[PATCH v3 2/8] hidclass: Improve error handling in get_device_id

[Claire Girka]

From: Claire Girka

Do not assume the underlying driver will return meaningful data, as it
may not support BusQueryContainerID which will be queried in a next commit.
---
 dlls/hidclass.sys/pnp.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/dlls/hidclass.sys/pnp.c b/dlls/hidclass.sys/pnp.c
index 873c55c4a67..afc7b6e933d 100644
--- a/dlls/hidclass.sys/pnp.c
+++ b/dlls/hidclass.sys/pnp.c
@@ -71,7 +71,7 @@ static minidriver *find_minidriver(DRIVER_OBJECT *driver)
 static NTSTATUS get_device_id(DEVICE_OBJECT *device, BUS_QUERY_ID_TYPE type, WCHAR *id)
 {
     IO_STACK_LOCATION *irpsp;
-    IO_STATUS_BLOCK irp_status;
+    IO_STATUS_BLOCK irp_status = { .Status = STATUS_NOT_IMPLEMENTED, .Information = 0 };
     KEVENT event;
     IRP *irp;

@@ -87,8 +87,14 @@ static NTSTATUS get_device_id(DEVICE_OBJECT *device, BUS_QUERY_ID_TYPE type, WCH
     if (IoCallDriver(device, irp) == STATUS_PENDING)
         KeWaitForSingleObject(&event, Executive, KernelMode, FALSE, NULL);

-    wcscpy(id, (WCHAR *)irp_status.Information);
-    ExFreePool((WCHAR *)irp_status.Information);
+    if (irp_status.Information && !irp_status.Status)
+        wcscpy(id, (WCHAR *)irp_status.Information);
+    else
+        id[0] = 0;
+
+    if (irp_status.Information)
+        ExFreePool((WCHAR *)irp_status.Information);
+
     return irp_status.Status;
 }