Fix SDV build

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
index a9650e32c30f7f4bc16e87006a6e9cc7ae892c05..0c33a57351fd3ac7962cc27581eff7f31e76aa94 100644 (file)
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -2445,7 +2445,7 @@ __FdoMatchDistribution(
     Text = VENDOR_NAME_STR;
 
     for (Index = 0; Text[Index] != 0; Index++) {
-        if (!isalnum(Text[Index])) {
+        if (!isalnum((UCHAR)Text[Index])) {
             if (Vendor[Index] != '_') {
                 Match = FALSE;
                 break;
@@ -2591,7 +2591,7 @@ update:
     ASSERT(NT_SUCCESS(status));
 
     for (Index  = 0; Vendor[Index] != '\0'; Index++)
-        if (!isalnum(Vendor[Index]))
+        if (!isalnum((UCHAR)Vendor[Index]))
             Vendor[Index] = '_';
 
     Product = "XENBUS";