            bool        nulls[4];
            HeapTuple   tuple;
 
-           values[0] = ObjectIdGetDatum(aidat[idx[0]].ai_grantor);
-           values[1] = ObjectIdGetDatum(aidat[idx[0]].ai_grantee);
-           values[2] = CStringGetTextDatum(convert_aclright_to_string(1 << idx[1]));
-           values[3] = BoolGetDatum(ACLITEM_GET_GOPTIONS(aidat[idx[0]]) & (1 << idx[1]));
+           values[0] = ObjectIdGetDatum(aidata->ai_grantor);
+           values[1] = ObjectIdGetDatum(aidata->ai_grantee);
+           values[2] = CStringGetTextDatum(convert_aclright_to_string(priv_bit));
+           values[3] = BoolGetDatum((ACLITEM_GET_GOPTIONS(*aidata) & priv_bit) != 0);
 
            MemSet(nulls, 0, sizeof(nulls));