Fix uninitialized value in pgstatindex leading to invalid values being

reported in some cases.  Report and patch from Tatsuhito Kasahara.

Also fix a couple of other bugs I noticed in skimming the surrounding code.

diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
index d684a3e055ee14fd757e56b3a6ff16837eade640..2982ceaf50645fc26ff77b933779127ced3db8c1 100644 (file)
--- a/contrib/pgstattuple/pgstatindex.c
+++ b/contrib/pgstattuple/pgstatindex.c
@@ -139,7 +139,7 @@ typedef struct BTIndexStat
  * Collect statistics of single b-tree leaf page
  * -------------------------------------------------
  */
-static bool
+static void
 GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
 {
    Page        page = BufferGetPage(buffer);
@@ -154,6 +154,7 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
    stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData);
 
    stat->dead_items = stat->live_items = 0;
+   stat->fragments = 0;
 
    stat->page_size = PageGetPageSize(page);
 
@@ -161,7 +162,8 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
    if (P_ISDELETED(opaque))
    {
        stat->type = 'd';
-       return true;
+       stat->btpo.xact = opaque->btpo.xact;
+       return;
    }
    else if (P_IGNORE(opaque))
        stat->type = 'e';
@@ -175,10 +177,7 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
    /* btpage opaque data */
    stat->btpo_prev = opaque->btpo_prev;
    stat->btpo_next = opaque->btpo_next;
-   if (P_ISDELETED(opaque))
-       stat->btpo.xact = opaque->btpo.xact;
-   else
-       stat->btpo.level = opaque->btpo.level;
+   stat->btpo.level = opaque->btpo.level;
    stat->btpo_flags = opaque->btpo_flags;
    stat->btpo_cycleid = opaque->btpo_cycleid;
 
@@ -187,7 +186,6 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
     * it means a fragmentation.
     *----------------------------------------------
     */
-   stat->fragments = 0;
    if (stat->type == 'l')
    {
        if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno)
@@ -216,8 +214,6 @@ GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
        stat->avg_item_size = item_size / (stat->live_items + stat->dead_items);
    else
        stat->avg_item_size = 0;
-
-   return true;
 }
 
 
@@ -338,8 +334,7 @@ pgstatindex(PG_FUNCTION_ARGS)
        int         j;
        char       *values[PGSTATINDEX_NCOLUMNS];
 
-       HeapTupleData tupleData;
-       HeapTuple   tuple = &tupleData;
+       HeapTuple   tuple;
 
        tupleDesc = RelationNameGetTupleDesc(PGSTATINDEX_TYPE);