From 8bb7e2d40c989475e3245fcc0e6b352a1cd76076 Mon Sep 17 00:00:00 2001
From: Willem Melching <willem.melching@gmail.com>
Date: Mon, 2 Sep 2024 11:55:41 +0200
Subject: [PATCH] bugfixes

---
 src/isotp/mod.rs     | 8 +++++---
 tests/isotp_tests.rs | 4 ++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/isotp/mod.rs b/src/isotp/mod.rs
index 88f1701..6b70b75 100644
--- a/src/isotp/mod.rs
+++ b/src/isotp/mod.rs
@@ -129,8 +129,10 @@ impl<'a> IsoTPAdapter<'a> {
 
         // Pad to at least 8 bytes if padding is enabled
         if let Some(padding) = self.config.padding {
-            let padding_len = CAN_MAX_DLEN - len; // Offset for extended address is already accounted for
-            data.extend(std::iter::repeat(padding).take(padding_len));
+            if len < CAN_MAX_DLEN {
+                let padding_len = CAN_MAX_DLEN - len; // Offset for extended address is already accounted for
+                data.extend(std::iter::repeat(padding).take(padding_len));
+            }
         }
 
         // Pad to next valid DLC for CAN-FD
@@ -208,7 +210,7 @@ impl<'a> IsoTPAdapter<'a> {
     pub async fn send_single_frame(&self, data: &[u8]) -> Result<()> {
         let mut buf;
 
-        if data.len() < 0xf {
+        if data.len() < 0x8 {
             // Len fits in single nibble
             buf = vec![FrameType::Single as u8 | data.len() as u8];
         } else {
diff --git a/tests/isotp_tests.rs b/tests/isotp_tests.rs
index 35eefdb..cfea324 100644
--- a/tests/isotp_tests.rs
+++ b/tests/isotp_tests.rs
@@ -163,6 +163,9 @@ async fn isotp_test_fd() {
         ..Default::default()
     };
 
+    // Single frame with some padding to reach next DLC
+    isotp_test_echo(8, config).await;
+
     // Single frame escape
     isotp_test_echo(62, config).await;
 
@@ -170,6 +173,7 @@ async fn isotp_test_fd() {
     isotp_test_echo(50, config).await;
 
     // Multiple frames
+    isotp_test_echo(218, config).await;
     isotp_test_echo(256, config).await;
 
     // First frame escape