feat: kernel && libDDK: `DDK` and `kernel` improvements.

what:

 - Hardened `AsciiUtils` and `libDDK`

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

3 files changed, 10 insertions, 4 deletions

diff --git a/dev/libDDK/src/ddk_dev.c b/dev/libDDK/src/ddk_dev.c
index 32ec2442..d20684aa 100644
--- a/dev/libDDK/src/ddk_dev.c
+++ b/dev/libDDK/src/ddk_dev.c
@@ -11,7 +11,7 @@
 
 /// @brief Open a new binary device from path.
 DDK_EXTERN DDK_DEVICE_PTR open(const char* devicePath) {
-  if (!devicePath) return nil;
+  if (nil == devicePath) return nil;
 
   return ke_call_dispatch("dk_open_dev", 1, (void*) devicePath, kstrlen(devicePath));
 }
@@ -19,7 +19,7 @@ DDK_EXTERN DDK_DEVICE_PTR open(const char* devicePath) {
 /// @brief Close any device.
 /// @param device valid device.
 DDK_EXTERN BOOL close(DDK_DEVICE_PTR device) {
-  if (!device) return NO;
+  if (nil == device) return NO;
 
   ke_call_dispatch("dk_close_dev", 1, device, sizeof(DDK_DEVICE));
   return YES;
diff --git a/dev/libDDK/src/ddk_io.c b/dev/libDDK/src/ddk_io.c
index c6cdd457..825e82a7 100644
--- a/dev/libDDK/src/ddk_io.c
+++ b/dev/libDDK/src/ddk_io.c
@@ -1,7 +1,9 @@
 /* -------------------------------------------
 
-  Copyright Amlal El Mahrouss.
+  libDDK.
+  Copyright 2025 - Amlal El Mahrouss and NeKernel contributors.
 
+  File: ddk_io.c
   Purpose: DDK Text I/O.
 
 ------------------------------------------- */
@@ -9,6 +11,8 @@
 #include <DriverKit/io.h>
 
 DDK_EXTERN void kputc(const char ch) {
+  if (!ch) return;
+
   char assembled[2] = {0};
   assembled[0]      = ch;
   assembled[1]      = 0;
@@ -19,7 +23,7 @@ DDK_EXTERN void kputc(const char ch) {
 /// @brief print string to UART.
 /// @param message UART to transmit.
 DDK_EXTERN void kprint(const char* message) {
-  if (!message) return;
+  if (nil == message) return;
   if (*message == 0) return;
 
   size_t index = 0;
diff --git a/dev/libDDK/src/ddk_str.c b/dev/libDDK/src/ddk_str.c
index 514cddc7..1e2fde19 100644
--- a/dev/libDDK/src/ddk_str.c
+++ b/dev/libDDK/src/ddk_str.c
@@ -23,6 +23,8 @@ DDK_EXTERN size_t kstrlen(const char* in) {
 }
 
 DDK_EXTERN int kstrncpy(char* dst, const char* src, size_t len) {
+  if (nil == dst || nil == src) return 0;
+
   size_t index = 0;
 
   while (index != len) {