[PATCH 4/8] registry: Fix wrong truncation of Unicode.Length

[Owen Smith <owen.smith@xxxxxxxxxx>]

Assisted-by: ClaudeCode:claude-opus-4.8
Signed-off-by: Owen Smith <owen.smith@xxxxxxxxxx>
---
 src/common/registry.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/common/registry.c b/src/common/registry.c
index 1f7a73c..204e2e8 100644
--- a/src/common/registry.c
+++ b/src/common/registry.c
@@ -1460,11 +1460,13 @@ RegistryAnsiToSz(
     if (Partial == NULL)
         goto fail1;
 
+    ASSERT3U(Length * sizeof (WCHAR), <=, 0xFFFF); // MAX_USHORT
+
     Partial->TitleIndex = 0;
     Partial->Type = REG_SZ;
     Partial->DataLength = Length * sizeof (WCHAR);
 
-    Unicode.MaximumLength = (UCHAR)Partial->DataLength;
+    Unicode.MaximumLength = (USHORT)Partial->DataLength;
     Unicode.Buffer = (PWCHAR)Partial->Data;
     Unicode.Length = 0;
 
-- 
2.51.2.windows.1