[PATCH v4 1/3] sxs: check len_name is set

[Hans Chen]

From: Hans Chen

---
 dlls/sxs/sxs.c | 30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/dlls/sxs/sxs.c b/dlls/sxs/sxs.c
index 150a49a322f..2b89bf369f0 100644
--- a/dlls/sxs/sxs.c
+++ b/dlls/sxs/sxs.c
@@ -97,7 +97,7 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
     ACTCTX_SECTION_KEYED_DATA guid_info = { sizeof(ACTCTX_SECTION_KEYED_DATA) };
     ACTIVATION_CONTEXT_ASSEMBLY_DETAILED_INFORMATION *assembly_info = NULL;
     SIZE_T bytes_assembly_info;
-    unsigned int len_version = 0, len_name, len_identity;
+    unsigned int len_version = 0, len_name = 0, len_identity = 0;
     const void *ptr_name, *ptr_version, *ptr_identity;
     SXS_GUID_INFORMATION_CLR *ret = buffer;
     BOOL retval = FALSE;
@@ -160,12 +160,15 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
         const struct comclassredirect_data *redirect_data = guid_info.lpData;
         const struct clrclass_data *class_data;

-        class_data = (void *)((char *)redirect_data + redirect_data->clrdata_offset);
-        ptr_name = (char *)class_data + class_data->name_offset;
-        ptr_version = (char *)class_data + class_data->version_offset;
-        len_name = class_data->name_len + sizeof(WCHAR);
-        if (class_data->version_len)
-            len_version = class_data->version_len + sizeof(WCHAR);
+        if(redirect_data->clrdata_len)
+        {
+            class_data = (void *)((char *)redirect_data + redirect_data->clrdata_offset);
+            ptr_name = (char *)class_data + class_data->name_offset;
+            ptr_version = (char *)class_data + class_data->version_offset;
+            len_name = class_data->name_len + sizeof(WCHAR);
+            if (class_data->version_len)
+                len_version = class_data->version_len + sizeof(WCHAR);
+        }
     }
     else
     {
@@ -199,10 +202,15 @@ BOOL WINAPI SxsLookupClrGuid(DWORD flags, GUID *clsid, HANDLE actctx, void *buff
     ret->pcwszAssemblyIdentity = (WCHAR *)ret_strings;
     ret_strings += len_identity;

-    memcpy(ret_strings, ptr_name, len_name);
-    ret->pcwszTypeName = (WCHAR *)ret_strings;
-    ret_strings += len_name;
-
+    if(len_name > 0)
+    {
+        memcpy(ret_strings, ptr_name, len_name);
+        ret->pcwszTypeName = (WCHAR *)ret_strings;
+        ret_strings += len_name;
+    }
+    else
+        ret->pcwszTypeName = NULL;
+        
     if (len_version > 0)
     {
         memcpy(ret_strings, ptr_version, len_version);