[autoprune] allow wallet in pruned mode

Author: jonasschnelli

src/init.cpp

@@ -714,16 +714,12 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         nMaxConnections = nFD - MIN_CORE_FILEDESCRIPTORS;
 
     // if using block pruning, then disable txindex
-    // also disable the wallet (for now, until SPV support is implemented in wallet)
     if (GetArg("-prune", 0)) {
         if (GetBoolArg("-txindex", false))
             return InitError(_("Prune mode is incompatible with -txindex."));
 #ifdef ENABLE_WALLET
-        if (!GetBoolArg("-disablewallet", false)) {
-            if (SoftSetBoolArg("-disablewallet", true))
-                LogPrintf("%s : parameter interaction: -prune -> setting -disablewallet=1\n", __func__);
-            else
-                return InitError(_("Can't run with a wallet in prune mode."));
+        if (GetBoolArg("-rescan", false)) {
+            return InitError(_("Rescans are not possible in pruned mode. You will need to use -reindex which will download the whole blockchain again."));
         }
 #endif
     }
@@ -1316,6 +1312,19 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         }
         if (chainActive.Tip() && chainActive.Tip() != pindexRescan)
         {
+            //We can't rescan beyond non-pruned blocks, stop and throw an error
+            //this might happen if a user uses a old wallet within a pruned node
+            // or if he ran -disablewallet for a longer time, then decided to re-enable
+            if (fPruneMode)
+            {
+                CBlockIndex *block = chainActive.Tip();
+                while (block && block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA) && pindexRescan != block)
+                    block = block->pprev;
+
+                if (pindexRescan != block)
+                    return InitError(_("Prune: last wallet synchronisation goes beyond pruned data. You need to -reindex (download the whole blockchain again in case of pruned node)"));
+            }
+
             uiInterface.InitMessage(_("Rescanning..."));
             LogPrintf("Rescanning last %i blocks (from block %i)...\n", chainActive.Height() - pindexRescan->nHeight, pindexRescan->nHeight);
             nStart = GetTimeMillis();