Change hdrNumCmp to use the tagNum as secondary sort key

This brings rpmdbSortIterator in line with its documentation.

Note that there is a catch: this change also makes the dbiIndexSetPrune
function work different! It used to delete all items that had a
matching hdrNum, after the change only the one is deleted that also
has a matching tagNum. I consider this a bug fix.
Note that dbiIndexSetPrune is only used in the db3.c backend to remove
index entires, if we really want the old behavior we should add a
new dbiIndexSetPruneHdrnum function.

Also remove assertion when trying to sort an empty set.

(cherry picked from commit eb6b13f9a75ba744c88f5a74f183a210554a5c0c)

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/backend/dbiset.c b/lib/backend/dbiset.c
index 0ac514582..8fb922ef7 100644
--- a/lib/backend/dbiset.c
+++ b/lib/backend/dbiset.c
@@ -31,11 +31,12 @@ void dbiIndexSetGrow(dbiIndexSet set, unsigned int nrecs)
     }
 }
 
-/* XXX assumes hdrNum is first int in dbiIndexItem */
 static int hdrNumCmp(const void * one, const void * two)
 {
-    const unsigned int * a = one, * b = two;
-    return (*a - *b);
+    const struct dbiIndexItem_s *a = one, *b = two;
+    if (a->hdrNum - b->hdrNum != 0)
+	return a->hdrNum - b->hdrNum;
+    return a->tagNum - b->tagNum;
 }
 
 void dbiIndexSetSort(dbiIndexSet set)
@@ -59,7 +60,8 @@ void dbiIndexSetUniq(dbiIndexSet set, int sorted)
     unsigned int to = 0;
     unsigned int num = set->count;
 
-    assert(set->count > 0);
+    if (set->count < 2)
+	return;
 
     if (!sorted)
 	dbiIndexSetSort(set);