Better coin detection, correctly detect zcash wallets with no shielded addresses via prefix

wack

@@ -19,28 +19,32 @@ my $avg_xtn_size = 0;
 my $meta         = {};
 
 # guess the coin a wallet.dat came from
+# NOTE: Zcash wallets start out with no shielded addresses
+# and look exactly like BTC wallets, except for address prefixes
+sub is_zec_prefix { $_[0] eq 't1' or $_[0] eq 't3' }
+sub is_kmd_prefix { $_[0] eq 'R' or $_[0] eq 'b'   }
 sub detect_coin {
     my ($c,$meta)  = @_;
-    my $coin = "";
+    my $coin = "BTC";
     print "PREFIX=" . $meta->{prefix} . "\n";
-    my $p1 = substr($meta->{prefix}, 0, 1);
-    # only sapling-enabled coins have these keys
+    my $prefix = $meta->{prefix};
+    my $p1 = substr($prefix, 0, 1);
+
+    if (is_kmd_prefix($p1)) {
+        $coin = "KMD or asset chain";
+    } elsif (is_zec_prefix($prefix)) {
+        $coin = "ZEC/HUSH";
+    }
+
+    # NOTE: Some wallets will have a mix of Sprout
+    # and Sapling keys in same wallet
     if ($c->{sapzkey} or $c->{sapzkeymeta}) {
-        if ($meta->{prefix} eq 't1') {
-            $coin = "ZEC Sapling";
-        } elsif ($p1 eq 'R') {
-            $coin = "KMD Sapling";
-        }
+        $coin .= " Sapling";
     # only zcash forks have these
     } elsif ($c->{zkey} or $c->{zkeymeta}) {
-        if ($meta->{prefix} eq 't1') {
-            $coin = "ZEC/HUSH Sprout";
-        } elsif ($p1 eq 'R') {
-            $coin = "KMD Sprout";
-        }
-    } else {
-        $coin = "BTC";
+        $coin .= " Sprout";
     }
+    return $coin;
 }
 
 while (my ($k,$v) = each %wallet) {
@@ -103,7 +107,7 @@ while (my ($k,$v) = each %wallet) {
 }
 $avg_xtn_size = $counts->{tx} ? $avg_xtn_size / $counts->{tx} : 0;
 
-printf "\n=====Wallet Key Stats=====\n";
+printf "\n=====Wallet $filename Stats=====\n";
 my @keys    = sort { $counts->{$b} <=> $counts->{$a} } keys(%$counts);
 my $numkeys = scalar @keys;
 for my $k (@keys) {