https://github.com/zcash/zcash/pull/3670/files

src/gtest/test_checkblock.cpp

@@ -291,7 +291,7 @@ TEST_F(ContextualCheckBlockTest, BlockOverwinterRulesRejectOtherTx) {
 
     {
         SCOPED_TRACE("BlockOverwinterRulesRejectSaplingTx");
-        ExpectInvalidBlockFromTx(CTransaction(mtx), 100, "bad-overwinter-tx-version-group-id");
+        ExpectInvalidBlockFromTx(CTransaction(mtx), 0, "bad-overwinter-tx-version-group-id");
     }
 }
 
@@ -319,6 +319,6 @@ TEST_F(ContextualCheckBlockTest, BlockSaplingRulesRejectOtherTx) {
 
     {
         SCOPED_TRACE("BlockSaplingRulesRejectOverwinterTx");
-        ExpectInvalidBlockFromTx(CTransaction(mtx), 100, "bad-sapling-tx-version-group-id");
+        ExpectInvalidBlockFromTx(CTransaction(mtx), 0, "bad-sapling-tx-version-group-id");
     }
 }

src/main.cpp

@@ -1034,9 +1034,12 @@ bool ContextualCheckTransaction(
         }
 
         // Reject transactions with non-Sapling version group ID
-        if (tx.fOverwintered && tx.nVersionGroupId != SAPLING_VERSION_GROUP_ID) {
-            return state.DoS(dosLevel, error("CheckTransaction(): invalid Sapling tx version"),
-                    REJECT_INVALID, "bad-sapling-tx-version-group-id");
+        if (tx.fOverwintered && tx.nVersionGroupId != SAPLING_VERSION_GROUP_ID)
+        {
+            //return state.DoS(dosLevel, error("CheckTransaction(): invalid Sapling tx version"),REJECT_INVALID, "bad-sapling-tx-version-group-id");
+            return state.DoS(isInitBlockDownload() ? 0 : dosLevel,
+                             error("CheckTransaction(): invalid Sapling tx version"),
+                             REJECT_INVALID, "bad-sapling-tx-version-group-id");
         }
 
         // Reject transactions with invalid version
@@ -1058,9 +1061,12 @@ bool ContextualCheckTransaction(
         }
 
         // Reject transactions with non-Overwinter version group ID
-        if (tx.fOverwintered && tx.nVersionGroupId != OVERWINTER_VERSION_GROUP_ID) {
-            return state.DoS(dosLevel, error("CheckTransaction(): invalid Overwinter tx version"),
-                    REJECT_INVALID, "bad-overwinter-tx-version-group-id");
+        if (tx.fOverwintered && tx.nVersionGroupId != OVERWINTER_VERSION_GROUP_ID)
+        {
+            //return state.DoS(dosLevel, error("CheckTransaction(): invalid Overwinter tx version"),REJECT_INVALID, "bad-overwinter-tx-version-group-id");
+            return state.DoS(isInitBlockDownload() ? 0 : dosLevel,
+                             error("CheckTransaction(): invalid Overwinter tx version"),
+                             REJECT_INVALID, "bad-overwinter-tx-version-group-id");
         }
 
         // Reject transactions with invalid version