1 files changed, 4 insertions, 1 deletions
diff --git a/src/init.cpp b/src/init.cpp
index 8fec69c2b8..2ea778a5b1 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1452,7 +1452,10 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
                     assert(chainActive.Tip() != NULL);
                 }
 
-                if (!fReindex && chainActive.Tip() != NULL) {
+                if (!fReindex) {
+                    // Note that RewindBlockIndex MUST run even if we're about to -reindex-chainstate.
+                    // It both disconnects blocks based on chainActive, and drops block data in
+                    // mapBlockIndex based on lack of available witness data.
                     uiInterface.InitMessage(_("Rewinding blocks..."));
                     if (!RewindBlockIndex(chainparams)) {
                         strLoadError = _("Unable to rewind the database to a pre-fork state. You will need to redownload the blockchain");