From 2910b0434b33277fd660baaeca38f0aad76a38d8 Mon Sep 17 00:00:00 2001
From: Eric <5089238+emizzle@users.noreply.github.com>
Date: Tue, 11 Jun 2024 13:45:02 +1000
Subject: [PATCH] prevent IndexDefect when no parity data

---
 leopard/leopard.nim | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/leopard/leopard.nim b/leopard/leopard.nim
index dd749b9..8be3354 100644
--- a/leopard/leopard.nim
+++ b/leopard/leopard.nim
@@ -142,15 +142,18 @@ func decode*(
     else:
       parityPtr[i] = nil
 
-  let
-    res = leoDecode(
-      self.bufSize.culonglong,
-      self.buffers.cuint,
-      self.parity.cuint,
-      self.decodeBufferCount.cuint,
-      cast[ptr pointer](addr dataPtr[0]),
-      cast[ptr pointer](addr parityPtr[0]),
-      cast[ptr pointer](addr self.decodeBufferPtr[0]))
+  let res =
+    if dataPtr.len == 0 or parityPtr.len == 0 or self.decodeBufferPtr.len == 0:
+      LeopardInvalidInput
+    else:
+      leoDecode(
+        self.bufSize.culonglong,
+        self.buffers.cuint,
+        self.parity.cuint,
+        self.decodeBufferCount.cuint,
+        cast[ptr pointer](addr dataPtr[0]),
+        cast[ptr pointer](addr parityPtr[0]),
+        cast[ptr pointer](addr self.decodeBufferPtr[0]))
 
   if ord(res) != ord(LeopardSuccess):
     return err(leoResultString(res.LeopardResult))