From c939c85a2bda054534f5554522324b003100ee02 Mon Sep 17 00:00:00 2001
From: George Tokmaji <tokmajigeorge@gmail.com>
Date: Sun, 30 Aug 2026 21:27:06 +0200
Subject: [PATCH] Fix UB due to null pointers passed to
 std::slice::from_raw_parts{,-mut} if an empty unicode string has a null
 pointer as buffer

---
 src/unicode_string/str.rs    | 6 +++++-
 src/unicode_string/strmut.rs | 7 ++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/unicode_string/str.rs b/src/unicode_string/str.rs
index ea44ed2..7d14161 100644
--- a/src/unicode_string/str.rs
+++ b/src/unicode_string/str.rs
@@ -33,7 +33,11 @@ impl<'a> NtUnicodeStr<'a> {
 
     /// Returns a slice to the raw [`u16`] codepoints of the string.
     pub fn as_slice(&self) -> &'a [u16] {
-        unsafe { slice::from_raw_parts(self.raw.buffer, self.len_in_elements()) }
+        if self.raw.buffer.is_null() {
+            &[]
+        } else {
+            unsafe { slice::from_raw_parts(self.raw.buffer, self.len_in_elements()) }
+        }
     }
 
     /// Returns a [`U16Str`] reference for this string.
diff --git a/src/unicode_string/strmut.rs b/src/unicode_string/strmut.rs
index 950f2cf..52f8332 100644
--- a/src/unicode_string/strmut.rs
+++ b/src/unicode_string/strmut.rs
@@ -33,7 +33,12 @@ impl<'a> NtUnicodeStrMut<'a> {
 
     /// Returns a mutable slice to the raw `u16` codepoints of the string.
     pub fn as_mut_slice(&mut self) -> &'a mut [u16] {
-        unsafe { slice::from_raw_parts_mut(self.raw.buffer, self.len_in_elements()) }
+        if self.raw.buffer.is_null() {
+            &mut []
+        }
+        else {
+            unsafe { slice::from_raw_parts_mut(self.raw.buffer, self.len_in_elements()) }
+        }
     }
 
     /// Returns a mutable [`U16Str`] reference for this string.