[PATCH 1/1] ntdll: Allocate output string if needed for REG_EXPAND_SZ in RTL_ReportRegistryValue().

[Paul Gofman]

From: Paul Gofman

---
 dlls/ntdll/reg.c       |  9 ++++++++-
 dlls/ntdll/tests/reg.c | 16 ++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/reg.c b/dlls/ntdll/reg.c
index ccf83d59c28..33ad11f4c3b 100644
--- a/dlls/ntdll/reg.c
+++ b/dlls/ntdll/reg.c
@@ -312,11 +312,18 @@ static NTSTATUS RTL_ReportRegistryValue(PKEY_VALUE_FULL_INFORMATION pInfo,
                 res = 0;
                 dst.MaximumLength = 0;
                 RtlExpandEnvironmentStrings_U(pEnvironment, &src, &dst, &res);
-                if (str->MaximumLength < res)
+                if (str->Buffer == NULL)
+                {
+                    str->Buffer = RtlAllocateHeap(GetProcessHeap(), 0, res);
+                    str->MaximumLength = res;
+                }
+                else if (str->MaximumLength < res)
                     return STATUS_BUFFER_TOO_SMALL;
                 RtlExpandEnvironmentStrings_U(pEnvironment, &src, str, &res);
+                str->Length = (res >= sizeof(WCHAR) ? res - sizeof(WCHAR) : res);
                 break;
             }
+            /* fallthrough */

case REG_SZ:
         case REG_LINK:
diff --git a/dlls/ntdll/tests/reg.c b/dlls/ntdll/tests/reg.c
index 2f008d3156d..0e191a125cc 100644
--- a/dlls/ntdll/tests/reg.c
+++ b/dlls/ntdll/tests/reg.c
@@ -2900,6 +2900,8 @@ static struct query_reg_values_test query_reg_values_tests[] =

static void test_RtlQueryRegistryValues(void)
 {
+    RTL_QUERY_REGISTRY_TABLE query_table[2];
+    UNICODE_STRING str;
     NTSTATUS status;
     unsigned int i;

@@ -2923,6 +2925,20 @@ static void test_RtlQueryRegistryValues(void)
                              L"Yellow", sizeof(L"Yellow"));
     ok(status == ERROR_SUCCESS, "Failed to create registry value Color: %lu\n", status);

+    RtlInitUnicodeString(&str, NULL);
+    memset(query_table, 0, sizeof(query_table));
+    query_table[0].QueryRoutine = NULL;
+    query_table[0].Name = (WCHAR *)L"WindowsDrive";
+    query_table[0].EntryContext = &str;
+    query_table[0].Flags = RTL_QUERY_REGISTRY_DIRECT | RTL_QUERY_REGISTRY_TYPECHECK;
+    query_table[0].DefaultType = REG_EXPAND_SZ << RTL_QUERY_REGISTRY_TYPECHECK_SHIFT;
+    status = pRtlQueryRegistryValues(RTL_REGISTRY_ABSOLUTE, winetestpath.Buffer, query_table, NULL, NULL);
+    ok(!status, "got %#lx.\n", status);
+    ok(!wcsicmp(str.Buffer, L"C:"), "got %s.\n", debugstr_w(str.Buffer));
+    ok(str.Length == 4, "got %d.\n", str.Length);
+    ok(str.MaximumLength == 6, "got %d.\n", str.Length);
+    RtlFreeHeap(GetProcessHeap(), 0, str.Buffer);
+
     for (i = 0; i < ARRAY_SIZE(query_reg_values_tests); i++)
     {
         struct query_reg_values_test *test = &query_reg_values_tests[i];