Fix bug reported by bobson: aclinsert3 would delete the 'world' entry

from an ACL list if it had no permissions remaining, which confused
aclcheck terribly.  Also clean up code a little.

diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 2fb21afd819439dd3ce4bcdbfa270d78de01863e..1a2b2ef953e7bda0ae01ccdd9a1ef2a887dea805 100644 (file)
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/adt/acl.c,v 1.51 2000/10/16 17:08:08 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/adt/acl.c,v 1.52 2000/11/03 19:01:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -212,8 +212,7 @@ makeacl(int n)
    if (n < 0)
        elog(ERROR, "makeacl: invalid size: %d", n);
    size = ACL_N_SIZE(n);
-   if (!(new_acl = (Acl *) palloc(size)))
-       elog(ERROR, "makeacl: palloc failed on %d", size);
+   new_acl = (Acl *) palloc(size);
    MemSet((char *) new_acl, 0, size);
    new_acl->size = size;
    new_acl->ndim = 1;
@@ -382,7 +381,7 @@ aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
 
    /* These checks for null input are probably dead code, but... */
    if (!old_acl || ACL_NUM(old_acl) < 1)
-       old_acl = makeacl(0);
+       old_acl = makeacl(1);
    if (!mod_aip)
    {
        new_acl = makeacl(ACL_NUM(old_acl));
@@ -402,12 +401,13 @@ aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
    /* find the first element not less than the element to be inserted */
    for (dst = 0; dst < num && aclitemgt(mod_aip, old_aip + dst); ++dst)
        ;
+
    if (dst < num && aclitemeq(mod_aip, old_aip + dst))
    {
        /* modify in-place */
-       new_acl = makeacl(ACL_NUM(old_acl));
-       memcpy((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
+       new_acl = makeacl(num);
        new_aip = ACL_DAT(new_acl);
+       memcpy((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
        src = dst;
    }
    else
@@ -420,24 +420,26 @@ aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
        }
        else if (dst >= num)
        {                       /* end */
-           memmove((char *) new_aip,
-                   (char *) old_aip,
-                   num * sizeof(AclItem));
+           memcpy((char *) new_aip,
+                  (char *) old_aip,
+                  num * sizeof(AclItem));
        }
        else
        {                       /* middle */
-           memmove((char *) new_aip,
-                   (char *) old_aip,
-                   dst * sizeof(AclItem));
-           memmove((char *) (new_aip + dst + 1),
-                   (char *) (old_aip + dst),
-                   (num - dst) * sizeof(AclItem));
+           memcpy((char *) new_aip,
+                  (char *) old_aip,
+                  dst * sizeof(AclItem));
+           memcpy((char *) (new_aip + dst + 1),
+                  (char *) (old_aip + dst),
+                  (num - dst) * sizeof(AclItem));
        }
        new_aip[dst].ai_id = mod_aip->ai_id;
        new_aip[dst].ai_idtype = mod_aip->ai_idtype;
        num++;                  /* set num to the size of new_acl */
-       src = 0;                /* world entry */
+       src = 0;                /* if add or del, start from world entry */
    }
+
+   /* apply the permissions mod */
    switch (modechg)
    {
        case ACL_MODECHG_ADD:
@@ -452,11 +454,11 @@ aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
    }
 
    /*
-    * if the newly added entry has no permissions, delete it from the
+    * if the adjusted entry has no permissions, delete it from the
     * list.  For example, this helps in removing entries for users who no
-    * longer exist...
+    * longer exist.  EXCEPTION: never remove the world entry.
     */
-   if (new_aip[dst].ai_mode == 0)
+   if (new_aip[dst].ai_mode == 0 && dst > 0)
    {
        int         i;
 
@@ -467,7 +469,7 @@ aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
            new_aip[i - 1].ai_mode = new_aip[i].ai_mode;
        }
        ARR_DIMS(new_acl)[0] = num - 1;
-       /* Adjust also the array size because it is used for memmove */
+       /* Adjust also the array size because it is used for memcpy */
        ARR_SIZE(new_acl) -= sizeof(AclItem);
    }
 
@@ -500,7 +502,7 @@ aclremove(PG_FUNCTION_ARGS)
 
    /* These checks for null input should be dead code, but... */
    if (!old_acl || ACL_NUM(old_acl) < 1)
-       old_acl = makeacl(0);
+       old_acl = makeacl(1);
    if (!mod_aip)
    {
        new_acl = makeacl(ACL_NUM(old_acl));
@@ -511,11 +513,14 @@ aclremove(PG_FUNCTION_ARGS)
    old_num = ACL_NUM(old_acl);
    old_aip = ACL_DAT(old_acl);
 
+   /* Search for the matching entry */
    for (dst = 0; dst < old_num && !aclitemeq(mod_aip, old_aip + dst); ++dst)
        ;
+
    if (dst >= old_num)
-   {                           /* not found or empty */
-       new_acl = makeacl(ACL_NUM(old_acl));
+   {
+       /* Not found, so return copy of source ACL */
+       new_acl = makeacl(old_num);
        memcpy((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
    }
    else
@@ -529,20 +534,21 @@ aclremove(PG_FUNCTION_ARGS)
        }
        else if (dst == old_num - 1)
        {                       /* end */
-           memmove((char *) new_aip,
-                   (char *) old_aip,
-                   new_num * sizeof(AclItem));
+           memcpy((char *) new_aip,
+                  (char *) old_aip,
+                  new_num * sizeof(AclItem));
        }
        else
        {                       /* middle */
-           memmove((char *) new_aip,
-                   (char *) old_aip,
-                   dst * sizeof(AclItem));
-           memmove((char *) (new_aip + dst),
-                   (char *) (old_aip + dst + 1),
-                   (new_num - dst) * sizeof(AclItem));
+           memcpy((char *) new_aip,
+                  (char *) old_aip,
+                  dst * sizeof(AclItem));
+           memcpy((char *) (new_aip + dst),
+                  (char *) (old_aip + dst + 1),
+                  (new_num - dst) * sizeof(AclItem));
        }
    }
+
    PG_RETURN_ACL_P(new_acl);
 }