PackWriter#prepareBitmapIndex: add clarifying comments
New readers of #prepareBitmapIndex may be confused about the manual
memory management (hidden mutation and nulling out pointers).
Add two clarifying comments to help future readers.
Change-Id: I93cab1919066efda37e96c47667f6991f67e377e
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
index 8653c32..d42d348 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/pack/PackWriter.java
@@ -2371,10 +2371,14 @@ public boolean prepareBitmapIndex(ProgressMonitor pm) throws IOException {
int numCommits = objectsLists[OBJ_COMMIT].size();
List<ObjectToPack> byName = sortByName();
+ // Reset sortedByName before the array that it points to is mutated by
+ // PackBitmapIndexBuilder, to prevent other methods referencing the
+ // mutated array afterwards.
sortedByName = null;
objectsLists = null;
objectsMap = null;
writeBitmaps = new PackBitmapIndexBuilder(byName);
+ // Allow byName to be GC'd if JVM GC runs before the end of the method.
byName = null;
PackWriterBitmapPreparer bitmapPreparer = new PackWriterBitmapPreparer(
