Rearrange rpmdbInitIterator() a bit for clarity

- Avoid allocating the iterator until we know it's not an error.
  Doing the chaining earlier doesn't help anything here as the
  cursor used here wasn't linked to the mi at this point, and avoids
  having to free up partially initialized structure in case of errors.
- Group the mi initialization to make the actual initialization
  stand out from the (unnecessary) zeroing of the calloc()'ed struct.

diff --git a/lib/rpmdb.c b/lib/rpmdb.c
index 41ee92c..211a289 100644 (file)
--- a/lib/rpmdb.c
+++ b/lib/rpmdb.c
@@ -1949,7 +1949,7 @@ int rpmdbAppendIterator(rpmdbMatchIterator mi, const int * hdrNums, int nHdrNums
 rpmdbMatchIterator rpmdbInitIterator(rpmdb db, rpmTag rpmtag,
                const void * keyp, size_t keylen)
 {
-    rpmdbMatchIterator mi;
+    rpmdbMatchIterator mi = NULL;
     dbiIndexSet set = NULL;
     dbiIndex dbi;
     void * mi_keyp = NULL;
@@ -1970,11 +1970,6 @@ rpmdbMatchIterator rpmdbInitIterator(rpmdb db, rpmTag rpmtag,
     if (dbi == NULL)
        return NULL;
 
-    /* Chain cursors for teardown on abnormal exit. */
-    mi = xcalloc(1, sizeof(*mi));
-    mi->mi_next = rpmmiRock;
-    rpmmiRock = mi;
-
     /*
      * Handle label and file name special cases.
      * Otherwise, retrieve join keys for secondary lookup.
@@ -2022,10 +2017,7 @@ rpmdbMatchIterator rpmdbInitIterator(rpmdb db, rpmTag rpmtag,
        }
        if (rc) {       /* error/not found */
            set = dbiFreeIndexSet(set);
-           rpmmiRock = mi->mi_next;
-           mi->mi_next = NULL;
-           mi = _free(mi);
-           return NULL;
+           goto exit;
        }
     }
 
@@ -2054,14 +2046,18 @@ rpmdbMatchIterator rpmdbInitIterator(rpmdb db, rpmTag rpmtag,
        }
     }
 
+    mi = xcalloc(1, sizeof(*mi));
     mi->mi_keyp = mi_keyp;
     mi->mi_keylen = keylen;
-
+    mi->mi_set = set;
     mi->mi_db = rpmdbLink(db);
     mi->mi_rpmtag = rpmtag;
 
+    /* Chain cursors for teardown on abnormal exit. */
+    mi->mi_next = rpmmiRock;
+    rpmmiRock = mi;
+
     mi->mi_dbc = NULL;
-    mi->mi_set = set;
     mi->mi_setx = 0;
     mi->mi_h = NULL;
     mi->mi_sorted = 0;
@@ -2076,6 +2072,7 @@ rpmdbMatchIterator rpmdbInitIterator(rpmdb db, rpmTag rpmtag,
     mi->mi_ts = NULL;
     mi->mi_hdrchk = NULL;
 
+exit:
     return mi;
 }