From e703ba7bc19f95b6b8d3fb02e7724b88f6233ef6 Mon Sep 17 00:00:00 2001
From: "waterson%netscape.com" <waterson%netscape.com>
Date: Fri, 31 Mar 2000 03:52:55 +0000
Subject: [PATCH] Fix off-by-one error that could occur if you try to inspect
 an RDF container during renumbering.

---
 rdf/base/src/nsRDFContainer.cpp | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/rdf/base/src/nsRDFContainer.cpp b/rdf/base/src/nsRDFContainer.cpp
index ff38cdf11246..ccc234a4f08e 100644
--- a/rdf/base/src/nsRDFContainer.cpp
+++ b/rdf/base/src/nsRDFContainer.cpp
@@ -549,6 +549,14 @@ RDFContainerImpl::Renumber(PRInt32 aStartIndex, PRInt32 aIncrement)
     rv = GetCount(&count);
     if (NS_FAILED(rv)) return rv;
 
+    if (aIncrement > 0) {
+        // Update the container's nextVal to reflect the
+        // renumbering. We do this now if aIncrement > 0 because we'll
+        // want to be able to acknowledge that new elements are in the
+        // container.
+        rv = SetNextValue(count + aIncrement + 1);
+        if (NS_FAILED(rv)) return rv;
+    }
 
     PRInt32 i;
     if (aIncrement < 0) {
@@ -604,9 +612,14 @@ RDFContainerImpl::Renumber(PRInt32 aStartIndex, PRInt32 aIncrement)
         i -= aIncrement;
     }
 
-    // Update the container's nextVal to reflect the renumbering
-    rv = SetNextValue(count + aIncrement + 1);
-    if (NS_FAILED(rv)) return rv;
+    if (aIncrement < 0) {
+        // Update the container's nextVal to reflect the
+        // renumbering. We do this now if aIncrement < 0 because, up
+        // until this point, we'll want people to be able to find
+        // things that are still "at the end".
+        rv = SetNextValue(count + aIncrement + 1);
+        if (NS_FAILED(rv)) return rv;
+    }
 
     return NS_OK;
 }