Bug: backend crashes in btbeginscan()->btrescan()->_bt_orderkeys()

vadim4o · vadim4o · commit c3b51e0d676c · 1997-05-05T03:41:19.000Z
when btree used in innerscan with run-time key which value
passed by pointer.

Fix: keys ordering stuff moved to _bt_first().

Pointed by Thomas Lockhart.
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.18 1997/04/18 03:37:53 vadim Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.19 1997/05/05 03:41:17 vadim Exp $
  *
  * NOTES
  *    This file contains only the public interface routines.
@@ -410,7 +410,6 @@ btrescan(IndexScanDesc scan, bool fromEnd, ScanKey scankey)
 {
     ItemPointer iptr;
     BTScanOpaque so;
-    StrategyNumber strat;
     
     so = (BTScanOpaque) scan->opaque;
     
@@ -439,32 +438,18 @@ btrescan(IndexScanDesc scan, bool fromEnd, ScanKey scankey)
 	scan->flags = 0x0;
     }
     
-    /* reset the scan key */
+    /* 
+     * Reset the scan keys. Note that keys ordering stuff
+     * moved to _bt_first.	- vadim 05/05/97
+     */
     so->numberOfKeys = scan->numberOfKeys;
-    so->numberOfFirstKeys = 0;		/* may be changed by _bt_orderkeys */
-    so->qual_ok = 1;			/* may be changed by _bt_orderkeys */
     if (scan->numberOfKeys > 0) {
 	memmove(scan->keyData,
 		scankey,
 		scan->numberOfKeys * sizeof(ScanKeyData));
 	memmove(so->keyData,
 		scankey,
 		so->numberOfKeys * sizeof(ScanKeyData));
-	/* order the keys in the qualification */
-	_bt_orderkeys(scan->relation, so);
-    }
-    
-    /* finally, be sure that the scan exploits the tree order */
-    scan->scanFromEnd = false;
-    if ( so->numberOfKeys > 0 ) {
-	strat = _bt_getstrat(scan->relation, 1 /* XXX */,
-			     so->keyData[0].sk_procedure);
-	
-	if (strat == BTLessStrategyNumber
-	    || strat == BTLessEqualStrategyNumber)
-	    scan->scanFromEnd = true;
-    } else {
-	scan->scanFromEnd = true;
     }
 
 }
diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.18 1997/04/24 15:46:44 vadim Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.19 1997/05/05 03:41:19 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -751,16 +751,38 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
     ScanKeyData skdata;
     Size keysok;
     
+    rel = scan->relation;
     so = (BTScanOpaque) scan->opaque;
-    if ( so->qual_ok == 0 )		/* may be set by _bt_orderkeys */
+    
+    /* 
+     * Order the keys in the qualification and be sure
+     * that the scan exploits the tree order.
+     */
+    so->numberOfFirstKeys = 0;		/* may be changed by _bt_orderkeys */
+    so->qual_ok = 1;			/* may be changed by _bt_orderkeys */
+    scan->scanFromEnd = false;
+    if ( so->numberOfKeys > 0 )
+    {
+    	_bt_orderkeys(rel, so);
+    	
+	strat = _bt_getstrat(rel, 1, so->keyData[0].sk_procedure);
+
+	/* NOTE: it assumes ForwardScanDirection */
+	if ( strat == BTLessStrategyNumber || 
+		strat == BTLessEqualStrategyNumber )
+	    scan->scanFromEnd = true;
+    }
+    else
+    	scan->scanFromEnd = true;
+
+    if ( so->qual_ok == 0 )
     	return ((RetrieveIndexResult) NULL);
     
     /* if we just need to walk down one edge of the tree, do that */
     if (scan->scanFromEnd)
 	return (_bt_endpoint(scan, dir));
     
-    rel = scan->relation;
-    itupdesc = RelationGetTupleDescriptor(scan->relation);
+    itupdesc = RelationGetTupleDescriptor(rel);
     current = &(scan->currentItemData);
     
     /*
