hygiene: fix seven latent defects from the v1.2.0 code audit

Phase 1 of the code-hygiene remediation. Each is a genuine defect, not
style. The two consensus functions are touched only by provably
behavior-preserving dead-code removal and a comment.

- miner: initialize the anti-spin loop counter (was `int i;` -- the loop
  condition read an indeterminate value, UB) and break once the block
  time advances past the median, which is what the comment intended.
- consensus/upgrades: drop a stray printf() on the NetworkUpgradeState
  path; the following assert already documents the invariant.
- txdb: CBlockTreeDB::Snapshot2's outer catch treated ANY exception as
  normal end-of-iteration and built a snapshot from partial data. Fail
  instead, matching the inner catch the author marked consensus-relevant
  ("we need to exit here if so for consensus code!"). iter->Valid()
  already handles genuine end-of-iteration.
- wallet/rpcwallet + init: -sietch-min-zouts used a "--" key that the arg
  parser (which normalizes --foo to -foo) can never match, so the Sietch
  decoy floor was silently stuck at the default. Use the single-dash key
  so the knob works, and document it in -help.
- hush_bitcoind + hush_utils: remove four unreachable duplicate `else if`
  branches from hush_commission()/hush_block_subsidy() (a second
  `height < 23860000` and a second `height < 27220000` in each). Proven
  identical across 49,591 heights. NB: the dead values hint at an intended
  clean halving schedule that was never wired up; the DEPLOYED schedule
  (two double-steps) is preserved exactly. Changing it is a future
  consensus decision, not this cleanup.
- hush_bitcoind: replace the "likely a bug" halving TODO with an accurate
  note -- INTERVAL is only consumed by a debug fprintf, so the > vs >=
  boundary at HALVING1 has no consensus effect.
- git rm two committed macOS build artifacts (cc/customcc.dylib and
  libcc.dylib) and add the missing .dylib .gitignore rules.

Built clean on Linux; an isolated node self-mined genesis->5113 exercising
the miner and consensus-subsidy paths, and getsnapshot returned normally.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -160,8 +160,10 @@ doc/man/Makefile.in
 Makefile.in
 src/libcc.so
 src/libcc.dll
+src/libcc.dylib
 src/cc/customcc.so
 src/cc/customcc.dll
+src/cc/customcc.dylib
 src/HUSH3_7776
 REGTEST_7776
 src/cc/librogue.so

src/consensus/upgrades.cpp

@@ -63,10 +63,6 @@ UpgradeState NetworkUpgradeState(
     const Consensus::Params& params,
     Consensus::UpgradeIndex idx)
 {
-    if (nHeight < 0)
-    {
-        printf("height: %d", nHeight);
-    }
     assert(nHeight >= 0);
     assert(idx >= Consensus::BASE_SPROUT && idx < Consensus::MAX_NETWORK_UPGRADES);
     auto nActivationHeight = params.vUpgrades[idx].nActivationHeight;

src/hush_bitcoind.h

@@ -975,8 +975,9 @@ uint64_t hush_commission(int height)
         INTERVAL = GetArg("-ac_halving1",840000), TRANSITION = 129;
     uint64_t commission = 0;
 
-    //TODO: Likely a bug hiding here or at the next halving :)
+    // NB: INTERVAL is consumed only by the debug fprintf at the end of this function;
-    //if( height >= HALVING1) {
+    // the commission schedule below uses hardcoded height thresholds, not INTERVAL. So
+    // the > vs >= boundary at HALVING1 has no consensus effect. Left as > for stability.
     if( height > HALVING1) {
         // Block time going from 150s to 75s (half) means the interval between halvings
         // must be twice as often, i.e. 840000*2=1680000
@@ -1019,14 +1020,14 @@ uint64_t hush_commission(int height)
             commission = 61035;
         } else if (height < 23860000) {
             commission = 30517;
-        } else if (height < 23860000) {
+        // removed unreachable duplicate `height < 23860000` (=> 15258); the schedule
-            commission = 15258;
+        // intentionally drops straight to 7629 next — this is the deployed behavior.
         } else if (height < 25540000) {
             commission = 7629;
         } else if (height < 27220000) {
             commission = 3814;
-        } else if (height < 27220000) {
+        // removed unreachable duplicate `height < 27220000` (=> 1907); the schedule
-            commission = 1907;
+        // intentionally drops straight to 953 next — this is the deployed behavior.
         } else if (height < 28900000) {
             commission = 953;
         } else if (height < 30580000) {

src/hush_utils.h

@@ -1564,14 +1564,14 @@ uint64_t hush_block_subsidy(int height)
             subsidy = 549316;
         } else if (height < 23860000) {
             subsidy = 274658;
-        } else if (height < 23860000) {
+        // removed unreachable duplicate `height < 23860000` (=> 137329); kept in sync
-            subsidy = 137329;
+        // with hush_commission() — the schedule drops straight to 68664 next.
         } else if (height < 25540000) {
             subsidy = 68664;
         } else if (height < 27220000) {
             subsidy = 34332;
-        } else if (height < 27220000) {
+        // removed unreachable duplicate `height < 27220000` (=> 17166); kept in sync
-            subsidy = 17166;
+        // with hush_commission() — the schedule drops straight to 8583 next.
         } else if (height < 28900000) {
             subsidy = 8583;
         } else if (height < 30580000) {

src/init.cpp

@@ -494,6 +494,8 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-autoshieldinterval", strprintf(_("Block interval between automatic coinbase-shielding rounds (default: %i, min 5)"), 25));
     strUsage += HelpMessageOpt("-autoshieldaddress=<zaddr>", _("Destination Sapling z-address for auto-shielded coinbase (default: reuse or create a wallet z-address). Must be spendable by this wallet."));
     strUsage += HelpMessageOpt("-autoshieldfee", strprintf(_("Fee in puposhis for automatic coinbase-shielding transactions (default: %i)"), 10000));
+
+    strUsage += HelpMessageOpt("-sietch-min-zouts=<n>", strprintf(_("Minimum number of shielded (Sapling) outputs Sietch adds to each z_sendmany transaction as decoys, strengthening amount/linkability privacy. Higher values add privacy at the cost of larger transactions (default: %u, clamped to the range 3-50)"), 7));
     strUsage += HelpMessageOpt("-autoshieldminutxos", strprintf(_("Only auto-shield once at least this many matured coinbase UTXOs exist (default: %i)"), 1));
 
     strUsage += HelpMessageOpt("-deletetx", _("Enable Old Transaction Deletion"));

src/miner.cpp

@@ -249,11 +249,13 @@ CBlockTemplate* CreateNewBlock(CPubKey _pk,const CScript& _scriptPubKeyIn, int32
         {
             // too fast or stuck, this addresses the too fast issue, while moving
             // forward as quickly as possible
-            for (int i; i < 100; i++)
+            for (int i = 0; i < 100; i++)
             {
                 proposedTime = GetTime();
                 if (proposedTime == nMedianTimePast)
                     MilliSleep(10);
+                else
+                    break; // time advanced past the median; stop waiting
             }
         }
         pblock->nTime = GetTime();

src/txdb.cpp

@@ -517,8 +517,14 @@ bool CBlockTreeDB::Snapshot2(std::map <std::string, CAmount> &addressAmounts, Un
         }
         catch (const std::exception& e)
         {
-            fprintf(stderr, "DONE reading index entries\n");
+            // A genuine deserialization/LevelDB error here is NOT normal completion:
-            break;
+            // the for-loop's iter->Valid() already handles end-of-iteration, and
+            // non-address key types are skipped by the chType check above. Swallowing
+            // the exception and building a snapshot from partial data is wrong. Fail
+            // like the inner catch, which the author marked consensus-relevant
+            // ("we need to exit here if so for consensus code!").
+            fprintf(stderr, "%s: LevelDB index iteration exception! - %s\n", __func__, e.what());
+            return false;
         }
     }
     //fprintf(stderr, "total=%f, totalAddresses=%li, utxos=%li, ignored=%li\n", (double) total / COIN, totalAddresses, utxos, ignoredAddresses);

src/wallet/rpcwallet.cpp

@@ -5404,7 +5404,7 @@ UniValue z_sendmany(const UniValue& params, bool fHelp, const CPubKey& mypk)
    // A value of 7 will provide much stronger linkability privacy versus pre-Sietch operations
 	unsigned int DEFAULT_MIN_ZOUTS=7;
 	unsigned int MAX_ZOUTS=50;
-	unsigned int MIN_ZOUTS=GetArg("--sietch-min-zouts", DEFAULT_MIN_ZOUTS);
+	unsigned int MIN_ZOUTS=GetArg("-sietch-min-zouts", DEFAULT_MIN_ZOUTS);
 
     if((MIN_ZOUTS<3) || (MIN_ZOUTS>MAX_ZOUTS)) {
         fprintf(stderr,"%s: Sietch min zouts must be >= 3 and <= %d, setting to default value of %d\n", __FUNCTION__, MAX_ZOUTS, DEFAULT_MIN_ZOUTS );