diff --git a/xwords4/common/dbgutil.c b/xwords4/common/dbgutil.c
index fefb804c1..d6bbec783 100644
--- a/xwords4/common/dbgutil.c
+++ b/xwords4/common/dbgutil.c
@@ -94,9 +94,9 @@ dbg_logstream( const XWStreamCtxt* stream, const char* func, int line )
     if ( !!stream ) {
         XP_U16 len = 0;
         XWStreamPos end = stream_getPos( stream, POS_WRITE );
-        stream_copyBits( stream, 0, end, NULL, &len );
+        stream_copyBits( stream, end, NULL, &len );
         XP_U8 buf[len];
-        stream_copyBits( stream, 0, end, buf, &len );
+        stream_copyBits( stream, end, buf, &len );
         char comment[128];
         XP_SNPRINTF( comment, VSIZE(comment), "%s line %d", func, line );
         LOG_HEX( buf, len, comment );
diff --git a/xwords4/common/memstream.c b/xwords4/common/memstream.c
index 1650aa34c..4759c6ffe 100644
--- a/xwords4/common/memstream.c
+++ b/xwords4/common/memstream.c
@@ -186,8 +186,8 @@ mem_stream_getBits( XWStreamCtxt* p_sctx, XP_U16 nBits )
 
 #if defined HASH_STREAM || defined DEBUG
 static void
-mem_stream_copyBits( const XWStreamCtxt* p_sctx, XWStreamPos XP_UNUSED(startPos),
-                     XWStreamPos endPos, XP_U8* buf, XP_U16* lenp )
+mem_stream_copyBits( const XWStreamCtxt* p_sctx, XWStreamPos endPos,
+                     XP_U8* buf, XP_U16* lenp )
 {
     MemStreamCtxt* stream = (MemStreamCtxt*)p_sctx;
     XP_U16 len = BYTE_PART(endPos);
diff --git a/xwords4/common/model.c b/xwords4/common/model.c
index ef5c17c4b..89d0d5981 100644
--- a/xwords4/common/model.c
+++ b/xwords4/common/model.c
@@ -343,7 +343,7 @@ model_hashMatches( const ModelCtxt* model, const XP_U32 hash )
 }
 
 XP_Bool
-model_revertToHash( ModelCtxt* model, const XP_U32 hash, PoolContext* pool )
+model_popToHash( ModelCtxt* model, const XP_U32 hash, PoolContext* pool )
 {
     XP_U16 nPopped = 0;
     StackCtxt* stack = model->vol.stack;
diff --git a/xwords4/common/model.h b/xwords4/common/model.h
index f9e688494..85ae51fa4 100644
--- a/xwords4/common/model.h
+++ b/xwords4/common/model.h
@@ -124,8 +124,8 @@ void model_setSize( ModelCtxt* model, XP_U16 boardSize );
 void model_destroy( ModelCtxt* model );
 XP_U32 model_getHash( const ModelCtxt* model, XP_U16 version );
 XP_Bool model_hashMatches( const ModelCtxt* model, XP_U32 hash );
-XP_Bool model_revertToHash( ModelCtxt* model, const XP_U32 hash,
-                            PoolContext* pool );
+XP_Bool model_popToHash( ModelCtxt* model, const XP_U32 hash,
+                         PoolContext* pool );
 
 void model_setNPlayers( ModelCtxt* model, XP_U16 numPlayers );
 XP_U16 model_getNPlayers( const ModelCtxt* model );
diff --git a/xwords4/common/movestak.c b/xwords4/common/movestak.c
index b3b40619a..661236b8c 100644
--- a/xwords4/common/movestak.c
+++ b/xwords4/common/movestak.c
@@ -150,10 +150,10 @@ stack_getHash( const StackCtxt* stack )
     XP_U32 hash = 0;
     if ( !!stack->data ) {
         XP_U16 len = 0;
-        stream_copyBits( stack->data, 0, stack->top, NULL, &len );
+        stream_copyBits( stack->data, stack->top, NULL, &len );
         if ( 0 < len ) {
             XP_U8 buf[len];
-            stream_copyBits( stack->data, 0, stack->top, buf, &len );
+            stream_copyBits( stack->data, stack->top, buf, &len );
 #ifdef DEBUG_HASHING
             LOG_HEX( buf, len, __func__ );
 #endif
diff --git a/xwords4/common/server.c b/xwords4/common/server.c
index e9f6bea8d..9da915301 100644
--- a/xwords4/common/server.c
+++ b/xwords4/common/server.c
@@ -2087,8 +2087,7 @@ readMoveInfo( ServerCtxt* server, XWStreamCtxt* stream,
     if ( STREAM_VERS_BIGBOARD <= stream_getVersion( stream ) ) {
         XP_U32 hashReceived = stream_getU32( stream );
         success = model_hashMatches( server->vol.model, hashReceived )
-            || model_revertToHash( server->vol.model, hashReceived,
-                                   server->pool );
+            || model_popToHash( server->vol.model, hashReceived, server->pool );
         // XP_ASSERT( success );   /* I need to understand when this can fail */
 #ifdef DEBUG_HASHING
         if ( success ) {
diff --git a/xwords4/common/xwstream.h b/xwords4/common/xwstream.h
index dc5dfd060..cc6305d3a 100644
--- a/xwords4/common/xwstream.h
+++ b/xwords4/common/xwstream.h
@@ -49,8 +49,8 @@ typedef struct StreamCtxVTable {
     XP_U32 (*m_stream_getU32)( XWStreamCtxt* dctx );
     XP_U32 (*m_stream_getBits)( XWStreamCtxt* dctx, XP_U16 nBits );
 #if defined HASH_STREAM || defined DEBUG
-    void (*m_stream_copyBits)( const XWStreamCtxt* dctx, XWStreamPos startPos,
-                               XWStreamPos endPos, XP_U8* buf, XP_U16* len );
+    void (*m_stream_copyBits)( const XWStreamCtxt* dctx, XWStreamPos endPos,
+                               XP_U8* buf, XP_U16* len );
 #endif
 
     void (*m_stream_putU8)( XWStreamCtxt* dctx, XP_U8 byt );
@@ -114,8 +114,8 @@ struct XWStreamCtxt {
          (sc)->vtable->m_stream_getBits((sc), (n))
 
 #if defined HASH_STREAM || defined DEBUG
-#define stream_copyBits(sc, s, e, b, l) \
-         (sc)->vtable->m_stream_copyBits((sc), (s), (e), (b), (l))
+#define stream_copyBits(sc, e, b, l) \
+         (sc)->vtable->m_stream_copyBits((sc), (e), (b), (l))
 #endif
 
 #define stream_putU8(sc, b) \