reflog_expire(): never update a reference to null_sha1

diff --git a/prio-queue.c b/prio-queue.c
index c9f8c6d2532b23ff07194c99c6f4121a7000bed4..e4365b00d6c3366e6753fc6da3fe1a165ab1222d 100644 (file)
--- a/prio-queue.c
+++ b/prio-queue.c
@@ -1,18 +1,30 @@
 #include "cache.h"
-#include "commit.h"
 #include "prio-queue.h"
 
+static inline int compare(struct prio_queue *queue, int i, int j)
+{
+       int cmp = queue->compare(queue->array[i].data, queue->array[j].data,
+                                queue->cb_data);
+       if (!cmp)
+               cmp = queue->array[i].ctr - queue->array[j].ctr;
+       return cmp;
+}
+
+static inline void swap(struct prio_queue *queue, int i, int j)
+{
+       struct prio_queue_entry tmp = queue->array[i];
+       queue->array[i] = queue->array[j];
+       queue->array[j] = tmp;
+}
+
 void prio_queue_reverse(struct prio_queue *queue)
 {
        int i, j;
 
        if (queue->compare != NULL)
                die("BUG: prio_queue_reverse() on non-LIFO queue");
-       for (i = 0; i <= (j = (queue->nr - 1) - i); i++) {
-               struct commit *swap = queue->array[i];
-               queue->array[i] = queue->array[j];
-               queue->array[j] = swap;
-       }
+       for (i = 0; i <= (j = (queue->nr - 1) - i); i++)
+               swap(queue, i, j);
 }
 
 void clear_prio_queue(struct prio_queue *queue)
@@ -21,44 +33,42 @@ void clear_prio_queue(struct prio_queue *queue)
        queue->nr = 0;
        queue->alloc = 0;
        queue->array = NULL;
+       queue->insertion_ctr = 0;
 }
 
 void prio_queue_put(struct prio_queue *queue, void *thing)
 {
-       prio_queue_compare_fn compare = queue->compare;
        int ix, parent;
 
        /* Append at the end */
        ALLOC_GROW(queue->array, queue->nr + 1, queue->alloc);
-       queue->array[queue->nr++] = thing;
-       if (!compare)
+       queue->array[queue->nr].ctr = queue->insertion_ctr++;
+       queue->array[queue->nr].data = thing;
+       queue->nr++;
+       if (!queue->compare)
                return; /* LIFO */
 
        /* Bubble up the new one */
        for (ix = queue->nr - 1; ix; ix = parent) {
                parent = (ix - 1) / 2;
-               if (compare(queue->array[parent], queue->array[ix],
-                           queue->cb_data) <= 0)
+               if (compare(queue, parent, ix) <= 0)
                        break;
 
-               thing = queue->array[parent];
-               queue->array[parent] = queue->array[ix];
-               queue->array[ix] = thing;
+               swap(queue, parent, ix);
        }
 }
 
 void *prio_queue_get(struct prio_queue *queue)
 {
-       void *result, *swap;
+       void *result;
        int ix, child;
-       prio_queue_compare_fn compare = queue->compare;
 
        if (!queue->nr)
                return NULL;
-       if (!compare)
-               return queue->array[--queue->nr]; /* LIFO */
+       if (!queue->compare)
+               return queue->array[--queue->nr].data; /* LIFO */
 
-       result = queue->array[0];
+       result = queue->array[0].data;
        if (!--queue->nr)
                return result;
 
@@ -67,18 +77,14 @@ void *prio_queue_get(struct prio_queue *queue)
        /* Push down the one at the root */
        for (ix = 0; ix * 2 + 1 < queue->nr; ix = child) {
                child = ix * 2 + 1; /* left */
-               if ((child + 1 < queue->nr) &&
-                   (compare(queue->array[child], queue->array[child + 1],
-                            queue->cb_data) >= 0))
+               if (child + 1 < queue->nr &&
+                   compare(queue, child, child + 1) >= 0)
                        child++; /* use right child */
 
-               if (compare(queue->array[ix], queue->array[child],
-                           queue->cb_data) <= 0)
+               if (compare(queue, ix, child) <= 0)
                        break;
 
-               swap = queue->array[child];
-               queue->array[child] = queue->array[ix];
-               queue->array[ix] = swap;
+               swap(queue, child, ix);
        }
        return result;
 }